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Tuesday, May 28, 2013

Church Sound: Using Headphones For Live Mixing…Or Not?

Strategies for effective use of headphones, and some downsides
This article is provided by Behind The Mixer.

 

Headphones can be your best friend or biggest hinderance in providing great live sound. 

Headphones are used so you can isolate the sound you want to hear and tweak that sound via volume or EQ settings accordingly. Seems like it would be perfect for using for an entire service, right?

Let’s step back to the sound check for a worship team, made up of, say, a drummer, two guitarists, a pianist, and two singers. A fairly easy group to mix. Listening to them practice, you notice that one of the guitars needs some EQ tweaking. You can tweak in the live environment, but for starters, you don’t know which guitar it is.

Using headphones, you can pipe the mix directly into your ears and thus tune out people talking or other stuff going on in the sanctuary that is making noise. But how do you isolate the guitar so you know which one it is, and, without bothering the worship team? 

Each channel on the mixer has a PFL (pre-fade listen) button. By pressing the PFL button, you isolate teh sound to just that channel – or channels if multiple PFLs are pressed. Now you can use the PFL to identify the specific guitar and tweak the EQ as needed.

Additionally, the PFL is great without headphones when you have one instrument or vocalist that blends with the others but is much louder. The PFL will modify the mixer’s volume display so only the PFL’d channel is reporting it’s volume. This is great for quickly finding the loud one.

Headphones can also be used to mix overall sound. Where I find them deficient is through setting the overall sound for the sanctuary. The volume level via the headphones can be perfect but when the headphones are removed, the volume is too low. They also don’t take room acoustics into account.

By using headphones for channel isolation, you can find and fix the mix for the best sound. However, if you leave them on, you might be the only person hearing that sound.

Ready to learn and laugh? Chris Huff writes about the world of church audio at Behind The Mixer. He covers everything from audio fundamentals to dealing with musicians, and can even tell you the signs the sound guy is having a mental breakdown. To view the original article and to make comments, go here.

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Posted by Keith Clark on 05/28 at 09:19 AM
Church SoundFeatureStudy HallConsolesMixerMonitoringSignalSound ReinforcementPermalink

In The Studio: My Top 10 List Of Compressors

A combination of hardware and DAW favorites
This article is provided by Bobby Owsinski.

 

I was recently intrigued by a really good article on Beatport’s Attack blog called “Top 20 Best Compressors Of All Time.” Since the blog is primarily dedicated to electronic music, you can probably dismiss some of its seemingly dubious entries to the way they’re used creating that type of music.

The article did get me thinking about the top 10 compressors that I like though, so I thought I’d do my own version.

Although the other list was primarily hardware compressors, this list is a combination, since most of us live in a DAW world these days.

Okay, here we go.

1. Universal Audio 1176: I don’t care which version you use, the 1176 is about as close to a desert island compressor as you’ll get due to its versatility. I like to use it on kick, snare, guitars, bass, vocals - just about anything. It can be aggressive sounding, but nothing pulls an instrument out of a mix in the same way.

2. Teletronix/Universal Audio LA-2A: Once again, I don’t care which version of the hardware or software you use, the LA-2A has a sound and feel all its own. It can work pretty well on most instruments, but stands out for vocals, and is dead easy to use. I never use too much, as I like the sound of 2 to 3 dB in most situations.

3. Universal Audio LA-3: Perhaps the ultimate electric guitar compressor, I’ve used it successfully on piano and keyboards as well. Nothing works quite the same with electric guitars in a mix.

4. Fairchild 660/670: When it comes to buss compression, the Fairchild 670 stands is king of the hill for many kinds of music (especially retro or acoustic). It just adds a glue and warmth that you have trouble getting any other way. Just a little bit (a couple of dB) works a lot better than a whole lot. The 660 is the mono version of the more widely known 670, and was the sound you heard on many of The Beatle records (Ringo’s drums, for instance).

5. SSL Buss Compressor: This is the sound that made so many pop and rock records in the 80s and 90s, and it still works great in those genres. I once worked in a studio that had the buss compressor on their 9k labeled as “The Good Button.” Why? Because no matter how your mix sounded, once the SSL buss compressor was engaged, it sounded better.

6. Waves L1: You can’t beat a classic and the Waves L1 is probably the first software limiter that worked so well that it was abused. If used correctly, few limiters are as capable of controlling the peaks of a mix. If used badly, it can suck the life out of a mix faster than you can say “hypercompression.”

7. Empirical Labs EL8 Distressor: Few modern compressors have caught on so widely as the Distressor, and that’s because there are few that are as versatile. I like to track with it on vocals to keep the peaks under control, but there are few compressors that are as effective on room mics, especially when it’s set to “Nuke.”

8. dbx 160: I just love the 160s; any of them. For a punchy drum sound, you can’t beat the hardware 160X’s (or even the A model). In software, the UAD 160 sounds great. My favorite for aggressive kick and snare, but it will pull a piano or acoustic guitar up front as well.

9. Neve 33609: This is another case of a buss compressor that really works well, especially if you only need a little to tighten up the bottom. It’s not always my first choice, but it usually works in a situation when the previously mentioned ones don’t.

10. FMR Audio RNC: The Really Nice Compress (RNC) is a great little hardware unit that provides tremendous bang for buck. I don’t feel that it necessarily excels at any one thing, but it does work well in most situations. For a home studio with not a lot of money to burn, the stereo RNC (and it’s companion RNL -Really Nice Limiter) is a must-have.

Honorable Mention. Pro Tools Native Digirack Compressor/Limiter: I personally think this is one of the most versatile compressors that you can find. It can sound transparent and it can sound aggressive, and since it doesn’t take up much in the way of systems resources, you can use a lot of them in a big mix. Don’t overlook it.

Once again, these are my personal opinions because these are what I always use. There’s lots of other great ones out there (especially in software), but I’ve come to rely on these units because I know what they’ll do in most situations.

Bobby Owsinski is an author, producer, music industry veteran and technical consultant who has written numerous books covering all aspects of audio recording. For more information be sure to check out his website and blog.

 

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Posted by Keith Clark on 05/28 at 08:20 AM
RecordingFeatureBlogProductDigital Audio WorkstationsProcessorStudioPermalink

Friday, May 24, 2013

Church Sound: Turning “More Me” Into Quality

Sometimes it's wise to remember the old adage "less is more"

What is it about sound engineers and musicians getting along?

In my experience, getting these two groups in sync is like putting angry cats in a room full of dogs. Sometimes there’s enough tension that it feels as though a fight is going to break out.

While commissioning a sound system in another state, my friend Jeff saw the cats and dogs ready to brawl, and also picked up some new lingo that I’d like to share with you here.

During the final rehearsal before the opening Sunday at a new church building, Jeff, having finished commissioning the system, was hanging at the tech booth, listening to and watching the worship band rehearse. 

The all-too-typical scenario played out—the musicians on stage kept asking for more monitor. The mix engineer, doing both house and monitors, was struggling to get any clarity in the house mix because the wash from the stage was overtaking the room. 

To remedy the situation, he was subtly backing down the level of the stage monitors as he boosted the level of the main system. Not necessarily a bad plan, a bit sneaky, but sometimes you do what you have to do. If he kept escalating the monitor level, there would be no hope of having a decent mix.

After a while—and a 9 dB reduction in stage volume—one of the singers demanded more monitor. The engineer, undaunted, resorted to a sleight of hand move, acting like he was turning up the monitor, all the while smiling at the stage.

This move seemed to satisfy the singer, at least for a few minutes, but then in the middle of the next song, as he struggled to keep his pitch, he stopped singing and shouted into the microphone “More Me Monitor,” turning red in the face. He then emphatically pointed to the monitor in front of him and once again yelled “More Me Monitor!” 

The engineer, still undaunted, calmly turned to Jeff and asked “Can you get me some M3 technology for this system?”

Jeff, wondering just what “M3 technology” might be, rose out of his chair and headed toward the mixing board. 

The engineer again asked Jeff, “Can you get me some M3 technology for this system?”

Jeff, playing it cool and acting like he was in the loop on this mysterious “M3 technology,” replied, “What kind of M3 technology are you looking for?” 

The engineer’s answer caused him to break out in laughter: “You know, the ‘More Me Monitor’ type, better known as M3 technology”.

After he and the engineer stopped laughing, Jeff decided to use this as a teaching moment. He called the rehearsal to a halt and then gathered the musicians and the tech team in the front pews, and explained to the musicians how, quite often, “less is more.” They don’t need to hear every instrument in every mix. In fact, doing that just clutters the stage sound, making it harder for everyone to hear what they actually need to hear.

He went on to explain to the tech crew that if the musicians can’t hear themselves, you don’t even want to turn on the mains because the musicians will be off key and not playing well together. 

Jeff was then able to walk each musician through what he suggested that each needed in his/her monitor, and at the same time, help the engineer realize that some stage volume is necessary if you want the musicians to play with confidence and sing on pitch. 

At the end there were no hard feelings (though there could have been), and other than the shirts that the tech team now wear that say “Powered By M3 Technology,” this potential brawl was soon completely forgotten.

It’s times like this that remind us to put technology to productive use in worship, and not the other way around.

Gary Zandstra is a professional AV systems integrator with Parkway Electric and has been involved with sound at his church for more than 25 years.

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Posted by Keith Clark on 05/24 at 04:11 PM
Church SoundFeatureBlogStudy HallBusinessEducationEngineerMonitoringSound ReinforcementTechnicianPermalink

In The Studio: Listen, And They Will Come…

Everything you work on will be better if you just listen first
This article is provided by the Pro Audio Files.

 

Dusk had settled in, and I was on my way to the studio. Excitement ran through my veins like high-octane fuel through a well-tuned engine. I had been invited by a student at a local recording and audio production school to come in for a free recording session…

Upon arriving at the studio…

The engineer wasn’t anywhere to be found, nothing was set up, and I sat in a less-than-plush lobby. “Wow…” was all I could meekly muster in my mind.

To make what could be a very long story shorter, it took hours to set up for the session, the engineer didn’t have a good grasp on anything audio related, and I never heard anything regarding final mixes.

BUT WAIT! Some good did actually come from this experience. After the first take, I looked into the control room and through my microphone, I asked the engineer what he thought … silence … the mood was almost uncomfortable, when the engineer finally piped up, he said, “Oh, were you talking to me? Sorry… I wasn’t listening…”

At that moment, I realized I could be a far better engineer and producer, by simply becoming a better listener. From that moment, I made it a goal, and began taking the steps to start my own studio and production company.

Not Listening!? Absurd…
Can you even think of a worse thing to say, sitting in a control room, behind a console? I think not! And so, listening first has always taken priority in my work. Everything you choose to work on, all of your music, every production, will be better if you just listen first.

And even more importantly, everyone you work with will appreciate you much more than “the other guy.” Whether it’s friends or professional clients, listen first and you will have more than you ever dreamed.

What’s the first thing you do when you get a new artist in the studio? Of course, you want to be prepared and ready to go when they arrive. 

But beyond that, do you listen to their tracks first? Do you talk to them in the lobby and get to know them personally first? Do you start laying down scratch tracks right away? Fill in the blank with your own idea, then read on…

To me, the absolute most important way to make a great recording and have a happy client is to find out what motivates the artist, why they write music, and what they want to communicate.

If you don’t know these details, it will be impossible for you to realize what the artist has in mind. It will be impossible for you to guide them through the creative process of recording.  Many engineers and ‘producers’ always work a certain way. They always get a certain sound.

And you know what? Every artist or band that comes to them ends up sounding the same. Before you know it, the local scene has 10 bands that all put out the “same” album.

Now where do the fans go? To a new, inspired, talented act. And it’s not because the band or artist isn’t good, it’s because they were pulled in a different direction than where they really groove and where they really feel the music. I believe fans are aware of this subconsciously.

Our job in the studio is not to “push” all of our artists into the sound that we personally like, No! Our job is to listen! Listen and help the artist make music in their own way, in the way that they can feel best. And you can’t do that until you put yourself in the artist’s shoes and learn what drives them forward.

So next time you’re setting up for a session and you pull out your favorite microphone for guitar, your favorite microphone for vocals, and so on… think about your artist first.

Do they really need or want that sound? Does their music require something different? Do you need to try something you’ve never tried before?  No one can tell you these answers except you and your ears. Do yourself and your artists a favor and listen first, before you make the same album you’ve made for the last 10 years. 

I already know plenty of engineers who fall into that category. Let’s not add another…

Internationally awarded and recognized, Charles Szczepanek has enjoyed performing for diverse audiences as well as engineering and producing for many highly-respected artists across multiple genres. Additional personal achievements include multiple international prizes for piano performance, recognition by Steinway for “Outstanding Piano Performance,” as well as awards in music composition, ensemble direction, and vocal performance.

Be sure to visit the Pro Audio Files for more great recording content. To comment or ask questions about this article go here.

 

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Posted by Keith Clark on 05/24 at 02:01 PM
RecordingFeatureBlogDigital Audio WorkstationsEngineerStudioTechnicianPermalink

Gregg Brunclik Of Clearwing Productions: It’s All About Building Something

From a small audio company to a one-stop shop capable of fulfilling virtually any production need

“Ever since I drove my first drywall screw into my mother’s coffee table, I’ve had a passion for building things,” says Gregg Brunclik.

Originally that manifested itself as a desire to build things with his hands, he adds, including the first loudspeakers his company, Clearwing Productions, offered to its clients.

While that passion has evolved over time, it’s been integral to success of Clearwing since day one, and well before the company incorporated in 1985.

Over time, the Milwaukee-based company has grown from a small audio company to a one-stop shop capable of fulfilling virtually any event or venue’s production needs – lighting, sound, backline, staging and video, portable power, transportation, and full design/install services.

The customer base is just as diverse, and includes corporate and house of worship clients, touring acts, and large-scale multi-stage events such as Milwaukee’s legendary Summerfest.

One of the most important factors in that growth is Brunclik’s willingness to turn on a dime to seize an opportunity, even it if means growing in multiple directions simultaneously. “At one time, some people made sport of our business by calling us ‘Clearly Winging It,’ and we have blown in the wind a little bit,” he admits, “but we’ve gone where opportunities are – if a reasonable return on your investment is possible, it doesn’t really matter what market segment it’s in.”

At the outset, the focus was on meeting the evolving needs of the Milwaukee regional market rather than conforming to a rigid business plan in the hopes the market would embrace it. “I started as a sound guy in a garage with a tiny system,” he explains. “I didn’t have wealth to invest in a lot of gear immediately and maybe it took a longer time for us to grow than some, but because we live in a such a huge festival city, our market drove us to expand.”

Diving In

Brunclik laughs often, displaying a ready sense of humor that’s clearly reflected in the company’s culture. His own bio on the company website describes him as president/CEO, loan signer, and feeder schlepper.

