Wednesday, June 20, 2012
Community Soups Up Richmond International Raceway
“America’s Premier Short Track,” as Richmond International Raceway is known, is home to the annual NASCAR Sprint Cup Series and NASCAR Nationwide Series, as well as a full calendar of other events.
With most races held under the lights, the 94,000-seat venue is outfitted with the latest in high-tech lighting, signage and sound, including a unique system of rear-firing loudspeakers from Community.
The track is covered by an assortment of Community WET and R-Series loudspeakers, mounted on poles behind the grandstands at a height of 25 to 30 meters.
The system, designed by Wrightson, Johnson, Haddon & Williams (WJHW) and installed by Parsons Electric, is powered by Lab Gruppen amplification and utilizes Lake Systems DSP to provide delay and processing via a Dante network controller and fiber-optic digital distribution network that streamlines control of audio and video throughout the entire venue.
As WJHW’s Jack McCallum explains, the rear-mounted system provides improved coverage and better sightlines for the audience and television cameras.
Selected for their superior weather resistance, powerful output, exceptional coverage and high intelligibility, Community WET and R-Series loudspeakers are a popular choice for many of the nation’s racetracks, sporting arenas and other venues where power and performance are key.
Britannia Row Productions Relies On Outline For Diamond Jubilee Events
A wide range of events marking the sixtieth anniversary of Her Majesty Queen Elizabeth The Second’s accession to the throne in 1952 took place across the long weekend of June 2nd-5th.
Being only the second time in history that a sovereign has reigned for six decades, the occasion prompted celebrations on a truly global scale - literally millions of people throughout the UK and the Commonwealth marked this extraordinary occasion with celebratory events of every imaginable kind.
London was the epicentre of the international party, with a 1000-vessel river pageant (an event not seen on the Thames for 350 years), many special exhibitions throughout the capital’s museums and galleries, a service of thanksgiving at St Paul’s Cathedral and a star-studded music concert.
The concert, organized by Gary Barlow, took place on Monday June 4th and featured rock royalty including Sir Paul McCartney, Sir Cliff Richard, Sir Tom Jones, Sir Andrew Lloyd Webber and Sir Elton John, Stevie Wonder, Dame Shirley Bassey, and many, many more. A unique temporary stage was constructed for the event on and around the Queen Victoria Memorial in front of Buckingham Palace.
Britannia Row Productions was engaged to handle the audio production, and deployed systems to cover not just the concert but also the full length of The Mall, St James’s Park, Trafalgar Square and Hyde Park (where an Outline GTO system was used on the Commonwealth Stage).
For the main concert area Britannia Row designed and deployed a main system comprising 96 Outline Butterfly enclosures with 48 Outline Subtech subwoofers for the audience of 20,000 invited guests standing in front of and seated in tribunes around the temporary stage.
Britannia Row’s MD Bryan Grant said, “Our brief was to provide an ‘invisible’ PA - no towers, no flown arrays, but of course it had to sound perfect! We therefore decided on a small, powerful, distributed system and our Outline Butterfly was the obvious choice.
“We provided six inner Butterfly arrays each stacked four high in the moat to stage height, with a further eight units arranged as infills on and under the forestage. The main delays consisted of eight stacks, each six high on platforms in front of the bleachers, with another sixteen Butterfly located as secondary delays in the entrance of The Mall.
“A ring of Subtechs around the outside of the moat and beneath each delay stack provided the low end, which I have to say was very impressive.
“We’ve had many compliments on the quality of the live sound so I’m pleased to say the plan worked!”.
Tuesday, June 19, 2012
Shure Adds Dual, Quad Receivers To ULX-D Series (Includes Video Coverage From InfoComm 2012)
Shure is extending its ULX-D Digital Wireless Microphone System with new multi-channel receivers, a High Density mode that enables 47 systems to operate in just six MHz of spectrum, and integrated Dante digital audio networking.
The new ULXD4D dual channel digital receiver and ULXD4Q quad channel digital receiver pack two or four channels of wireless into one rack space, with individual gain controls, LED meters, and XLR outputs for each channel.
Like the single-channel, half-rack ULXD4 digital receiver, the new dual and quad receivers feature fully digital audio processing and RF transmission as well as AES 256-bit encryption.