Brunclick in the Clearwing shop. (click to enlarge)

“I put the last part in there for a reason,” he notes. “The only way to build a team is to be part of it. If I go to a show and people need a hand loading out, I’ll dive in. The best way to inspire people to do whatever it takes to get a job done well is to show them I’m willing to do that myself.”

Born in Sturgeon Bay, WI, he grew up in Madison before attending high school in Milwaukee. During high school, his ability to adapt asserted itself during his first gig in the entertainment business. “I was very enamored with music when The Beatles broke in the U.S. and I played drums in high school, but the first band I joined already had a drummer, so I played keyboards.” In 1968, when the band morphed into a country act and replaced him with a pedal steel player, he adapted again and took on running front of house sound.

Brunclik did a brief stint at the Milwaukee Area Technical College electronics program, but built up his engineering chops on the job. By the time that first band broke up, he had acquired a small inventory of gear, enough that he and another local engineer could pool their collective resources and take on local one-off club gigs.

One of those gigs was doing sound for country singer Eddie Rabbit, whose career was just taking off at the time. Rabbit was so impressed he took them on long term. “He asked if we could be in northern Oklahoma in three days, and we toured with him for the next five years.” Soon after, they picked up a tour with Blackfoot, where the support act, Def Leppard, was just undertaking its first U.S. tour.

Off & Running

At the time, the company had adopted the name Clearwing Audio, Brunclik says, and had just one arena system comprised of proprietary loudspeaker boxes built and developed with Mark Gander, later of JBL Professional.

“It was a groundstacked system called an LRC – double 18s, double 12s, a 2” compression driver and two bullets in each box. My dad co-signed a loan for $70,000 to build it and we were off and running.”

Brunclik toured relentlessly, once spending 200 consecutive days on the road, but eventually the life took a toll on him and his marriage, prompting him to head home with an eye toward building a regional company from scratch.

“I never took to the tour bus life; it just wasn’t the right chemistry for me, and I wanted to see my kids grow up.”

For three years, he operated Clearwing as a one-person shop out of a 2,000-square-foot warehouse. By 1985, he’d bought his previous partner out, incorporated, hired additional staff and moved into a 5,000-square-foot facility. He’d also taken steps to get his personal life back on track. “I got clean and sober in 1985, started my climb and I’ve never looked back.”

Over the next few years, Clearwing consistently upped the ante in terms of the equipment and services it offered. Traditionally, a large percentage of the business was supplying audio for clubs, but as the years went by, the company took on a larger chunk of the thriving regional summer festival scene, including Summerfest. Initially tapped to provide production for only one stage, now the company serves the entire festival’s needs, roughly 14 stages in all. 

Brunclick mixing a show circa 1978. (click to enlarge)

Seize The Moment

Sometimes expansion required “going out on the thin branches,” Brunclik notes. “I borrowed money, paid it back, borrowed again, paid it back, and we re-evaluated our model several times to look at the return time on our investment.” Though it may have been risky at times, it was necessary, not only to make the most of every opportunity that came along, but to do so at the right moment.

Perhaps no opportunity helped spur growth more dramatically than one he seized during a visit to Sunbelt Phoenix Studios while vacationing in Arizona in the 1990s. “I had this habit of opening up the phone book and seeing who the players were in other markets, so while I was there we went over, knocked on Sunbelt’s door and got to talking. They primarily did staging and lighting, and we supplied audio and a bit of lighting.

The Clearwing crew preparing to fly its L-Acoustics K1 arrays at Summerfest in Milwaukee in 2010. (click to enlarge)

“We also realized our busy seasons happened at inverse times of the year. So we developed something we called the ‘NAFTA of production’ – in the winter, I’d send audio gear to them and in the summer, they’d send me a roof and lighting.”

The goal was to help each other expand into new market segments using their partner’s inventory. Although the partnership lasted over a decade, ultimately Sunbelt folded in 2003 owing to an internal dispute. Around the same time, another provider, Masque Sound, closed its Phoenix office, leaving a hole in the market Clearwing could fill without Brunclik stepping on the toes of any friends and former business partners.

The company has diversified even further in recent years, offering event-planning services as well as full production. Additionally, both the Milwaukee and Phoenix locations now have “pro shops” providing everything from gaffers tape to lighting gels and gloves to clients.

An installation division to service corporate clients has also taken on a number of high profile projects, including Cowboys Stadium in Dallas in 2008. Also in the portfolio is Big Event Specialists, a separate trucking company that provides system transportation services.

Many Paths

While Brunclik’s ability to adapt has been a key driver in Clearwing’s growth, he also credits his staff for their efforts.

Some of them are family, including niece Courtney Brunclik, who, along with Phoenix general manager, Dave Temby, has been instrumental in the overhaul and update of the company’s website in early 2012.

His son Bryan, now VP of sales, has also discovered a passion for the production business, but being family doesn’t win anyone special treatment, Brunclik says, laughing again. “I made Bryan start by polishing feeder cable.”

Today, Clearwing Productions occupies a 40,000-square-foot warehouse in Milwaukee and a 20,000-square-foot warehouse in Phoenix, staffed by about 50 full-time employees. While sound and lighting are still the largest percentage of the business – followed by backline – the expansion of their video inventory has become increasingly important for servicing the needs of corporate clients and special events.

And in order to expand the reach overseas, Clearwing has recently joined the AV Alliance, a worldwide consortium of production companies focused on enhancing each individual member’s ability to provide production for events anywhere in the world with the same degree of continuity, technical precision and service as they would in major markets in the U.S. and EU.

Clearwing supporting Steve Miller on tour last year. (click to enlarge)

Brunclik has also prospered in more personal ways, by building the life he’d envisioned when he got off the road. “Family and faith and a variety of other things are important to being a well-rounded person,” he says, “and my biggest pride and joy are my nine children. My oldest is 34 and my youngest is five.”

He remains keenly interested in the technological evolution of production technology as well as the cultural evolution of music. “I’m into Electronica now for some reason; Tiesto, Armin Van Buuren and all those DJ cats.”

It’s been years, however, since he’s manned a console himself. “I still have a strong passion for music, so it is a little bit heartbreaking, but I love what we do because it’s still about building something. One of the greatest thrills for me is to go to a festival we’re involved with and see a stellar finished product. I really get my strokes when I can stand out in front of an awesome looking and sounding show, and know that we provided everything from the sod up.”

Based in Toronto, Kevin Young is a freelance music and tech writer, professional musician and composer.

Brunclik has also prospered in more personal ways, by building the life he’d envisioned when he got off the road. “Family and faith and a variety of other things are important to being a well-rounded person,” he says, “and my biggest pride and joy are my nine children. My oldest is 34 and my youngest is five.”

He remains keenly interested in the technological evolution of production technology as well as the cultural evolution of music. “I’m into Electronica now for some reason; Tiesto, Armin Van Buuren and all those DJ cats.”

It’s been years, however, since he’s manned a console himself. “I still have a strong passion for music, so it is a little bit heartbreaking, but I love what we do because it’s still about building something. One of the greatest thrills for me is to go to a festival we’re involved with and see a stellar finished product. I really get my strokes when I can stand out in front of an awesome looking and sounding show, and know that we provided everything from the sod up.”

 

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Posted by Keith Clark on 05/24 at 01:58 PM
Live SoundProductionFeatureProductionAudioBacklineLightingStagingVideoBusinessEngineerSound ReinforcementPermalink

Making It Meaningful: Practical Applications Of Loudspeaker Analysis

Hearing the problem is not the same as quantifying the problem

Over the years many have debated the relative merits of “looking at screen traces” on an analyzer versus using human hearing to determine how a loudspeaker, or an entire system, actually performs.

While both practices are of course valid, it’s extremely difficult for the human ear to detect, characterize, and correct small deviations in frequency and phase response, and even harder to characterize driver distortion in a meaningful manner.

Likewise, the ear is often stymied when attempting to typify transient response across the spectrum. This is particularly true in the lower frequencies where slow cone acceleration and deceleration can produce a bigger, warmer sound – dependant of course on the program material, the room acoustics, and the listener’s perception.

By listening, we all can tell if a system sounds ragged and distorted; we know when a system is bass heavy or too trebly; we usually know when a note or two stands out unnaturally. But unless we play long passages of music in many different key signatures, it’s all too easy to miss the problem of uneven frequency response, especially if it’s confined to a narrow bandwidth.

And unless we’re willing to subject our ears to varying levels of distortion at high sound pressure levels (bad idea!), it’s nearly impossible to characterize the distortion products of a given driver, or loudspeaker system, in relation to other drivers and other loudspeaker systems.

Finally, if we haven’t trained our ears to a super-human level, we’re going to have an extremely hard time identifying gradual shifts in phase response, let alone what to do about them. This doesn’t mean that we aren’t able to hear the negative effects of distortion, frequency, and phase irregularity; what we’re saying is that hearing the problem is not the same as quantifying the problem and then developing a solution to correct it.

More Useful
While it’s never a good idea to ignore what you hear in favor of what you see on an analyzer display, the information that an audio analyzer can provide will help enormously whether your task is to optimize a sound system that’s already in place, EQ a simple pair of loudspeakers on sticks, or design a superlative loudspeaker system from scratch.

And as I’ve pointed out in the first two articles in this series (here and here), an analyzer with narrow-band resolution is vastly more useful than a simple octave or third-octave portable device.

Let’s look at acquiring a distortion measurement as one important example of what an analyzer can do for you beyond just displaying a frequency response curve. Some analyzers offer distortion measurements as a built-in function, notably certain models manufactured by Audio Precision (Figure 1).

Figure 1: An ultra-advanced AP 2700 Series Audio Analyzer. (Computer not included.)

Distortion, in its many forms, is virtually always a function of signal level, but not always in a linear fashion. A linear device, such as a good quality pre-amplifier or power amplifier, will exhibit harmonic distortion products that remain at the same ratio to the test-tone fundamental signal – until the device becomes non-linear due to excessive level, at which time the harmonic distortion increases at a non-proportionate rate (Figures 2 and 3, next page).

The distortion products of a well-designed loudspeaker may remain linear at a wide range of power levels, but it’s a safe bet that as maximum power handling is approached, most loudspeakers will exhibit non-linear, even runaway distortion response.

I’ve investigated low- and high-frequency drivers for many years; in some cases, as the driver comes close to burnout, the second and third harmonic distortion products actually exceed the level of the fundamental frequency that’s exciting the driver for the test. This equates to more than 100 percent distortion, counter intuitive as that may be.

Incidentally, when running such tests, it’s strongly advised to wear serious hearing protection, and even then, the sonic signature is anything but pretty.

A very useful routine that’s built into some analyzers for measuring distortion continually increments the drive level to the DUT (device under test) so that the operator can view the effect of level versus distortion versus frequency. This is important because measuring distortion at a single level or a single frequency won’t tell you much.

The distortion characteristics of an 800-watt woofer with 1 watt of power applied will not be the same as when 800 watts are applied. Nor will the harmonic distortion at 30 Hz be the same as at 100 Hz (hint: it will be significantly higher at 30 Hz and at 800 watts). The use of an analyzer will reveal these conditions without having to sacrifice your hearing by trying to determine them by ear.

Fighting Distortion
But what if you don’t happen to have an analyzer equipped with distortion measurement capabilities? Distortion can still be measured with an FFT (fast Fourier transform) or other narrow-band analyzer, but the process requires a bit more effort.

To make a harmonic distortion measurement, a low-distortion sine wave source is needed. If an analyzer doesn’t have a built-in adjustable-frequency sine source, an outboard generator can be used. Make sure that the sine wave generator is as pure and distortion-free as possible.

By applying a low distortion fixed sine wave to the DUT, and looking at the spectral content of the DUT, you can see the magnitude of the harmonics that are not present in the test signal. Since most loudspeakers produce one or two orders-of-magnitude greater distortion than most electronic equipment (amplifiers, pre-amps, etc), we’ll use a loudspeaker as an example. Figure 2 shows a typical screen commonly seen when viewing distortion on an FFT.

Figure 2: The amplitude of the fundamental frequency applied to the loudspeaker, followed by a decreasing series of harmonics generated by the loudspeaker’s distortion characteristics. The loudspeaker is being driven at a moderate level.

The fundamental tone from the generator is the tallest trace at the left of the screen. For this example, let’s say it’s set at 100 Hz. An ideal loudspeaker would reproduce only the 100 Hz tone and nothing more.

However, there are no perfect loudspeakers. So what is produced is a series of harmonics that are the loudspeaker’s distortion products. In other words, unwanted energy content that the loudspeaker is emitting but not being excited with. 

As the drive level to the loudspeaker is increased, the fundamental will increase in amplitude. If the loudspeaker is linear, the harmonics will increase proportionately. As the level continues to increase, and the loudspeaker eventually becomes non-linear, the amplitude of the harmonics will increase at a rate that is greater than that of the fundamental.

Figure 3 depicts the distortion signature of a loudspeaker that’s become significantly non-linear due to the power applied. If even more power is applied, the second and third harmonics may even exceed the level of the fundamental, and/or the loudspeaker will be damaged.

In order to properly characterize a loudspeaker’s distortion across the full spectrum that it’s intended to reproduce, measurements must be taken at many different frequencies.

Figure 4: The same loudspeaker as seen in Figure 2, but operated at a higher drive level. Note how the ratio of the harmonics to the fundamental have changed significantly. The second harmonic is now nearly as great in magnitude as the fundamental itself.

It’s better if they’re not octave-band related because the same problem (or lack thereof), usually stemming from some form of resonance, is likely to be repeated when the distortion products are harmonically related to a previous measurement.

In other words, once you’ve measured distortion at 100 Hz at various power levels, increase the frequency of the oscillator to 110 Hz, then 125 Hz, then 133 Hz, and so on, rather than jumping ahead to 200 Hz.

There is no hard and fast rule, but the greater the number of measurements taken, the better understanding you’ll have of the loudspeaker’s behavior. After spending a day or two doing this manually, it becomes quite evident that a distortion measurement routine, pre-programmed into a modern analyzer, can compress many hours of work into mere minutes. 

Various Approaches
While this is slightly off-topic, methods do exist to reduce distortion once you understand how and why it’s being generated. With a LF loudspeaker, the enclosure’s tuning can be optimized for a specific task if it’s possible to alter the port area and port length.

If an application doesn’t need 25 Hz reproduction but demands a lot of power at 40 Hz, re-tuning the enclosure by changing the ports may reduce the distortion considerably at 40 Hz, and the transient response will probably improve too, as a byproduct.

Another approach is to use more PA than you might normally think is needed. The Grateful Dead were big on this concept, sometimes putting stadium-sized loudspeakers into small theatres. The reason this works is because most modern loudspeakers exhibit respectable distortion figures at low to moderate operating levels, but not necessarily when they’re being pushed hard.

Therefore, if the PA isn’t being operated at the upper end of its power output capability, then the sonic quality will likely be clearer and more natural, providing (of course) that the additional loudspeakers are not causing destructive acoustical interference among one another.

Yet another approach is to introduce protective limiters that are set to engage before the loudspeaker’s distortion products enter the dreaded non-linear zone. The use of an analyzer will greatly assist in determining where to set the limiter threshold and ratio, but time constants are a different matter.

Unless you have advanced test and measurement skills – and plenty of time to use them – it’s likely that you can arrive at perfectly usable attack and decay settings by ear. Make sure to use music that has similar instrumentation and dynamic content as the program material of the actual show.

Among the myriad of functions that modern audio analyzers can perform, one that stands out is the waterfall plot. Waterfall plots have their roots in mathematics, long before analyzers existed. They expand on the familiar X-Y Cartesian plot by including a third axis that reveals a new dimension to the information being viewed.

Waterfall plots can be used to display many things, but one of exceptional value is the ability to view the frequency response of a loudspeaker, while at the same time viewing its acceleration and deceleration characteristics, also referred to as transient response (Figure 4).

Figure 4: A sample Waterfall plot.

It’s fascinating to see how some segments of the audible spectrum keep decaying from kinetic energy, while others have already stopped. These measurements are helpful in evaluating a new loudspeaker system or working with an existing one to improve its dampening characteristics.

Note The Differences
While a number of suppliers have introduced value-priced measurement microphones during the past few years, they’re usually intended for use with a loudspeaker controller and are suited only for measuring an approximation of frequency response. It’s important to understand that there’s a significant difference between a mic that’s been designed for a quick frequency response measurement and one that’s painstakingly crafted for flat and linear frequency response, phase response, impulse response, and distortion measurements at a wide range of sound pressure levels.

The long-standing leaders in the field, such as Bruel & Kjaer, have spent decades fine-tuning the efficacy of their products. For truly accurate information when measuring a loudspeaker system, particularly as it applies to distortion and impulse response, a highly accurate measurement mic that’s mated with a compatible mic pre-amp must be used.

There’s a lot more to discuss when it comes to measuring and understanding audio devices; a serious treatment would fill a sizeable book. Today a plethora of analysis products exist that offer varying degrees of usefulness, accuracy, and efficiency for the vast range of tasks that sound system designers and engineers need to accomplish.

Those with the luxury of time and budget will want a complex and versatile analysis system, while others – i.e., a touring club engineer with little time to run a sound check before catching dinner on the fly – will likely want a less costly, portable solution.

Ken DeLoria is senior technical editor for Live Sound International and has had a diverse career in pro audio over more than 30 years, including being the founder and owner of Apogee Sound.

{extended}
Posted by Keith Clark on 05/24 at 10:20 AM
AVFeatureBlogStudy HallAVDigitalLoudspeakerMeasurementSignalSystemPermalink

Thursday, May 23, 2013

Chat From The Past: System Designer Craig Janssen On Measurement, Loudspeaker Design & More

The views and approaches of an innovator

Enjoy this lively PSW live chat session with noted sound system designer Craig Janssen of Acoustic Dimensions. It provides an interesting look at what was happening in the world of system design a decade ago, and much of what Craig addresses is timeless, regardless of specific gear.

Moderator: Greetings Craig! And welcome, everyone, to the chat. Let’s get started.

Charles: What analysis packages do you use for designing and tuning systems and why?

Craig: For designing we use a number of packages. We have JBL CADP, EASE, F-Chart (EAW), EV Array show, Renkus ALS and George Augspurger’s custom program. We use different programs to solve different problems. CADP2 for coverage, and array programs to model array behavior. As for “tuning,” we own and use a bunch of stuff.

Mostly I use Smaart and TEF. Mostly Smaart though.It allows us to get quick and accurate measurements from a variety of clusters. We use a Soundweb to switch up to 6 mics. Usually I use 2 computers concurrently, one in measurement mode and one as resultant.

Moderator: We have a couple related follow-up questions…

yamama3000: What is the F-Chart and how does it work?

Craig: F-chart is a custom program from EAW (not sold) which allows extremely accurate predictions of device interaction. It’s a pain to use, but provides tremendous accuracy and allows each device to have filters inserted upon it and adjusted, and then predicts the results.

Brendan: Do you feel Smaart has gained equal acceptance as TEF?

Craig: I think that Smaart has surpassed TEF for industry acceptance by a wide margin.

Michael: So no go on the SIM system? How come?

Craig: As to Meyer SIM, I am supposedly “qualified” (been to training) but can’t justify the cost of the unit. Also it is not nearly as flexible as Smaart for complex system tuning. If I was on the road touring, I would love to have SIM.

lilbob: Which of these (software) in your opinion gives the most accurate actual HF coverage results in both the design and after the install?

Craig: All of the prediction packages (as they relate to sound coverage) are limited by the accuracy of the information provided by the manufacturers. Most info is a little suspect in that until recently has all been in 10 degree increments. Need at least 5 degrees for good accuracy.

Also these programs do not consistently predict interference accurately. The prediction of coverage is being complicated by the use of “shaded array” systems which have (currently) no way of being inserted in modeling programs. EASE and others are working on this.

Charles: What makes SIM better for road use than Smaart? Or are they equal?

Craig: SIM is extremely good at allowing you to use repeatable configurations (called branches) which switch mics on and off and reconfigure the delays. Additionally SIM has 3 separate DSP processors which allow 3 concurrent measurements. Smaart is only 1 processor (unless you use multiple computers, which is clunky at best.)

Tucci: Could you explain your dual computer use within a Smaart measurement rig? I don’t follow what you said.

Craig: Tucci, I assume that you have knowledge of Smaart?

Tucci: Yes, I do

Craig: I use one computer to measure the response. Using same computer I switch to the EQ input and reverse the trace. Thus as I adjust the response, I can’t see the result. I run a second computer so that I can see the response in real time.

Chris Kathman: Have you ever seen the SpectraFoo program ?

Craig: Yes, but only briefly. Not enough to discuss it intelligently….

Jeff Waluch: The Potters House install was quite impressive, How did you come to your component decision?

Craig: Potters House is an interesting project (understatement…) because of the tremendous sound pressure levels that needed to be achieved, even with a lav mic. Basically the system is capable (and needed) of getting to around 125 dB at the console.

To get this level, we needed really powerful and compact speakers. There are limited options for this. We chose to use the EAW KF900 series. Probably could also have done it with (L-Acoustics) V-DOSC.

Chris Kathman: Wally or Craig, maybe you could tell the viewers at home what Potter’s House is.

Craig: Potters House is a 8,200-seat church in Dallas.

Chris Kathman: Wow! How many zones/delays?

Craig: Left-center-right cluster each with 3 KF900 MH boxes and 4 (4x15” drivers) cabinets. First delay was 12 ASV7652 boxes (2x15, 2x10, 1x2”) and rear delay of 16 boxes (12 and 1”).

Charles: Why was there the need for 125 dB at the console in a church? Even allowing 10dB for headroom, that’s 115 dB average!

Craig: The pastor of this church is T.D. Jakes, who does a lot of stadium gigs and is used to concert levels. Also the crowd is so LOUD that the system has to get over them. I know it sounds crazy…but you have to be there. Of course they only hit those levels for brief moments of time.

yam4000vca: Did the client specify that 125 dB level number? I have done quite a few kickin’ churches and never needed that much.

Craig: The client insured that I went to one of their arena gigs and wanted me to understand that they did not want to run out of system for any level of concert that they might do. 125d B is just what the system is capable of, not what they run it at all the time.

Michael: Is Potters House the place with the 3 Innovasons - house/mon/video?

Craig: We specified the Yamaha PM1Ds for this project (3 units) but as they have not been released yet, they currently have a 64-channel Soundcraft Series 5 and a SM20 at console.

lilbob: Who supplied the equipment for you on the Potter’s House install?

Craig: SPL

yamama3000: Can you explain “beam steering” and it’s advantages?

Craig: Beam steering is the technique of loudspeaker placement and signal processing implementation that allows you to control and direct the projection of sound. A simple example: Say you are on stage with side stacks of sub-bass, it is a relatively easy task to position the subs so that you achieve a null in energy projection to the center of the stage.

Michael: How does beam steering work?

Craig: It’s pretty simple really. If two waves from a speaker (any frequency) coincide at the same path length, then we get 6 dB of summation. If they are spaced apart by 1/2 wavelength of the frequency of interest, then they cancel completely. It’s using this cancellation that is tricky.

yamama3000: When you say “loudspeaker placement” are you talking about the boxes themselves or the drivers within the boxes?

Craig: If we look at the sub bass example, then spacing the subs 8 feet apart horizontally will result in at least 15 dB cancellation at 65 Hz at 90 degrees off axis to the plane of the subs. The wavelengths don’t care if the drivers are in the same box or in different boxes. What counts is the spacing and the frequency of interest.

Brendan: With so many production boxes on the market, why do we still see so many “customs boxes” in bid packages.

Craig: Broad question this. It may be that the project needs a particular rigging solution… or the coverage of available boxes does not work. We used to use lots of custom boxes, but most of the products now exist and solve our problems, so we usually only do extensive custom for stadiums, theme parks, etc.

yamaha3000: And what do you think about the whole line array explosion from the manufacturers?

Craig: Line arrays have of course existed for over 40 years now and are all based on the physics papers published in the early 1950s. They solve lots of problems in the vertical plane…can also get you in trouble, but are limited in horizontal plane.

Chris Kathman: Get you in trouble how?

Craig: Line arrays (similar to V-DOSC) tend to have very defined vertical pattern control but loose horizontal control. This is not a negative in itself, but it does mean that you need to keep them spaced apart by at least one wavelength at the lowest frequency of usage unless you want horizontal LF interference.

yamama3000: How are the manufacturers getting around the copyright laws concerning horn flares which make the VDOSC work?

Craig: I can’t tell you exactly what the V-DOSC patent covers, but I can tell you as a patent holder that there are many ways to circumvent the process. The competing manufacturers (EAW, JBL, EV, etc.) will all say that they are not infringing the patent. Note that the patent does not cover line arrays, but the HF waveguide itself.

Moderator: Craig, I’d like to go back to the beam steering topic if we may…We have a couple follow-up questions.

Craig: Shoot.

Michael: Is there any written text or paper that explains how to use beam steering effectively—examples of productive use and problem solving? If not, will you consider issuing such?

Craig: Lots of papers available. Beranek “Acoustics” and Olsen “Acoustics” are both excellent. Beranek is no longer published, but Olsen is published by American Acoustical Society. Many, many papers published in AES journals. Some good…some confusing.

Tucci: But how wide a range can you effectively null? What’s happening at 80 or 100 Hz in your example?

Craig: At 80 or 100 Hz you will have about 6 dB drop, same at around 30 Hz. If subs go higher, say 140 Hz, then you will get a side lobe as loud as the front lobe and a null at 45 degrees. Nasty.

yamama3000: Is beam steering Showco’s whole “secret”? With the Prism rig?

Craig: Showco Prism uses a lot of “beam steering.” Jim Brawley, who was heavily involved in its design, is extremely knowledgeable.

Michael:
Do you have an engineering degree in acoustics? Just curious. [i.e. what does it take to be a design consultant?]

Craig: Oh boy, great question. Actually I trained and studied to be a mechanical engineer in an oil refinery. Just spent a lot of years gettting mad that I could hear things with arrays and not predict them. Kept asking questions until I started to get an understanding. Still a bunch to learn though.

Tucci: Have you successfully used the directional subs from Meyer?

Craig: No, I have not used the Meyer subs, although I look forward to a client who has enough money…Actually it is a cool piece of gear. It is relatively simple to achieve the same thing with two separate boxes and a basic DSP. Same as the techniques for cardioid mics.

Charles: With regards to beam steering, are there any “rule of thumb” ways for alleviating the “power alley” effect?

Craig: By power alley I assume that you mean the LF build-up in the center of the room…right?

Charles: Correct.

Craig: To reduce “power alley” we have to have horizontal directional control at LF. Difficult to do unless the array is large. Possible but complex.

Also RE power alley reduction we need asymetrical horizontal pattern control of the array with LF angled off stage considerably and HF and mids unaffected. Tricky. Steering subs is much easier by simply adding delay to the outer subs and “decorrelating” the summation down the center line.

Moderator: Would it be possible with, say, 8 boxes?

Craig: What 8 boxes? (product?)

Moderator: Any box with 2 front-loaded woofers.

Craig: Assuming 8 (dual 15” vertical placed) boxes a side horizontally placed, then you would get substantial horizontal inconsistency in LF performance. This could be mitigated by frequency shading the outer drivers but then you would lose LF output. You can test this out by down loading the EV Array Show program from the EV site. It’s free and a great education.

Weogo Reed: What about simply placing all subs on one side of the stage? Get rid of power alley and have a little more volume on one side and lower on the other?

Craig: Putting subs to one side would sound pretty weird, I think. Rather steer the beam a little.

yamama3000: If subs are ground stacked you get a +3-6 dB through coupling…is the 6 dB drop part of this equation?

Craig: No, the 3 dB (half-space loading) does not affect the horizontal null at all. You would get the same result with the subs in the air. (Keeping in mind that the stage position would then be asymmetrical to the array null.)

Tucci: To get the subs decorrelated, how much phase change/time are you talking about? You’d want the outer subs to show up “late” at the center line. That could be a significant amount of time, no?

Craig: Time and wavelength are simply two sides of the same coin. The wavelength at 60 Hz is around 16 feet, so if you added 4-6ms of delay you would get significant beam steering.

yamama3000: To the outer boxes only…correct?

Craig: Yes, the outer boxes only. Of course if you wanted to impress the guest engineer, you could align all of the time to point subs at the mix location…

Denny Strauser: What proportion of boxes must be delayed for effective steering?

Craig: Impossible to answer without more info as to the number of boxes, size of boxes, etc.

Tucci: How about doing it the inexpensive way? If 4 ms is 90 degrees at 60 Hz, why not just turn the outer sub at a right angle?? Clever eh?

Craig: Tucci, you jest of course….

Tucci: Yes, of course.

yamama3000: And to add to Denny’s question: Will Smaart help in the equation?

Craig: Smaart will only help you to tell what the result of predictions are, not do any predictions itself. Good to know that what you tried worked, or not of course, and then Smaart is a great tool.

Weogo Reed: Going back to the all-subs-in-one-place theme, do you ever use all subs at the front of the stage?

Craig:
Yes we do use subs on the floor in front of the stage. However we almost always spread them out so that we get an infinite line array, thus losing only 3 dB per doubling of distance instead of 6 dB.

David Gunness: I have to go to bed now (early flight), but I wanted to say “hi” and “nice job”!

Craig: Oh boy, if I knew Dave (horn dog) was on the session I would have felt much more intimidated…

yamama3000: Explain “horn dog.”

Craig: Dave designs horns and other things, and is also the author of the FChart program.

Moderator: Dave Gunness will be our guest here next Monday night.

Craig: Dave has more knowledge about array “beam steering” than anyone I have ever met. I’ve met a lot of really good engineers.