“ULX-D has already set a new bar for audio quality, spectral efficiency, and features with its intelligent rechargeable batteries and AES256 encryption,” said Erik Vaveris, Category Director for Wireless products at Shure. “The addition of full-rack dual and space-saving quad-channel receivers provides customers with professional form factors and an amazing list of new features and enhancements.”
The dual and quad receivers add two new features that make using a large number of systems not only possible, but simple.
Selecting High Density mode enables up to 47 ULX-D systems to operate in just six MHz of spectrum (equal to one U.S. television channel), with a working range up to 30 meters. High Density mode optimizes the system’s output power and digital RF filtering to reduce its spectral footprint from 350 kHz to 125 kHz, with no loss of sound quality.
This lets ULX-D systems be tuned to frequencies that are much closer together without interfering with each other. Even in Standard mode, up to 17 ULX-D systems can operate in six MHz.
“High Density mode provides a unique option for getting an unprecedented number of microphones on the air,” added Vaveris. “As spectrum challenges continue to increase, High Density mode is a key tool for systems integrators who need to maximize the amount of microphones that can reliably operate in less spectrum.”
The ULXD4D and ULXD4Q receivers are also equipped with integrated Dante digital audio networking, which enables multiple channels of audio to be distributed to a variety of devices over a single Ethernet cable, including Yamaha’s new CL Series consoles.
Dante networking provides reliable, low latency audio transport, and can coexist safely on the same network as IT and control data. Shure has executed a licensing agreement with Sydney, Australia-based Audinate for the Dante digital audio networking technology.
Launching the dual and quad receivers at InfoComm makes perfect sense because their feature set is so well suited to the needs of systems integrators.
Starting with ULX-D’s remarkable audio and RF performance, adding Dante Digital audio networking provides a great way to simplify set up while also increasing flexibility in installed sound systems. Include features like bodypack frequency diversity, a reliable and intelligent rechargeable battery system, and digital encryption, and you have a wireless microphone system that can meet the needs of just about any sound reinforcement application.
Live coverage of the new ULX-D systems from InfoComm 2012:
CTW InfoComm 2012 Coverage: Shure ULX-D Dual and Quad Receivers from Mike Sessler on Vimeo.
The new ULXD4D and ULXD4Q receivers will be available in late summer 2012 through authorized Shure resellers in numerous configurations with a wide range of Shure microphone options.
L-Acoustics Key Appointments Focus On Installation Market
L-Acoustics has further strengthened its commitment to the North American fixed installation market by announcing the appointments of Dan Palmer as National Manager of Installation Projects and Andrew Nagel as Head of Application for the US Installation Market.
Palmer, currently in his eighth year as a member of the L-Acoustics US Team, is experienced in both the technical and business aspects of professional audio, having spearheaded numerous installation projects for L-Acoustics, ranging from sports venues and themed entertainment to houses of worship and performing arts.
In his new role, Palmer will focus on developing strategic relationships for L-Acoustics and various market development activities across multiple segments of the US installation market.
After completing several high profile installation projects for L-Acoustics worldwide, Andrew Nagel embraces an expanded nationwide role as Head of Application for the US Installation Market. In his new leadership capactiy, he will be responsible for all aspects of sound design assistance and solutions, providing on-site support for challenging projects, creating potential system models, and conducting technical trainings and product demos for L-Acoustics Certified Providers.
Cedric Montrezor, Director of Application, Install states: “Given his proven track record as a talented A/V designer, I am convinced that Andrew will successfully support our Certified Provider install network and the consultant community in their projects.
“As for Dan, his exceptional commitment to L-Acoustics and dedication to customer satisfaction will be instrumental in the development of our activity in the various segments of the US fixed installation market.”
“L-Acoustics has recently won many accolades in the installation sound market for its dedicated high performance product line, but also for its outstanding customer support and design expertise,” adds Laurent Vaissie, General Manager for L-Acoustics US. “Dan’s unique blend of business-savvy and technical knowledge makes him the natural choice to expand our market awareness and development efforts, while Andrew’s formal technical background and unique expertise in complex sound design will provide exceptional support to our growing network of system integrators and consultants.”
Behringer Unveils Eurocom Products At InfoComm
Behringer is pleased to present its EUROCOM line at Infocomm 2012. The EUROCOM line is a series of state-of-the-art tools for modern systems integrators.