Dale Shirk: Craig, when you roll off upper frequencies on the outer drivers of a line to shorten it, what is the affect of the phase shift (group delay) of the HPF in the passband of those drivers? Do the center drivers need wide-band delay to match?

Craig: In general the filters are pretty shallow and the delays are not too bad as long as you know what it is you are doing. If the shading is symetrical then it is easy to correct the delays.

Tucci: Would that not be a LPF, Dale?

Craig: No, Dale is right, it’s a HPF.

Weogo Reed: Cool. Do you do any shading to make coverage more even?

Craig: Yup, we shade just about all of our clusters in one way or another. This shading thing is really no great mystery really although audio gods like me try to use as many big words as possible to that people will not realize how easy it actually is.

lilbob: Do you have a favorite subwoofer in general?

Craig: The two most frustrating things in my audio life is getting great sub sounds and getting a great piano sound… I currently use a lot of the Bag End ELF subs and considering trying those in conjunction with EAW horn-loaded subs. The Bag Ends have great extended lows and the EAW’s have great “punch”...

yamama3000: What do you think about the use of extended bass frequencies like the Servodrives?

Craig: I am not personally a fan of the Servodrive sound. I have friends who like it a lot though.

yamama3000: Why?

Craig:
One of my personal sub tests is to hear a bass guitarist with a five string bass scale down to an open “D” string. I want to hear distinct pitch changes. My tests with Servodrive did not seem to give great definition in my opinion. I don’t want to use this forum as a negative for any product though.

Michael: Why does one Prism rig sound beautiful and even and another sound gak nasty? Operator error?

Craig: Lots of reasons why one show sounds different to another. Mix engineer, system engineer set up, sucky poo band (a technical term), bad acoustics.

Michael: Have you used HLA sub?

Craig: I have not used the HLA sub itself but have used the same JBL driver in similar box constructions and porting. It is a good 18” sub.

miffe: Which one of the HLA sub drivers? DCD or the older Super Vented Gap?

Craig: Older Super Vented Gap.

Denny Strauser: Are the Bag End subs capable of doing large shows? (Indoor arenas & sheds)

Craig: Sure. Just remember that they are a sealed box and thus do not have the efficiency of a port. In larger arrays this becomes less of an issue, though. Ground loading helps greatly as well. The efficiency of a sealed box allows you to get a huge number of drivers in a given space. Lots of good approaches to subs.

Van Metschke: I was quite impressed with the Bag End sub you showed me in Dallas.

Craig: Hi Van! Call me tomorrow, I have an answer to your Yamaha question.

Charles: On a slightly different topic, do you find yourself installing more LCR (left-center-right) systems today than stereo systems? If so, why? Is it a specific client request or your suggestion?

Craig: We do a lot of LCR systems because many of our clients are large churches where both music (best supported by stereo) and speech (best supported by center cluster) are needed. I personally really like to mix on a true LCR system as it provides a lot more opportunity to “image” the sound and pull the lead vocal out of the mix.

yamama3000: Then the need for a LCR console or center off a matrice?

Craig: Mixing an LCR system with a LR console is a pain in the butt. I like what Midas has done with the proportional mix split approach to LCR. Allen & Heath does a similar thing on its LCR boards.

yamama3000: Vocal OUT of the mix? You mean IN, right??

Craig: Sorry - I mean the vocal jumps “out” at you.

lilbob: How do you deal with coverage issues with vocal only in a center cluster?

Craig: Each cluster must cover all of the room ...or the signal from the center must be matrixed to the outer firing cabinets of the LR clusters. The latter is the more common.

yamama3000: How much mixing do you get to do these days?

Craig: I still mix on contract once in a while. Often mix the opening event of our projects. I’m a better designer than mixer though….

lilbob: Do you spec a broader coverage array in the center?

Craig: Yup, sometimes the center coverage is a little wider. It really depends on the seating configuration and how much of a thrust stage there is.

Scott R: Where do you like reverb (on the vocal) on a LCR? C, LR, or both?

Craig: For solo vocal I like to place it in the center and pan verb to LR. Depends on song though.

lilbob: I’m confused a little about each cluster covering “all of the room” as it relates to LCR imaging. Would you perhaps have center channel cabinet(s) in the L & R clusters to complete the coverage?

Craig: A true LCR system must allow you to pan say the SAT (sop-left, alto-cent, tenor-right) you should have a stable mix balance anywhere in the room. Thus each cluster must cover most of the room. We often use cabinets within the LR clusters to feeed center signal to. These are not separate cabinets, but cabinets (usually off stage cabinet) fed with a mix of C and L (or R if right cluster).

Michael: Do you notice any difference in result with dual-coil drive speakers? Do you think speakers with two voice coils will be developed on a broader basis than at present?

Craig: To be honest, I have not paid a lot of attention to the make up of the driver units. I work extensively with the specifications of the unit. Can’t answer your question as well as I would like too…

Moderator: Craig, what are your views of the advantages/limitations of powered speakers?

Craig: Powered speakers have the great advantage of a controlled signal to the speakers. Best use is in portable applications. In permanent, it is tricky and often expensive to get power to the clusters. Also maintenance on high clusters in interesting if the amps are up there…

yamama3000: Do you agree that the quality of glues used in speaker manufacturing makes for a more reliable driver?

Craig: I ain’t a glue guy. Have no idea…. All of the main manufacturers are very good at driver design and I trust that they are using the best adhesives. As to music-store grade stuff…who knows?

Angus-Young: What do you think of sonic maximizers or exciters made by BBE or etc? Do any of the big sound companies use them?

Craig: I can’t really say what everyone uses. I have not ever seen one on the main system of any touring rig… Sometimes, not very often you will see them in a rack. I personally don’t like them in a well-designed rig.

Moderator: We’ve got time for a couple more questions.

lilbob: Thanks. Any venues asking for surround or 5.1 installs?

Craig: We often use surround sound effects speakers, but not in the formal 5:1 that you refer to. It’s really up to the sound designer of the show.

Ken: I noticed in one of recent baseball stadium designs, you placed a center point-source system in center field, and 2 banks of effects speakers to the left and right. What is the exact purpose of these effects speakers?

Craig: You are referring to the Dodgers Stadium rig, I assume. We are intending to use the LR arrays (6 by MSL-4s each) for feeds from the “Click Effects” computer. Definitely not vocals or this instance music, due to limited output of the LR arrays.

lilbob: Any single piece of live gear that really impresses you?

Craig: I think that the new Yamaha PM1D is going to revolutionize the industry. I think that Peavey MediaMatrix did that last decade.

Moderator: lilbob’s will be the last question of the evening.

dave: On behalf of the folks here at ProSoundWeb.com, I’d like to thank you, Craig!

Craig: Great fun. Hope others enjoyed as much as I did!

dave: I’d also like to thank all of those that stopped by as well.

Moderator: Throw microphones!
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{extended}
Posted by Keith Clark on 05/23 at 05:31 PM
AVFeatureBlogStudy HallAVLoudspeakerMeasurementSound ReinforcementSubwooferPermalink

Install Your Own Church Sound System? Here Are Some Cautionary Tales

It isn't exactly rocket science, but you need to do your homework
This article is provided by Church Soundcheck

Audio consultants often find themselves working with people in churches who seem eternally bent on saving money at any cost. This is the kind of church that will call with the seemingly innocent request to have the consultant design a new sound system for them. At some point in the conversation they’ll add that they want to do the installation themselves.

That approach can be a mixed blessing both for the consultant and for the church. On the one hand, at least they’re using a consultant’s seasoned advice to make the best choices of gear for them to use. The problem starts when they begin to think that the process of actually installing the gear isn’t all that difficult.

Momentary Lapses of Intelligence
Here are some textbook cases. In order to protect the innocent, I’ll use their real names.

So one day my friend Warren calls me and announces that his church is ready to renovate their existing sound system, and they want to do it right this time. He invites me to meet with their sound committee, and within a few days I’ve got the project to design the system.

In order to save money, the church plans to use volunteers to run all the wire, hang the loudspeakers, and wire up the sound booth gear. I insisted on wiring up the amplifier rack myself, to be a friend, save them the work, and me the headache of possibly having to fix it later.

A couple of months later the equipment is all sitting at the church, and the troops are ready to proceed with the install. So I arrive with TEF and solder station in hand ready to talk them through the install.

Now right off the bat, I’m scared by what I see. To free myself from any liability in the future, I do what every good consultant does - I don’t give them any advice at all about how to hang the loudspeakers in a safe manner. That’s really the job of the sound contractor.

They assure me that they’ve researched their hanging method carefully, and at my insistence have even had a structural engineer sign off on their solution, but I make a mental note to not find myself standing under the cluster for any length of time.

After a lot of scraped knuckles, sweat, grunts and groans, the loudspeaker wire, microphone snakes and return lines are finally pulled into place. At around 1 am on the third day of the installation, we finally light up the system and start to voice it.

By this time, everyone is toast. I’m so tired I can hardly see straight, let alone hear really well. The volunteer crew is absolutely wiped out, but we’re so close now that they’re not about to leave without hearing the system lit up for the first time, so they’re napping on the pews while I continue to work.

To their credit, there were no polarity reversals anywhere in the system. Bless God, somebody was paying attention.

Don’t get me wrong. The church loves their new sound system. And I’m sure the crew has good memories of the time they invested on that project.

But by the end of the project everyone was wiped out, stressed out, on the verge of being mad at everyone, and just plain in a bad mood.

More Angst
I recently finished another project like this. My friend Duane had his best “ain’t no way on earth that’ll happen” look on his face when he considered the idea of using a sound contractor to do their installation.

So I designed the system, gave them a shopping list, and answered a myriad of questions as the project went from a few pieces of paper to loudspeakers hanging somewhat precariously from the steel.

Here again, the weakness seems to come in not knowing precisely how to safely hang really heavy loudspeakers over people’s heads. Hanging heavy loudspeakers isn’t easy in the first place. Getting them aimed precisely where they need to be aimed is an additional challenge.

But when I saw the loudspeakers hanging from S-hooks and swing-set chain, I knew they had ignored my urging to buy their hardware from a professional rigging supplier. They didn’t have a smile on their face when I insisted that they replace the chain and hardware with the real stuff. And don’t even get me started on the points they wanted to hang the boxes from.

Part of the angst of Duane’s project came through the scheduling. All involved wanted the system to be in place in time for their Easter pageant. Flying the loudspeakers meant having to move scaffolding into the room in order to pull wire and hang loudspeakers.

During the same time frame, the drama and music team needed access to the stage for their pageant rehearsals several evenings each week, so having scaffolding on the stage was a problem. Just try sharing a stage with those two groups.

The installers had to remove the scaffolding and all of their stuff each evening so that the pageant rehearsals could continue as scheduled. That process added undue pressure on the volunteer sound installers.

You wouldn’t make the same mistake?! I’m sure that’s what Duane felt. Happened anyway. Nobody lost their salvation over it, but it’s certainly something they wouldn’t do on purpose again.

Before I continue, please understand. The guys that find themselves in these predicaments aren’t dolts. They’re bright, sharp, astute, focused, detail-type personalities.

But by the time they realize that they’re in over their heads, it’s too late to drop back and do anything else about it. They’ve got to see it through and get on with life.

So what makes such a rational, educated person think that they can install a sound system just as well as a seasoned sound contractor? Contractors have years of hard-won experience they can draw upon every time they hang a loudspeaker or wire up a rack.

As well meaning as they are, churches who set out to do this work on their own are in no better position than that sound contractor on his very first install.

I talked recently with my new friend, Rod, who was just then receiving the equipment that I specified and he ordered. His conversation with me then was filled with the usual confidence that both Duane and Warren shared in their first dialogs with me.

Rod was certain that he could have the cluster in the air and ready to get sound out of it within the next couple of weeks. I tried my best to cool his optimism while still being encouraging. I knew that if his experience was anything like most of the others, he’d be in for a real surprise!

Well, I just spent this past weekend commissioning the sound system that I designed and that Rod and friends installed. I called him last Thursday night before I left to make sure that he was really, truly ready for me to be there, and he assured me that all would be fine.

When I arrived in his town, I called again and his response was, “Well, we’ll be ready, but don’t hurry over here.” As I walked into the church, he had just finished making the final connections in the amp rack. To their credit, our system voicing process wasn’t delayed.

Rod finally realized - just like Warren, and Duane, and others have - that installing a sound system properly isn’t as simple or as easy as many want to think early on in the process.

Yeah, But ...
Look, I know your church is different. I know y’all won’t make the same mistakes that most other churches make during this process. And I know your church will end up with an award-winning sound system that will make every sound contractor green with envy.

But just humor me. Tell me you’re at least going to consider hiring a first rate sound contractor for your next system installation. It’ll make me feel better.

For what it’s worth, I also know that there are some contractors out there who shouldn’t be in business. Frankly, you probably could do the work better than some sound contractors out there.

Even though we’re not professional painters, I think that my wife and I do a more careful job of painting our house simply because it’s our house - we live there every day and care about it more than your typical painting contractor would.

But as much as I know about electricity and electronics, I’m not going to volunteer to wire our next house. I might do some extra stuff - like putting lights in the closets, adding phone outlets in all of the rooms, and so on. But I’m not interested in doing the entire job myself.

While installing a sound system isn’t exactly rocket science, it is more complex than painting one’s house. That’s one reason why you need to do your homework on the contractors you’re considering.

Please at least seriously think through all of the realities before you let your church go off the deep end in their eagerness to simply save some money. They may save a few dollars during the installation, but the toll that the process exacts from the church’s volunteers may not be worth it in the long run.

People are more important than money. And it may be that later on y’all will find yourselves doing the work all over again.

A Quiet Voice of Reason
Now, don’t go around telling everyone that Curt said that no church should install their own sound system. I didn’t say that. All I hope to offer here is a voice of reason in your eager pursuit to save a couple of bucks.

If you’re thinking about installing your own sound system, please determine now that you will sort through every possible issue. Develop a contingency plan for all of the things that are going to go differently than you plan, because they will. Step back and think it through before your eagerness gets the best of you.

For example, what are you going to do when the input panels for the floor pockets don’t come in with the connectors laid out the way you told them to? What are you going to do when you discover - after the scaffolding and scissor lift are long gone - that you hung the cluster two feet higher than it should have been?

What are you going to do when the mic snake you ordered arrives with totally the wrong connectors? What are you going to do when your consultant discovers through his acoustical testing that two of your four main loudspeakers have their woofers wired out of polarity - that they came that way from the loudspeaker manufacturer!?!

No, really. Tell me what you’re going to do. Because if you’re installing the sound system yourself, you ARE the sound contractor. It’s your job to make sure the installation and every device in the project is working correctly and installed properly.

And if you’re like most churches, you’re not only installing the sound system, you’re also installing the video system, and the stage lighting system, and… The size of the task can mushroom beyond your wildest expectations in no time.

I assume you’ll be trying to accomplish this task while gainfully employed in another job, so your installation efforts will be done in the evenings and on weekends. You’ll probably need to take vacation time during the last few days of the project when everything comes together.

And I assume that, if you can find volunteers as eager to help you as you are to take on this project, that they too will be there whenever they can. Be prepared to discover that their available times might not be the same times as you plan to work, or nearly as often.

Do your best to step away from the project long enough to see the big picture and what the process is going to do to you, to your life, to your family, to your friends who are going to help you get this job done, and to your church.

The church as a whole has enough people who have been burned out or hurt emotionally through their service to their local church. We don’t need to add any new people to that list.

Uncle, Uncle
Okay, I’ve beat you up enough. If after all of this you’re still convinced that you need to do the install yourself, get prayed up and go for it. As long as you know up front that it’s not as easy as you think it will be.

The reality is that there can be tremendous value to having church staff and/or volunteers install their own sound system. More important than the money you’ll save is the fact that they’ll emotionally take ownership of the system more quickly.

Also, if anything ever goes wrong with the system - and we both know that will be discovered on Sunday morning before the service - your volunteers will know where every piece of equipment and scrap of wire is in the entire facility, and how it’s hooked up.

They may even be able to track down the problem and fix it before the service instead of sometime later next week when the sound contractor’s audio technician can schedule an appointment. That works of course until the folks that did the install get relocated by their job, or move to another church for some reason.

Remember that, whatever happens, God is still on the throne. So have fun. Or else.

Curt Taipale heads up Church Soundcheck, a thriving community dedicated to helping technical worship personnel, and he also provides expert systems design and consulting services with Taipale Media Systems.

 

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Posted by Keith Clark on 05/23 at 03:29 PM
Church SoundFeatureBlogStudy HallBusinessEngineerInstallationSystemTechnicianPermalink

Pro Production: The Essentials Of Automated Lighting Design

Capabilities are greater, possibilities are limitless, and results are more spectacular

We eat light, drink it in through our skins. With a little more exposure to light, you feel part of things physically. I like feeling the power of light and space physically because then you can order it materially. Seeing is a very sensuous act; there’s a sweet deliciousness to feeling yourself see something. — James Turrell, artist known for his use of light in art

Designing with automated lighting is really not much different than designing with conventional fixtures. The same design goals typically apply, the techniques are very similar if not the same, and the results, if the designer has met the goals of the design, can be similar. The difference is that the capabilities are greater, the possibilities virtually limitless, and the results can be more spectacular.

The flip side of the coin is that indiscriminate use of automated lighting can be utterly disastrous. Since automated lighting first became commercially available, the same adage about using automated lights or some variation of it has been uttered many times.

The way Anne Militello of Vortex Lighting expressed it was: “Just because it can move doesn’t mean that it has to move.”

The corollary to that might be that all movement and color change isn’t necessarily good; use them with purpose and discretion.

Design Goals
No one would begin a journey without first knowing where they want to go. The same applies to lighting design. Before beginning a new lighting design project, you should know exactly what your goals and objectives are and how you’re going to achieve them.

Before ever putting pen to paper or laying out a plot you should have a list of priorities. Some of the more common lighting design criteria are outlined in the following sections.

Visibility
Visibility is one of the most important goals of a lighting design. If you’re lighting a stage with a band or an actor, then the subject(s) should be illuminated sufficiently for the audience to see (Figure 1).

Figure 1: One of the most important elements of lighting design is visibility. (Bruce Springsteen 2009; Lighting design by Jeff Ravitz.)

In some instances facial features and expressions are very important and in other instances the designer may choose not to reveal too much about the subject. Visibility should be quantified in terms of illuminance in lux or foot-candles (fc).

Focusing Attention
During the course of a show, it’s natural for people’s attention to drift. By keeping the stage and the subjects on it well-lit and keeping the peripheral areas at lower illuminance levels, more attention will be focused on the subjects (Figure 2).

Focusing attention is as much a function of lighting contrast, or the difference in illumination levels between the areas of interest and the areas of less importance, as it is a function of overall illuminance levels.

Figure 2: A lighting system can help compel the eye to stay focused on the subject by illuminating it more than its surroundings. (Bruce Springsteen 2009; Lighting design by Jeff Ravitz.)

If everything in a space is lit to 300 fc, the eye has no focal point and there’s nothing to draw the eye or compel it to stay focused on the subject.

If, on the other hand, the subject is lit to 150 fc and the rest of the room is lit to 25 fc, then the eye is more likely to stay focused on the well-lit subject rather than wander around a darker room.

Many shows are reinforced with live video, either in the form of image-magnification (I-mag) or “B roll,” which is pre-produced content for playback (Figure 3). If the show you’re lighting has video, then the lighting requirements could change dramatically.

The light levels, uniformity, color temperature, and direction of lighting are all subject to critique and debate by the video crew. It’s best to communicate with the video director before beginning the lighting design to find out their requirements and expectations.

Figure 3: Video is an important part of many productions. Lighting plays an important role in video acquisition and it changes some of the criteria for lighting design. (Bruce Springsteen 2009; Lighting design by Jeff Ravitz.)

Find out about their expectations for light levels on the subject and on the set.

Modern video cameras are capable of producing good results with lower light levels but higher lighting levels still produce less grain in the picture. One of the biggest issues to deal with when video is involved is the uniformity of light across the stage, particularly if the subject moves around a lot or if there are many subjects spread across the stage.

If the light level varies from subject to subject or from one position to the next on stage, the video engineer will have to “ride the iris” or “shade the cameras” to correct the exposure levels every time the camera moves and chances are they won’t be happy about it.

Modeling
One of the main objectives of lighting design is to give form and definition to the subject by “modeling” it with light. That simply means to accentuate the shape, texture, and form of a subject by lighting it from different angles and carefully controlling the intensity of the various lights to reveal information about the subject.

Lighting an object only from the front tends to make it look flat and two-dimensional. It does little to give the subject definition and depth and bring out the features of the subject.

A video camera tends to accentuate shadows and sometimes they can make them look unnatural. A video camera also has the ability to zoom tightly on the subject and magnify the intensity of shadows. For those reasons, a lighting designer might choose to light a subject more flatly if video is involved.

But if we’re lighting primarily for an audience, then we can model the subject, illuminate its distinguishing characteristics, and make it look more natural from a distance.

Creating Depth
Lighting can also create depth and give the appearance of space. By controlling the intensity of the foreground, mid-ground, and background, we can give the stage spatial reference and definition. This prevents objects and people from looking as if they’re on top of each other or right next to each other.

We can also create depth by using backlight to highlight the form and shape of a subject.

Aesthetics And Mood
By using color, patterns, and projections, we can change the aesthetics and influence the mood of the audience (Figure 4). This is one of the areas where automated lighting excels. It can be bright and cheery, dark and moody, or simply paint a picture with an interesting aesthetic appeal.

Figure 4: A major factor in many lighting designs is to create an aesthetically pleasing look. (Chris Tomlin 2009; lighting design by Jon Weir and photo by Shann Swift.)

Although any two people may or may not agree on what’s “aesthetically pleasing,” there are certain guiding principles. For example, the combination of blue and yellow creates a strong contrast. There are many other principles of colors and color combinations that are very useful as a starting point in lighting and scenic design.

Most lighting design is a combination of some or all of these objectives. The job of the lighting designer is to prioritize the goals of the project and make the best use of the tools to meet those objectives. In the end, the final result is often a compromise between what’s desired and what’s possible given the technology, expertise, creativity, and budget.

Once the design goals are decided, the task of laying out a lighting plot to meet those goals comes next. Any or all of these goals can be met using a three- or four-point lighting system.

Three-Point Lighting
A three-point lighting system uses three lights to illuminate each “acting area” on a stage.

Figure 5: A grid of acting areas helps to define placement of key, fill, and back lights.

An acting area is a section of the stage, typically 8 to 10 ft 2 (2.5 to 3 m 2 ) delineated by the lighting designer for the purpose of breaking down the task of lighting the stage into smaller areas with better control over the illuminance of a subject and the foreground, mid-ground, and background (Figure 5).

A lighting plot typically begins with a scale drawing of the stage and/or space in which the production will take place. By marking off a grid on the drawing of the stage, the designer can treat each of the acting areas to be lit as a single entity.

The three lights that light each acting area include the key light, fill light, and back light. The key light is the strongest light of the three and it represents the dominant source of light such as the sun or artifi cial light in a room.

In a three-point lighting system the key light is located 45 degrees above the horizon and 45 degrees to the left of the center line (as seen from the stage – Figure 6).

Figure 6: Three-point lighting system: (clockwise from top left) plan view, side elevation, front elevation, and render window.

The purpose of the key light is to provide visibility and to model the subject. The 45-degree angles provide enough shadow to help define the characteristics of the subject such as the nose, chin, and eye sockets.

The fill light is also located 45 degrees above the horizon and 45 degrees to the right of the center line. Its purpose is to help ameliorate the intensity of the shadows produced by the key light and control the contrast between light and dark. By adjusting the intensity of the fill light the depth of the shadows can be controlled and the amount of modeling can be adjusted.

The back light should be located directly behind the subject or acting area and it can be anywhere from 45 to 60 degrees or more above the horizon.

The purpose of the back light is to bring out the shape of the subject and create depth.

If the luminaire/lens combination for each lighting position is carefully chosen and the plot is carefully constructed, then the peak illumination at the center of the beam will correspond with the center of each acting area, and the adjacent beams will overlap at 50 percent of the center beam intensity.

The point in the beam profile where the intensity is 50 percent of the peak is defined as the edge of the “beam” (Figure 7). The angle of the beam, therefore, is defined by the two points in the beam profile where the intensity is 50 percent of the peak.

The beam angle is often given in the literature provided by the manufacturer or can be found in the specifi cations of the fixture online.

When two adjacent fixtures overlap at the edge of the beam, it should result in approximately the same illuminance where the two beams overlap as the center of a single beam because 2 x 50% = 100%.

But it requires that the selection of lenses provides the right beam width at the throw distance chosen by the designer and meets the illuminance target of the design.

After the key, fill, and back lights are selected and properly placed, the set can be duplicated for every acting area.

Figure 7: The angle at which the intensity falls off 50 percent from the center peak intensity is defined as the “beam angle” of a fixture.

If the design is carried out properly, then at least three things will be accomplished: (1) the light level anywhere on the stage will be high enough to create good visibility, (2) the lighting across the entire stage from stage right to stage left and from downstage to upstage will be relatively uniform, and (3) the lighting designer will have complete control over which acting areas can be lit or unlit.

The key lights and fill lights should be soft-edge fixtures like a Fresnel or a PC spot so that when they overlap with the adjacent key and fill light, respectively, they will blend well. The profile of a fixture is the cross-sectional plot of light intensity. When the profile is peaked and looks like half of a cosine wave form then the fixture has a “cosine beam profile.”

Two fixtures with a cosine beam profile will produce maximum uniformity when they overlap at the point in the beam profile where the intensity is 50 percent of the peak (Figure 8). A cosine beam profile is sometimes referred to as a blending distribution.

Figure 8: Two cosine distributed beams overlapping at the 50 percent drop-off. A “cosine distribution” or “mixing distribution” has a peaked beam profile, which, when overlapped at the 50 percent drop-off with a like fixture, produces the most uniform wash between the beams.

It’s important that there should be some means of controlling light spill to keep stray light off of set pieces, walls, the fascia of the stage, video display surfaces, the cyc, and any other surface that shouldn’t be lit by the stage wash. Some automated lights have motorized barn doors or framing shutters that can be used for that purpose.

Toning A Three-Point Lighting System
In a three-point lighting system, the subject is typically lit with a warm/cool color contrast. The key light can be warm or cool light and the fill light should be the opposite of the key light.

The amount of color depends on the application. For a live audience the color contrast can be stronger, but video and I-mag strong contrast on opposite sides of a subject’s face can look peculiar.

Multi-Point Lighting
If a production involves the use of video or film, a three-point lighting system may produce too much contrast between the light and dark areas. In those instances a four-point or a multi-point lighting system, sometimes called a jewel lighting system, may produce better results.

In a four-point lighting system, the key light is moved directly in front of the subject and two fill lights are placed on either side of the subject. The back light remains in the same position as in the three-point lighting system (Figure 9).

Figure 9: Four-point lighting system: (clockwise from top left) plan view, side elevation, front elevation, render window.

Because the key light, which is a front light, projects directly onto the subject, it looks flat to the human eye, making it harder to distinguish features. But to the camera it looks more natural by de-emphasizing the shadows on the face.

In a concert touring system, the key light is typically provided by followspots. Many times there are at least two followspots for each band member, so the lighting is often a five-point system. If there are no followspots available, then the front light or key light is often provided by Fresnels, PAR cans, or Lekos, since they’re much more affordable compared to automated lighting.

The exceptions are when the cost of labor is very high, as in a convention space, or when time is very short.

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Go here to acquire Automated Lighting, 2nd Edition, published by Focal Press. Use the promo code FOC20 during checkout to receive a 20 percent discount.

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Richard Cadena is the technical editor for PLASA, an authorized WYSIWYG trainer, and 20-year veteran of the entertainment lighting industry including stints with two of the world’s largest automated lighting manufacturers. He has a background in electrical engineering and electronics, and he is a freelance lighting designer with a portfolio of several major lighting designs and installations and is proficient in WYSIWYG, LD Assistant, and Vectorworks.

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Posted by Keith Clark on 05/23 at 02:34 PM
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Pro Production: Mounting Projectors Above Or Below The Center Of The Screen

There are two techniques that deliver this installation flexibility.

Today’s projection technology provides tremendous flexibility for locating the projector with respect to the screen. There are two techniques, applied individually or in combination, that deliver this installation flexibility.

They are:

1) Lens Shift
2) Electronic Keystone Correction

For Lens Shift, the primary enabling component is the projection lens. The physics of a convex lens dictate that an accurately focused image exiting the front of a lens will “shift,” based on the introduction of vertical or horizontal movement of the focused image entering the back of the lens.

In the projector world, this means that if the lens is moved up or down with respect to the source generating the focused image, the fully focused and geometrically correct image also moves up or down on the screen.

With good quality lenses, shifted images still demonstrate excellent geometry and focus over the full lens shift range. The limits of acceptable lens shift are dependant on the size of the image (light patch) entering the primary side of the lens, and the overall aperture of the lens.

If the primary side of the lens is very large and the light patch produced by the prism is very small, a large amount of lens shift will be available. If it is a large light patch, larger lenses are required and generally, lens shift is more limited. Extreme short throw lenses usually have limited lens shift as well.

When applying lens shift, the light patch can actually be viewed as it moves on the front surface of the projection lens. As the corners of the light patch begin to encroach on the edge of the lens, the image will appear to lose luminance in that area. This is called “vignetting.”

Many projectors with lens shift capability are designed with mechanical limits to prevent the lens from being shifted to the point of objectionable image vignetting.

For efficiency, most projectors with lens shift are designed to provide more “up” lens shift than “down” lens shift. This optimizes projector flexibility for the vast majority of applications.