“We’re thrilled to showcase our new products at Infocomm,” says Costa Lakoumentas, SVP Marketing of Behringer. “Our lineup combines innovative, professional technologies with aesthetic designs for exceptional performance quality—all at an affordable price. We are confident EUROCOM will set new standards in the integrator market.”
The AX Series dual-channel amplifiers epitomizes power and control offering contractors flexibility and efficiency in sound reinforcement and playback systems. The line includes models designed for low and high impedance speaker loads. The units are ready to be put to use right away without a complicated set-up process.
The CL Series is a line of speakers aimed at the audiophile offering high-quality sound for an exceptional home or office experience. An aesthetically appealing design coupled with superior performance makes this an ideal product for any type of space. The speakers come in black or white, and boast 19 different models.
Featuring DualDrive technology, the SN Series integrated mixer-amplifiers deliver outstanding performance and a multitude of features. The SN2108 is specifically designed for warehouses, office spaces and other venues fitted with simple sound systems. Whereas, the SN2408 is ideal for use in conference rooms, hotels or other spaces fitted with distributed sound systems.
The TN Series combines the latest advancement in technology while keeping to a minimalist design. The TN6232 Feedback Suppressor is a unique, state-of-the-art product. It’s the perfect solution to feedback problems that often plague live performances. The TN6232 is fully automatic, and works in any venue with a sound reinforcement system.
The MA6000 series is the most powerful integrated mixing and amplification solution on market. It boasts automatic mixing, dual-channel amplification, and many more features. The MA4000 series is an elegant integrated mixer-amplifier solution for a variety of installation applications. It’s energy efficient and user-friendly.
SL Series on-wall loudspeakers are elegantly designed and deliver superior sound quality to any space. Behringer developed a wide frequency response with its exclusive waveguide technology. Durability, style, and professional-grade performance - Behringer takes wall speakers to a whole new level.
The ST Series is an in-ceiling speaker line that offers a rich, seamless sound in an appealing exterior shell. Concentric drivers are the source behind its broad frequency response and exceptional dispersion. These speakers are ideal for conference centers, hotels, casinos and more.
Each product undergoes rigorous testing and research to ensure lifetime dependability, exceptional performance, and the best features available.
dbx Offers Software Update For DriveRack PA+ Loudspeaker Management System
dbx has announced that it is offering its Software Version 1.1 update for its dbx DriveRack PA+ Loudspeaker Management System. The dbx DriveRack PA+ makes it easy to set up and optimize a portable PA system with its exclusive Set Up Wizards that guide users through system setup with step-by-step instructions.
Utilities including Auto Level Wizard, Auto EQ Wizard, automatic feedback suppression and many more enable even inexperienced users to make their PA to sound like it was tuned by a pro.
The software version 1.1 update provides the latest tunings for JBL loudspeakers and Crown Audio amplifiers including JBL PRX Series loudspeakers, Crown XTi Series and XLS Series amplifiers.
The update can be downloaded free of charge from http://www.dbxpro.com. The downloaded Wizard-enabled web-updater will check for the latest release and walk the customer completely through set-up and will notify the user of future updates as well.
The DriveRack PA+ is the world’s most popular loudspeaker management system and enables users to optimize the performance of loudspeakers and amplifiers in a portable sound reinforcement system by precisely adjusting crossover points, speaker levels, EQ settings and other parameters.
First Presbyterian Church Deploys Altinex Control Solutions
The First Presbyterian Church in Baton Rouge, Lousiana, has a storied history that dates back to 1827. As the church has grown, so too has its desire to remain cutting edge and relevant to its congregation. In keeping with this tradition, the church recently deployed both an impressive AV setup and a remote door locking control system.
In each case, the underlying technology behind the design and operation of both systems is dependent upon state-of-the-art equipment from Altinex.
IT Consultant Dean Cooper, also from Baton Rouge, served as both the system designer and integrator for the two projects. Cooper discussed the challenges the church faced that led to the use of the Altinex equipment.
“Previously, each door of the church had an override button to lock and unlock it,” explained Cooper. “With 9 access points, it was very difficult to secure the building and equally time consuming to open it up.
“Church management wanted a solution that provided centralized control of this process as well as the ability to manage individual entrances.