As an example, 50 percent lens-shift up, with only 20 percent lens-shift down, is not uncommon. Although the total shift range is limited, the user still has full lens shift available if shooting from a pedestal at the bottom of the screen, or if shooting ceiling mounted from the top of the screen with the projector inverted.

If your application requires more image shift than is provided by lens shift alone, you will need to consider tilting the projector and applying electronic correction to compensate for the resulting optical “keystone” of the image.

Most projectors include electronic keystone correction. If electronic keystone is not a feature of your projector, an external image “warp” processor can be employed to achieve the same result.

Be advised, whether internal or external to the projector, electronic keystone only corrects for geometry distortion and does not compensate for focus irregularities produced by steep projection angles or irregular projection surfaces.

There is no rule as to how much keystone correction is acceptable - it is dependent on the image content, the viewing distance and user opinions. As an example, applying 5 percent electronic keystone correction may produce acceptable results for video viewing, but chances are, it would not be suitable for high-resolution data.

It is also worth noting, the longer the throw distance, the more the projector can be offset without requiring dramatic use of electronic keystone correction.

If you know your application will require more image shift than the lens shift provided by the projector, create a scale mock-up of the installation. Be sure to use the same projector type, lens, relative throw-distance and projector-to-screen relationship (offset), as will exist in the final application.

First apply maximum lens shift, followed by tilting the projector until the image lands on the screen. Next, dial in the keystone correction as necessary. Lastly, review content that is relevant to the application, and whenever possible, let your customer be the judge.

If the conclusion is that electronic keystone correction does not produce an acceptable result for the content to be displayed, the application will need to be redesigned such that the projector-to-screen relationship is within the lens shift capabilities of the projector and lens you are employing. Alternatively, you can consider specifying a projector with a broader lens shift range.

This article provided by Digital Projection.

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Posted by Keith Clark on 05/23 at 12:00 PM
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Church Sound: Of All The Knobs On The Console, This One Is The Key…

Getting this right just makes your day go so much easier
This article is provided by ChurchTechArts.

 
A typical mixing console may have dozens, even hundreds of knobs and buttons and faders.

Each one has a specific function, but one is more important than all the rest. It’s typically at the top of the channel strips and it’s called “gain” (or sometimes “trim”), and it’s perhaps the most misused and misunderstood control on the whole board.

Get it set wrong and no amount of fading, EQ or outboard processing will fix it. Get it right and the rest of your mix will come together much, much easier.

So, how do you get it right? Well, it depends. (Great - thanks Mike!) Seriously, it depends—on your board. I wish I could tell you to turn the gain up until you get to 0, then you’re done. That may work, but it may not be optimal.

You have to do some experimenting and listening. Follow along and I’ll walk you through the process, then we’ll look at some specific things to listen for.

For starters, adjusting gain needs to be done in a methodical manner. If you’ve ever been to a concert early and watched a sound check, you’ve seen how it’s done. Turn down all of the faders on the board, and start with the gains all the way counter-clockwise. Start with one instrument, say the kick drum.

Ask the drummer to kick, kick, kick, kick. He keeps going until you tell him to move on. If your board has a PFL or Solo button on the channel, push it for the kick drum (or whatever you’re starting with). The PFL should route that channel to your main meters (check your manual), so keep your eye on it and gradually bring the gain up.

When it starts to peak around 0, you are close. Now you can start bringing up the monitors, and then house fader.

Repeat this process with all the other instruments on stage. Then move on to vocals. (We’ll deal with some more suggestions for a sound check in another post.) You should now have all the instruments and vocals hitting 0 or a little more. At this point, you may be done. Or not.

It all depends on your board. Some boards have a lot more headroom than others, and if you cap the levels at 0, you are not fully utilizing all the gain they have available, and are not maximizing your signal to noise ratio (the difference in signal level between the noise floor and the signal or music).

Other boards are pretty much spent at 0, and if you send 10-16 channels all at 0 to the main bus, it will overload and you will distortion. Or you may just be on the verge of clipping all the time.

This is where you need to listen and pay attention to your board. The console we have at our church will take +8 inputs all day long, mixed into groups and to the mains with no hints of saturation or distortion. So we can run stuff hot, and maximize our signal to noise ratio.

On the other hand, I once used a console at another church that would be completely out of headroom if you ran all the inputs at 0.

Play with your board, try different levels and once you settle on a level that works, stick to it. Make it systematic so everyone uses the same gain structure.

Once it’s repeatable, you’ll have better, more consistent sound every week.

This weekend I was reminded of another gain setting that is just about equally important (perhaps even more so), and that would the gain on the wireless mic the pastor is using. Here’s what happened.

I’ve been in the process of revamping our entire wireless mic family over last few months. The new mics have been really great.

The challenge is that we have some speakers (people talking) who like the new mics, and one (turns out he’s the new senior pastor) who doesn’t so much. Since he’s new, I’m cutting him some slack and letting him use a lav (for now…).

And that’s the rub. We have one bodypack that is “assigned” to the speaker for the weekend. Sometimes we’ll plug in a lav, other times a different model, and each mic has a different sensitivity rating; some speakers are loud, others are quiet.

If you read the first part of this article carefully, you know where this is going. Just like the input gain on your console, the bodypack also has an input gain setting (at least it should – if it doesn’t go order a new one that does).

Sometimes it’s a rather coarse “0”, “-10” switch; other times it’s a little control in the battery compartment that needs a tweaker; and yet other times, it’s a handy thumbwheel on the side of the transmitter.

The problem is that too often we sound engineers get so busy, we jack in a mic, drop in a battery and hand it to the speaker who is already running to the stage for a sound check. We crank up the gain on the board as he says, “Check one, two…are we done?” and hope for the best.

It’s not until he’s up on stage at the beginning of the message that you hear the familiar crackle of some sound gremlins having a bad day. You check your console gain, everything is fine; you may even check the compressor, the EQ and everything else.

Check the wireless receiver. If it’s a good one, it will have an audio level meter. A less good one will have a clip light. If you see clipping, or the meter is maxed out, you’re in a world of hurt. You’ve gone and done it – you’ve used up all the headroom in that little bodypack.

And it’s not like you can run up on stage during the message, reach into the pastor’s back pocked, grab the mic and tweak the little dial down a bit. Oh no, you’re in trouble.

Something I’m trying to get my engineers to be more cognizant of is the wireless mic gain. We used to put the mics in a tray and put them in the green room for the “on stage” folks to just pick up. But now we’re keeping them at the front of house console. That way, we can help them get the mic fitted properly, show them how to use it if it’s new to them and most importantly, adjust the gain on the pack before they’re 100 feet away on the stage (and while we can lay eyes on the receiver so we know what we’re doing!).

So here’s my procedure. Speakers and actors must pick up the mic at the sound board. Before they will strap on said mic, while standing there, they will give us a realistic level while we adjust the gain on the pack.

They will then proceed to the stage at the appointed time for sound check, and we’ll do the gain trimming and level adjusting for the house (and monitors if necessary).

At the end of the service, the mics will be delivered back to the sound board so that batteries can be recharged and so we don’t have to chase people all over the church looking for them.

Yep, that input gain control is the most important setting, whether it’s on the bodypack or the console. Getting this right just makes your day go so much easier. Get it wrong and you’ll hear, “Why was Jack all crackly and distorted for the whole message – it was really distracting!”

And that, my friends, is not good sound (apologies to Alton Brown).

Mike Sessler is the Technical Director at Coast Hills Community Church in Aliso Viejo, CA. He has been involved in live production for over 20 years and is the author of the blog, Church Tech Arts . He also hosts a weekly podcast called Church Tech Weekly on the TechArtsNetwork.

 

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Posted by Keith Clark on 05/23 at 08:53 AM
Church SoundFeatureStudy HallConsolesEngineerMixerSound ReinforcementTechnicianPermalink

Tuesday, May 21, 2013

One-Stop Shopping: Captain, What Does It Mean, This Term “Full Production”?

The sound company’s job is to advance the show with the artist and show up with a rig. Not so when the full production falls into your lap.

Sound companies handle “one-off” shows every day. It’s usually formulaic, and after a while, we do it by rote. 

But what happens when the client wants one-stop shopping? This is also known as “full production” or “turnkey service,” and it’s quite a bit more involved than an average show. Generally months of planning and coordination are needed, as well as work with a number of subcontractors. It just can’t be done by the seat of the pants.

Normally, when a sound company is hired for a show, the client is a promoter or a venue. They provide the stage, they provide the power, and they provide the labor. The sound company’s job is to advance the show with the artist and show up with a rig. Not so when the full production falls into your lap.

Particularly for large, multi-stage festivals, hiring a single source to handle all the entertainment elements of the event is almost a necessity. The event director has too many other things to handle to have to worry about the details of his entertainment. 

Steve Rosenauer, director of the St. Mary’s University Alumni Association Fiesta Oyster Bake in San Antonio, Texas, once told me his definition of full production: “As a client, full production means working with a knowledgeable and experienced company that can produce a turn-key operation with regard to organizing, building and operating the necessary staging, sound, lights and equipment needs, with all meeting the negotiated specifications of the event as well as the bands. A company that does this can greatly enhance the quality of the event and provide a solid peace of mind to the entertainers and the event organizers.”

For the purposes of describing the process of a full production event, I will use the Fiesta Oyster Bake as my example. It’s a two-day, six-stage festival which kicks off San Antonio’s annual Fiesta Celebration every April. Fiesta has been ranked as the second largest party in the U.S. (Mardi Gras being first) by the National Meeting Planners Association. (And yes, they bake tons of oysters!) For years, our company, Sound Services, worked with this event. (Note that we recently chose to close the company for reasons completely unrelated to business.)

PREP MAKES PERFECT
In order to be ready by mid-April, we would start working in November. To be fair, we had been doing this event for nearly a decade, and had amassed a team of subcontractors with whom we were all very comfortable. Until a company gets to this point, preparations probably need to commence even sooner.

In November, we would begin talking about what our needs were going to be. Because city electrical inspectors were involved, we checked the City Code Compliance for any new electrical requirements. For example, one year (and for the first time), we were required to ground all of stages to the audio power distribution services, as well provide non-conductive covering of all power cables running in public areas. Not fun to discover things like this at the last minute!

We provided staging, sound, lights, backline, labor and all technical personnel for the festival. Because the client uses many more generators than just ours, they made those arrangements, but they used our generator provider so we were assured that power would not be a problem. The generator provider also stayed in contact on any change orders he received that might affect us.

Also by November, the client usually had more than half of the talent booked, so we got a vague idea of what to expect from headliners’ riders. By December, we started talking with our subcontractors, discussing what had changed from the previous year, giving them the firm dates, and requesting a firm price by January. 

After ringing in the new year, and still four months out, it was time to nail down the financials. Be very meticulous with this process!  Everything must be committed to paper, and math triple-checked in order to avoid any mistakes that could cost an entire profit margin.

It’s doubly vital to get this facet correct in the first year with an event, because the client will base future projections on those first year costs. Therefore, a mistake probably can’t be made up for next year.

Only after every cost is defined and listed, as well as those of the subcontractors, should the price be committed to the contract submitted to the client. Note: the one thing we found most often overlooked is the cost of a production manager. The hours and hours you spend working on this shouldn’t be done for free!

WORKING IN EARNEST
We would submit our contract on the first of February, with the understanding that requests on artists’ riders would probably cause an increase in total price. By this point, the client had all talent booked, so we could start working in earnest to learn just what those extra costs might be. My goal was to have all this information by the 15th of the month, still two months out.

There is a negotiation with contract riders and advancing the show that can - with some diplomacy - help reduce the number of additional line items for your client. Because most headliners’ riders are based on arena shows, for example, they will often concede some lighting instruments. 

On the other hand, you don’t want artist representatives to think your client is cheap, so know where and when to stop asking for concessions. It’s important to manage your client’s expectations in this regard as well. Most touring artists also understand that festivals differ from concerts, so if the stages are adequately stocked to begin with, most of the added line items will be for backline and spotlights.

Once we determined all of the additional artist-related expenses, we submitted a contract addendum. This addendum should include absolutely everything - a. client will begin to lose confidence if presented with more than one price addition. His budget is set in stone by this time, and your math errors and oversights are not his fault.

MINIMUM OF 40
Because Sound Services was responsible for the entire Oyster Bake Festival, not just the two stages we were physically covering, it was imperative that we advance the show with every artist. In this case, we’re talking a minimum of 40 bands, which made for a lot of work. But it accomplished several very important things. 

First, we got a thorough look at the requirements of every stage, and were assured that each subcontractor could adequately cover the entertainment line-up. If there was a particularly tough set change on a stage at a particular time, we could arrange to have extra help on hand at that time. 

Second, it gave each artist a feeling of confidence to know that individuals who care about their performances run the festival. Third, we established consistency in the way the artists were handled. The subcontracting sound companies all appreciated this.

And fourth, we could apprise artists of the “special quirks” of this festival. For example, it’s held on a university campus that is, itself, located in a neighborhood, not on a major thoroughfare. Getting to the venue is difficult when 80,000 other people are also trying to do the same, and there is no alternate route.

Sometimes when we told first-time performers to allow three hours to arrive, some balked, but we remained adamant. The ones who didn’t believe us were invariably late, which is a no-win for everyone. (By the way, returning artists were never late!)

Further, artists can’t drive to any stages except the main one, because they’re all positioned among campus buildings. For this reason, full backline was provided at every stage, and musicians were discouraged from bringing more gear than they absolutely had to have. To accommodate this, the university set up a team of volunteers to ferry musicians and their gear to the stages. It took several years to streamline this process.

Once all the advance work was complete, we created stage plots and input lists for every stage, and for both days. These were then dispatched to the sound companies working the festival with us.

GETTING CLOSER
A pre-production meeting with the festival committee and all stage managers was held six weeks to two months out. Each committee reported on their progress and, although we weren’t involved in things like pizza ovens and beer sales, it helped us to know what was going to be happening around us. 

Entertainment production is an important part of this meeting, and we made it a real bonding experience. Construction of “Stage 1,” for example, meant an entire campus parking lot has to be closed two days prior to the event, and thus it was critical that the timing be executed properly by the university security department. 

We also got to meet the stage managers and orient them as to what was expected of them. These folks are critical for smooth-running shows, and we let them know that. While their duties are light, the few things we needed from them are all important to the show.

Other things covered in this all-important meeting were issues of water, green rooms, use of volunteers (there are hundreds!) and getting musicians to the event and their respective stages. Over the years, and learning from our mistakes, we developed methods to efficiently accomplish these tasks, but until you’ve worked with an event for a long time, these issues are extremely important to thoroughly think through. For example, from experience we all learned that as much water as we thought we needed - double it!

At this time, we also walked the campus with the festival director, making note of things like trees that needed trimming or light poles tp temporarily remove. (Grounds and electrical departments need to be notified in advance to schedule work like this!)

WHO’S DOING WHAT
By one month out, we had a firm grip on exactly who was doing what. For example, if there was a sound company short a monitor engineer, this was the time to step in and lend a hand. Each subcontractor provided us with a list of personnel and how many vehicles (and of what type) they would be bringing on site. One aspect to double-check: be sure each contractor is providing enough people. For example, backline duties done properly for six stages requires more than two techs.

At this point, we would tally up all production people (including stagehands and spotlight operators) and provide the festival director with the number of parking passes and wristbands needed. Remember - on a multi-day festival, each person might need a fresh wristband each day. We also padded this number by a few more to replace ones that were inevitably lost.

Very key: the best technical person on staff must be in charge of production management. Even with the best preparations, all kinds of little things can go wrong, especially at multiple stages. One person not involved in production at any one stage has to be free to fight the fires, and this person should be well versed in technical knowledge as well as diplomacy. 

Our production manager for the festival spent each day traveling between stages, providing a break to a beleaguered engineer here, dealing with a power problem there, handling a recalcitrant band engineer somewhere else.  He also carried a radio for instantaneous contact. And, this person must have healthy legs – in a very crowded festival, a golf cart won’t work!

Three weeks out, we assembled packets for all of the subcontractors involved.  These included parking passes and wristbands, a map of the campus showing all stages and parking areas, a complete schedule of the event, and for the sound providers, stage plots and input lists. Load-in times were also provided.

Scheduling personnel is critical at this point. We staggered the load-in times so that we could make the best use of our stagehands. Stagehands have a four-hour minimum, and each is usually scheduled to work at more than one stage during a shift.  For load-out, we scheduled a much larger number of stagehands. This schedule was then filed with the labor company as a written work order, and note that this also included spotlight operators as well.

IT’S SHOWTIME!
Two days before the festival, we began to build the stages. The provider arrived with semi-trucks loaded with staging, and we again walked the site with the festival director, spotting the stages, front-of-house risers, spot towers and security towers.

The day prior to opening, we loaded in at our two stages, which then left us free to address the mayhem of everyone else loading in the next morning. The lighting contractor also loaded in with us in order to be out of the way, and this left the lighting directors free to work with headliners who might arrive early. On-site security was continuous at this point.

Day one of the festival would arrive, and we were free to conduct headliner soundchecks on our stages. Fortunately, the first act didn’t begin until 6 pm, so the atmosphere wasn’t too stressful.

The production manager was also available to address the various surprises that unfold, as they invariably will. This is where months of planning pay off and you can look really good to the client, who’s running around putting out all kinds of fires while his production people are calmly doing their jobs.

If all subcontractors are competent and well prepared, the event should run like an average one-off show. One caveat, however: it’s still a multi-day, multi-stage festival, with thousands of people swarming all over, so competent, well-informed stage managers become critical to your existence. 

They aren’t needed to get artists on and off the stage – we had already planned that out. They are most definitely needed to competently answer artist questions - “Where are our food coupons?” and “Where is our dressing room?” and the like. They also kept lots of water on ice, and plenty of ice in the ice chests.

The most important thing stage managers did, however, was manage the radios. Each stage had a radio, as did the production manager and the lead backline technician, and they were on a common channel with the event director. 

As the production staff performed its various tasks, we didn’t have time to monitor a radio, but when we had a problem or needed help, we simply asked a stage manager to contact whomever we needed. Previously we carried individual radios, but learned that this alternative approach worked so much better for everyone, plus it gave the stage managers a sense of ownership of their jobs as well. 

The best advice: “be round.” Roll with the punches and don’t get too excited by the inevitable little surprises that spring up. Make the production of entertainment as smooth as possible and don’t create tension or problems. That’s a big reason you were hired!

THE AFTERMATH
When it’s all over, the results of diligent planning and scheduling should continue to pay off. We found that handling a large number of stagehands at the end of the festival worked best if we arranged for the crew chief to assemble all of them at a pre-arranged site and make assignments from there.

Stagehands were first dispatched to the stages manned by our subcontractors, then re-routed to our stages last.  We always got this show loaded out within our four-hour labor minimum, by the way.

The production manager continued to make a circuit of the stages, being sure each stage had its allotted stagehands and collecting any left-behind belongings. We later attempted to repatriate these items with their owners.

When all the dust cleared a week or two later, we sat down and created a recap of the event, and this went into the file for next year. We also sent this recap to the festival director. Included were a summary of any issues that came up, general incidents, what worked well and what didn’t, and suggestions for improving next year’s event.

By working with the client in this fashion, we made ourselves a part of the event team, and enjoyed a multi-year contract. We also ingratiated ourselves to our subcontracting partners, who appreciated the work and reciprocated when appropriate. 

It’s just good business to develop this kind of working relationship with your clients and fellow business people, and it leaves you feeling pretty good about yourself as well.

Teri Hogan is a long-time audio professional and was co-owner of Sound Services Inc., a sound company based in Texas.

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Posted by Keith Clark on 05/21 at 01:30 PM
Live SoundProductionFeatureStudy HallProductionAudioBusinessConcertEngineerSound ReinforcementTechnicianPermalink

You Make Music You Say? So, You’re In The Fashion Industry

Inside the evolution and development of sounds through the decades that have become marketable commodities

The sound of popular music can be clearly compared to other forms of seasonal commodities such as clothing fashion and hairstyles.

Much as bell-bottoms, the hula-hoop, and whitewall tires have become fashion statements associated with certain times past, “the sound” of most records will in later times provide a key identifier in time stamping that music.

Like fashion, some of these sounds periodically re-emerge; some become an ongoing fabric of music production, while others are never heard of again.

We live in a time of interchangeable parts; music is in an advanced state of industrialization, where mass produced components are used and reused in everything.

The 1990s was the re-decade of reissue, review, reflection, reuse, repurpose, and reprocess. Déjà vu was the prevailing vu for most of the population. The vast reissue on CD of long-lost catalogs has allowed all previous decades to be available in our time.

Today’s record producers have the texture, style and tone of all previous decades to draw upon. Many records today have some production aspect or sound taken from the past - the sound of nostalgia. Songs and fragments of songs from the past in the latest music stimulate the recollection of countless personal histories.

As in any other commodity/consumer paradigms, consumerism and commercialism drive this thirst for new sounds. The predominately young music consumer seems to have a never-ending appetite for what is new from the music industry because it defines them as different from their older sister, their younger brother, their parents, all other generations. 

Unlike the fashion industry, where styles are seldom worn past their season until a generation later when they may be rediscovered, greatest hits collections and classic albums from every period remain part of the active playlist of life.

In fact, the greatest hits of any year will be on the market by mid-year and blasting from every radio during end-of-summer long weekends. These recordings form sonic postcard collections of memories good and bad.

Before records were invented and technology’s impact on music production, musical passages and phrases, a good story, a singer’s performance, and a memorable chorus were the primary identifiers of a pop song. They remain important, but these “hooks” now include “the sound”.

Those in music production often refer to the sound of a recording separate from the song. A recording can have a good or unique sound that catches the public ear and at the same time the song may be inconsequential. 

As Dick Clark once commented “(the sound is) what the kids listen for… the more different, the more original, the more unique the sound is, the more chance a record has of becoming a hit”.

“The sound,” in many cases, could be described as a formula that in and of itself is a marketable commodity that is, in the first instance, sold by a producer to the record label.

The ingredients, which make up this formula, come together as new devices become available and naturally enough each subsequent wave of music producer builds on and modifies earlier formula. Often they are so identifiable with the state of the technological art of the time that the trained ear can place the year of production based on the sound.

Geography plays a part in identifying styles. At various times a swarm of hits will emerge from a certain geographical region where there is a vibrant scene and a community of musicians.  Their collective style becomes identified with that place.

The sound of New Orleans, Chicago, Motown, San Francisco, TexMex, Merseyside, Londonbeat, Memphis, Liverpool, West Coast, Mid Atlantic, Berlin, Nashville, Jamaican, Brazilian, Casa del Sol, and Euro are just a few of the places associated with a certain style of sound that have received world wide attention during a certain period of time.

In 1925, Victor and Western Electric engineers oversaw the first electrical recording sessions that would produce usable masters for Victor. (click to enlarge)

Sound and music became a commodity incrementally starting at the beginning of the 20th century when records first captured and fixed a performance. It took a second leap when electric recording first appeared in the late 1920s, and another when tape recording was developed in the 1940s. 

But the greatest leap occurred when Les Paul changed the recording studio from a place where a performance was documented to a place of creation. He was the first to use the technique of “sound on sound” or overdubbing, a cornerstone of the modern pop music sound, and was years ahead of what has become common practice.

Using this technique, Les Paul teamed up with vocalist Mary Ford and they changed the way pop music sounded. Together they had 28 hits from 1950 to 1957. The best known are “How High The Moon”, “Mockin’ Bird Hill”, “Vaya con Dios”, and “Tiger Rag”. 

By and large, The music industry of the day saw multi-track and the “overdubbing” technique as Les Paul’s sound, and not a general tool for music production. In the early 1960s, the Beatles and The Beach Boys would change all that.

Les Paul working his multitrack magic in the 1950s. (click to enlarge)

The “Les Paul” sound was a production technique that become a bankable commodity. Such techniques are often associated with sounds that people have never heard before.

In the 1950s, Ross Bagdasarian had been making records as a songwriter and arranger. He had a particular knack for writing novelty songs, and in 1958, had a hit with “Witch Doctor” in which he sonically conveyed a shrunken head singing by recording the vocals at half the tape speed used to record the instruments and then playing it all back at normal speed. The singing went up in pitch by an octave.

Later that year, he invented an alter ego, David Seville, and introduced a vocal trio using the technique as on his earlier hit. “The Chipmunk Christmas” sold 3.5 million copies in five weeks, and from 1959-80, Alvin, Simon and Theodore made eight chart albums selling over 30 million copies.

In more recent times, they could be seen on Saturday morning cartoons, and a few years ago, Bagdasarian’s son brought the Chipmunks back, where they’ve starred in a number of successful animated features. These days pitch-shifting their voices is a plug-in.

Phil Spector created another landmark pop sound, noteworthy because he may be considered the first record producer to have attained “star” status. Spector’s “Wall of Sound” hits with The Crystals, The Righteous Brothers, The Ronettes, and Tina Turner’s classic “River Deep-Mountain High” were exclusively associated with the reverb chambers at Gold Star Studios in Hollywood.

Many other top artists of the era also used these same chambers, including Sonny & Cher, Iron Butterfly, The Rolling Stones, The Beach Boys, and Herb Alpert and the Tijuana Brass. In fact, the Gold Star chambers were so popular that the owners built two copies and leased them to other studios, linked by high-quality telephone lines. The Phil Spector sound and those chambers were a commodity for a while in the 1960s.

Unique sound may come from a state-of-the-art device, or a vintage piece of equipment, because unlike other types of media that drop older state of the art in favor of the latest innovations, sound producers prize vintage microphones, sound generators and processor devices for the qualities they have.

Some of these qualities are so characteristic that modern digital multi-processors have presets that attempt to create the attributes of these vintage devices. The manufacturers of production equipment have, in a sense, made a commodity of sound processes.

Phil Spector (foreground) building “walls” in the 1960s. (click to enlarge)

And, of course. there is the emergence of manufacturers of audio equipment that pride themselves in offering exact duplicates of what are now legendary devices from an earlier time.

For the music producer/engineer, the latest techniques and “sounds” are directly associated with the hardware. Hundreds of production equipment manufacturers jostle for market share. NAB and AES trade show booths beckon aisle-strolling musicians, producers, and engineers to have a listen to the latest new thing. 

The most popular processes become commodities in the marketing and application of these devices. By the next show, today’s hot new sound will inevitably be copied and included in any number of devices by other manufacturers.

The sounds that these devices create may be as clearly identified as a specific preset program on a digital effect, or it might be quite beyond a layman’s description.

In either case, the sound created will be tangible to those who care, if by no other way then through some comparison to earlier sounds, processes, and recordings.

The variety of effects would seem to allow an infinite number of sounds to be used on the myriad of recordings made; however, in practice, this has not been the case. The desire of producers to make records that sound commercially familiar has created a remarkable number of productions that sound alike.

The phenomenon has been made easier by the variety of pre-set programs that come with most sound generators and processors. By switching from one setting to another, the sounds from dozens of records can be heard. The preset computer program in the processor generates nothing except in response to a signal passing through it. Here we have sonic artifacts that have become marketable commodities.

For instance, reverb sounds are cataloged by the type of instrument that might go through it as suggested by the manufacturer. A gated reverb snare exists on every processor made today.

Most reverb devices retain preset descriptions that reference devices of the past. A good example are “plate reverbs”, a reference to a mechanical device invented by EMT that in the mid-1960s revolutionized how reverb was generated in a studio.

The heart of rock and roll may be Cleveland, but it sounds like guitar distortion; in this case a common denominator is the Celestion G12 loudspeaker that is in an overwhelming number of guitar amplifiers made by a number of different manufacturers.

Ken Bran, the engineer who headed the introduction of the Marshall amplifier that was first made famous by Hendrix and Led Zeppelin, acknowledged that without Celestion, they couldn’t have accomplished that sound.

The Marshall amp that first incorporated the classic Celestion G12 loudspeaker driver. (click to enlarge)

In the beginning, Celestion was probably unaware of the desirability of loudspeaker distortion. The company had spent decades trying to build distortion-less loudspeakers, but came to understand that distortion was actually a key selling point.

As Celestion’s promotional material states, “The paper edge cone of the classic G12 and it’s resonate break-up characteristics are the starting point from which many of the modern guitar loudspeakers have been developed”.

This loudspeaker was first introduced in 1969 and continues to be sold with the assurance that the characteristics of its distortion hasn’t changed through the years. Here is the subjective, absolutely unquantifiable attribute of some form of unique distortion that has become a marketable commodity.

During the past few decades, an abundance of performance processors have been invented to add distortion to the sound coming out of a guitar. Two are particularly noteworthy.

The fuzz-tone effect pedal was first marketed in 1963, and as Charley Watkins described, “It was an exciting sound - as if the speaker cone was being torn apart.” In 1963, “Hold Me” by P.J. Probe was one of the first chart records to use a fuzz-tone, but the record to place fuzz-tone effects at the top of any guitar player’s shopping list was the 1964 debut single for The Rolling Stones, the classic “Satisfaction”.

Interestingly, Keith Richards dismissed the prominence of the fuzz effect as a gimmick. Countless recordings have been done with variations of that fuzz-tone sound.

The second is the cry baby wah wah pedal, which can make the guitar sound as though it were speaking. As the pedal is rocked back and forth. a notch of frequencies are enhanced.

The wah wah remains a backbone sound of rock blues soul music and became a recognizable commodity when used by Jimi Hendrix on “All Along The Watch Tower” and Eric Clapton on Cream’s 1967 hit “Tales of Brave Ulysses”.

Stereo itself became a fashion statement soon after it was introduced in the late 1950s when the first generation of “ultimate” playback systems appeared on the market.

People would fill hi-fi stereo shows that were held in most major cities. A great many successful recordings were produced for the stereo enthusiast. Trains, bongos and guitar solos would race from one speaker to the other.

No matter how small the listener’s accommodation might have been, the infinite space of recorded music could overlap and open the confined space the listener occupied. The sonic image of space had become a commodity. 

Since those days when the pan knob was added to consoles, signal processing has become significantly more elaborate, diverse, and much more than merely an enhancement tool for the sound entering the microphone. It has become an integral part of the overall production.

Today, where the “musical instrument sound” ends and the “effect processor sound” begins is in most cases seamless. The development of 5.1 surround sound has allowed the consumer hi-fi industry to reinvent itself, as the consumer now sits in the showroom and hears why six loudspeakers are better then two - all the better to hear space ships wiz around the room.

Currently residing in Australia, Tom Lubin is an internationally recognized music producer and engineer, and is a Lifetime Member of the National Academy of Recording Arts and Sciences (Grammy voting member). He also co-founded the San Francisco chapter of NARAS. An accomplished author, his latest book is “Getting Great Sounds: The Microphone Book,” available here.

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Posted by Keith Clark on 05/21 at 06:15 AM
RecordingFeatureBlogBusinessDigital Audio WorkstationsEngineerProcessorSoftwareStudioPermalink

Friday, May 17, 2013

From Simple to Complex: The Wide World Of Drum Microphone Techniques

Drum sound can enhance or degrade an entire mix, so be sure to pay it due diligence

A drum kit can be viewed as a single instrument. Like an orchestra, it can be captured with a pair microphones in a stereo configuration (or a single stereo mic). Or, it can be viewed as a collection of individual instruments, picked up with numerous close mics.

A minimal approach (Figure 1, below), also sometimes called area miking, uses only one or two mics overhead (or maybe a stereo mic), another in the kick, and maybe one on the snare.

The mics pick up the set as a whole, and the balance among the drum kit pieces depends more upon the drummer. Area miking tends to work best with acoustic jazz and other types of acoustic music.

Typically, overhead mics are placed about 2 feet above the “front” of the cymbals, while the snare mic is a couple of inches over the rim aiming at the center of the head, and the kick mic is inside, near the beater.

For traditional jazz, where the kick drum is often tuned to be intentionally resonant – even a bit boomy – the mic is more commonly placed by the front head of the drum.

Something to try: reverse the polarity of the kick mic to see which polarity sounds best for your application.

Condenser models are a good choice for overheads because they provide a sharp transient response that accurately reproduces the cymbals. Large-diaphragm condensers tend to capture the fullness of the toms better than small-diaphragm units.

Also don’t be afraid to try dynamic mics. Many classic rack-tom and floor-tom sounds have been captured with Sennheiser MD 421s, Shure SM7s or SM57s, and quite a few others. 

Figure 1: A minimal mic approach. (click to enlarge)

The Ol’ XY
An overhead stereo pair can be coincident, near-coincident or spaced. The coincident-pair (XY) stereo technique yields a narrow stereo spread with sharp image focus, while the spaced-pair method provides a wide spread with more diffuse images. If the cymbals are too loud relative to the toms and snare, raise the overhead mics, lower the cymbals.

Since the mics are relatively far from the kit, they also pick up room acoustics and sometimes other instruments. Room reflections can make the sound a little distant and muddy. This can be good or bad; depending on the type of music, the sound you’re going for, and so on.

Careful placement (particularly moving the kit away from walls) can minimize or eliminate the problem. In churches (and some clubs), it’s common to see a plexiglass barrier placed around the drum kit, intended to keep the acoustic sound of the drums from overpowering the vocals and other instruments. 

When lowering the overhead mics, exercise caution or the cymbals can easily become too loud.

Another approach is to place the mics near each side of the drummer’s head, so that they “hear” the kit in stereo pretty much as the drummer hears it.

Apply EQ as needed to compensate for Fletcher-Munson loudness contours (how the ear hears different frequencies at different levels).

A nifty “minimalist” technique that can work with a small kit is clipping a mini omnidirectional condenser mic to the right side of the snare drum rim, a few inches over the rim, over the drummer’s knee (Figure 2). It will pick up the snare, toms and cymbals all around it.

The resulting sound is tight and full, somewhat like that of multiple mics.

To adjust the balance among the drum-kit parts, position the mic toward or away from the toms, and raise or lower the cymbals.

Figure 2: A single mini omnidirectional mic plus one for the kick. (click to enlarge)

The single-omni method limits what can be done with EQ. Boosting the higher frequencies (2 kHz and up) to bring out the toms’ attack can add an unwanted harsh or metallic effect to the cymbals. It’s better to use subtractive EQ in the low frequencies, roughly 100 Hz for the toms and 200 Hz for the snare.

Mic Multiplicity
With a multiple-mic approach (Figure 3), one mic is placed close to each drum and cymbal. That provides extra control of the EQ and effects for each drum independent of the others, resulting in a tighter, more present sound.

Toms, in particular, benefit from individual miking, for a richer and more distinctive sound. Multiple miking is the norm for rock and fusion.

A common snare mic is a cardioid dynamic type with a presence peak in the frequency response, such as the Shure SM57 or Beta 57A. Bring the mic in from the front of the set on a boom and place it a couple inches over the rim aiming at the center of the head.

Figure 3: Multiple miking. (click to enlarge)

The sound will be full with the mic near the top head, and thins out and becomes brighter as you move the mic toward the rim and down the side of the drum.

Some engineers like to mike the snare drum top and bottom. If this approach is taken, reverse the polarity of the bottom mic to prevent phase cancellations. The bottom (snare) head moves out when the top (batter) head moves in, so the heads are in opposite polarity and can cancel out each other’s sound if you mix their signals.

Some snare drums make an ugly ringing sound at a particular frequency. To eliminate it with EQ, insert a high-Q, narrow peak in the 200 Hz to 600 Hz range. Sweep the frequency up and down until you exaggerate the ring frequency, then apply cut.

Here are some suggestions to prevent hi-hat leakage into the snare mic: mike the snare closely; bring the snare-mic boom in under the hi-hat and aim the snare mic away; use a piece of foam or pillow to block sound from the hi-hat; and consider using a de-esser on the snare.

For toms, a good choice is a cardioid dynamic mic with a presence peak and a deep low end such as the Sennheiser MD 421.

Place the mic about 2 inches over the rim and 1 inch inward, angled down to aim at the center of the head.

The usual EQ is a cut around 400 Hz to 600 Hz to remove the unwanted artifacts, as well as a boost around 5 kHz for attack. Another boost around 80 Hz to 100 Hz adds fullness.

It’s common to gate the toms to reduce the low rumble of vibrating heads and to prevent leakage, resulting in a tighter sound.

To do this, solo a tom track, insert a gate in the track, and then while the tom is playing, gradually turn up the gate’s threshold until the gate cuts off the sound between tom hits but does not cut off the hits themselves.

Finally, set the gate’s hold time to 0 to 100 milliseconds, whatever sounds good.

Highs & Lows
Place overhead mics about 2 feet over the cymbals, and if possible, use condenser or ribbon types with a frequency response that is flat to 15 kHz or even 20 kHz. This characteristic captures the delicate, beautiful “ping” of the cymbal hits, while a peak in the highs tends to sound harsh.

Usually the snare mic, overheads, or room mic pick up enough hi-hat. But if you want to mike it separately, aim a condenser mic down about 8 inches over the edge farthest from the drummer. Apply a high-pass filter at 500 Hz or higher to reduce snare leakage and to remove the low “gong” sound that close miking would otherwise pick up.

You might apply a high-pass (low-cut) filter to the overhead mics that capture the cymbals to remove frequencies below 500 Hz to 1 kHz. This will reduce drum leakage and room reverb in the cymbal mics, which is especially helpful if the room acoustics are poor.

Kick drum is largely a matter of experimentation. Some place a blanket or folded towel inside the drum, pressing against the beater head to dampen the vibration and tighten the beat. The blanket shortens the decay portion of the kick-drum envelope. To emphasize the attack, use a wood or plastic beater – not felt – and tune the drum low.

Figure 4: Positioning the kick mic. (click to enlarge)

For starters, place the kick mic inside on a boom, a few inches from where the beater hits (Figure 4), if the front head has been removed. Mic placement close to the beater picks up a hard beater sound; off-center placement picks up more skin tone, and farther away picks up a boomier shell sound.

Current practice among many drummers is to use a front head with a small open sound hole, in which case the mic should be placed directly in front of the opening. Kick drums are usually tuned quite low for a sharp attack sound used in pop or rock, and much higher for traditional jazz.

To create a “tight” rock-type kick sound – almost like a dribbling basketball – cut several dB around 400 Hz and boost around 2 kHz to 4 kHz.

Mics designed for the kick drum usually have that characteristic built in.

If the kick drum does not have a hole in the front head, just mike the front head and boost around 2 kHz to 4 kHz to add attack if needed.

A popular microphone design for kick drum is a large-diameter, cardioid dynamic type with an extended low-frequency response.

Some mics are designed specifically for the kick drum, such as the AKG D112, Audio-Technica AT AE2500, Shure Beta 52A, and the Electro-Voice RE320, which has a curve that’s switchable to being optimized for kick drum applications.

Finally, when miking drums on stage, you don’t want a forest of unsightly mic stands and booms. I suggest “banquet style” mic stands and short mic holders that clip onto drum rims and cymbal stands (such as those from Mic-Eze at www.ac-cetera.com). Another option is to use mini drum mics with built-in clamps and goosenecks.

Drum miking can be simple or complex. As with all things audio, it depends.

One thing that really helps is being as familiar with the sound of as many aspects of the drum kit as possible. This means a lot of listening to a wide range of styles and different types of players.

Those who play very hard with heavy sticks present challenges that are quite different from those who play more quietly, or with a greater dynamic range.

The bottom line is that the drum sound can enhance or degrade an entire mix, so be sure to pay it due diligence.

Bruce Bartlett is a microphone engineer (www.bartlettmics.com), recording engineer, live sound engineer, and audio journalist. His latest book is “Practical Recording Techniques 6th Edition.”

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Posted by Keith Clark on 05/17 at 04:08 PM
Live SoundFeatureBlogStudy HallMicrophoneSound ReinforcementStagePermalink

Thursday, May 16, 2013

Avoiding Poor Judgment & Getting A Handle On Subjective Audio

Using instinctive knowledge to judge the loudness of a system

I suspected trouble when I accepted responsibility for something I had no control over. There was a 50/50 chance of either being the hero or the whipping boy. I didn’t care for those odds, but I couldn’t change them.

It all started when a friend of the family asked me to help make sure that the sound for his wedding didn’t ruin the ceremony. The catch was that I wasn’t handling the sound - his cousin, the part-time DJ, had that job.

I’m not sure if he asked me because he respects my experience, or because he was afraid Cousin DJ would do something to cause the bride to cry. I prefer to think it was the former, and so chose not to ask for clarification.

Enter the rehearsal. Cousin DJ showed up at the outdoor location with a small powered mixer and a single loudspeaker, but forgot the adapter to patch in his laptop. Fortunately, someone had an iPod and dock with speakers; at least we managed to get playback, tinny as it was.

So the rehearsal was a waste, but we’d be able to make it up before the ceremony since Cousin DJ likes to show up two hours early to get everything setup and checked (paraphrased). Plenty of time to set up and prove the system, as well as soundcheck the guitarist/singer.

Come wedding day, Cousin DJ arrives 40 minutes before the ceremony is scheduled to start. Only 80 minutes late, but hey, at least he brought his trusty sidekick. I already had power waiting, a condenser microphone ready for the acoustic guitar, and when they pulled up, I helped muscle the gear into place. 

But once this was done, things changed. Immediately it became obvious that Cousin DJ and trusty sidekick had a “method” all their own -  and I was an outsider. I didn’t fight it. After all, the day wasn’t about me.

The loudspeakers were placed directly on the ground, the classic smile slapped on the graphic EQ, and the mic I brought for the acoustic guitar was pushed aside for an SM58. I put my mic back in the family minivan next to the two cases of stuff I’d brought along to cover for Cousin DJ in case he forgot something critical.

So how’d the sound for the ceremony turn out? 

The overall volume level should have been louder, but it couldn’t be turned up because the system would have gone into feedback. Actually, though, this was a blessing in disguise, because had it been louder, we would have been inflicting earlash (distortion, etc.) due to the EQ setting.

There was also a hash of noise from the laptop that’s typical of the onboard audio jacks of most sound cards. And last but not least, the woofer on the right speaker kept cutting in and out during the processional.

In the end, my involvement came down to a nervous groom wanting to be sure that everything was going to come out all right. Since ignorance is bliss, the sound was just fine as far as the wedding party was concerned. They had other things on their mind.

Beyond the technical problems that were encountered, the ceremony was marked by what I would classify as poor production judgment.

I highly recommend reading Bob Thurmond’s articles on PSW (here and here) about defining a good system.  He’s obviously a seasoned professional with much knowledge and experience, and I came away from his articles with renewed understanding.

Bob touches on the complexity of the problem of trying to uniformly quantify the attributes of a good sound system. Logically, this also extends to every aspect of our craft, where we’re trying to get a handle on what’s ultimately a subjective experience.

After the wedding, I had lunch with Chris Gauvin, a local corporate sound pro. Our conversation meandered here and there, and since he had a forthcoming concert gig, he asked me about my thoughts on band and music mixing. I answered as I always do: 80 percent of the job is getting the levels right - not only the individual elements, but the whole mix.

Yes, EQ, effects and compression can help make things better, but when it comes down to the meat and potatoes, getting the levels right is the majority of the craft. Achieving this takes a process of good production judgment.

But that judgment can only be properly made when you have the solid foundation of a personal quantification system. As humans, we’re wired for communication. The one absolute that we all have is knowing exactly how loud we have to speak for someone else to hear us clearly. 

Learning how to use that instinctive knowledge for judging the loudness of a system, and understanding where various types of events belong in that reference, can be a powerful tool.

Now, I’m not going to talk badly about those in our business who set an objective loudness standard and use SPL meters to stick to it. Mainly because I have absolutely no objection to this line of thinking. 

But speaking from experience, if you’re doing this, make sure it’s loudness you’re trying to keep a handle on - and not earlash. The worst thing you can do to treat earlash is to deprive the audience of the appropriate listening experience. 

Solve the earlash issue and you’ll probably find that the need for an objective loudness standard isn’t so rigorously necessary. Good? Again, yes, but not so absolute.

Since his start 29 years ago on a Shure Vocalmaster system, James Cadwallader remains in love with live sound. Based in the western U.S., he’s held a wide range of professional audio positions, performing mixing, recording, and technician duties.

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Posted by Keith Clark on 05/16 at 05:08 PM
Live SoundFeatureBlogEngineerMeasurementSignalSound ReinforcementSystemTechnicianPermalink
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