“The church also wanted a series of video displays—both in the sanctuary and at additional locations throughout the church—to help create a more engaging worship experience and that would provide the ability to monitor services from positions outside the sanctuary.
“In both cases, Altinex Neutron series controllers and AVSnap software provide the infrastructure that governs each system.”
Cooper reports there are five projection screens in the sanctuary: two stationary screens along the back wall provide lyrics and related content for the choir and musicians while three screens reside up front.
There is a central drop down screen above the stage / altar area and one screen each on the left and right sides that swing out from the side walls. Additionally, there are four remote simulcast video display points situated throughout the church to facilitate viewing of activities in the main sanctuary.
“The entire AV system was designed using AVSnap,” Cooper explained. “AVSnap is a terrific program that not only makes system design intuitive; it also serves as the engine that enables the system to operate. Further, this software made it easy to create the interface for the CP450-008 touchscreen controller that enables one to manage the system.”
“The AV system uses an Altinex CP500-100 Neutron Controller,” Cooper continued. “With the ability to control bi-directional devices via RS-232 in addition to its support for IR (infrared), relay-based, and sensor devices, we were able to create a system that enables video signals to be distributed individually to each screen in the sanctuary as well as being able to place the same video signal on all screens.
“The Neutron controller is also the device that transmits commands for the various motorized functions of the screens.”
While the Altinex CP500-100 Neutron Controller, CP450-008 touchscreen controller, and AVSnap are the most notable components in the AV system, Cooper also acknowledged a wealth of additional Altinex signal management solutions that helped make the entire system possible.
“We used a lot of Altinex gear,” he added. “We used TP115-110 and TP115-111 Video + Audio UTP transmitters and receivers, an MT110-102 audio matrix switcher, two MT106-103 video scalers and a lot more. Every aspect of the system’s control and distribution was handled by Altinex equipment.”
For the centralized door locking and unlocking system, Cooper used AVSnap to design and run the system. This time, he used the Altinex CP500-110 Neutron controller (the smaller version of the CP500-100) and an Apple iPad for the touchscreen controller.
“For this project, the ability to arm and disarm doors while walking the complex was essential,” Cooper points out. “Again, AVSnap made the design process easy and the Neutron controller handles the transmission of open and close (on/off) relay signals that communicates with the locking system. Finally, the church has a means of securing the entire building quickly and easily.”
Before turning his attention to the business of the day, Cooper summarized his Altinex experience.
“The AV and door locking control systems that we assembled have made a really positive impact here at the church,” says Cooper. “AVSnap made the creation of the end user interface fast and painless and it also provides the infrastructure that enables all this equipment to work together.
“Everyone is ecstatic with the results of both systems. I’d also like to point out that Altinex customer support services are first-rate. When I had questions, everyone was very helpful and responsive. Working with Altinex was a pleasure.”
Posted by Keith Clark on 06/19 at 10:24 AM
Accord Productions Relies On Lectrosonics
The production crew of Miami, FL-based Accord Productions captures audio with a high level of speech intelligibility and natural sound quality by depending on Digital Hybrid Wireless technology from Rio Rancho, NM-based Lectrosonics.
With offices in Miami and Ft. Lauderdale, FL, Accord Productions provides production, post production, and digitizing services to the film and video industry. Its co-founder and vice president, Rocky Wyler, typically serves as the director of photography on location and also performs double duty as the company’s technology chief.
In this capacity, he is always on the lookout for new and better ways to keep the company at the cutting edge of developments as they relate to field production. A long time Lectrosonics enthusiast, Wyler reflected on a recently completed project and the impact his firm’s Lectrosonics equipment made.
“I’ve been a fan of Lectrosonics gear since the early 90’s when I first purchased some CR185 receivers and high band transmitters,” states Wyler, “so I have a pretty long history with the company. For much of our work in recent years, we’ve used UM400a beltpack transmitters with SR dual-channel slot mount ENG receivers.
“Just recently, we began working with Lectrosonics’ SMQV super-miniature, dual battery beltpack transmitters. These came in particularly handy on a new reality TV show called Ocean Models. Rounding out the gear for this project, we also had several of the company’s T4 IFB transmitters and R1a beltpack IFB receivers.
“At any given time, we had 4-5 producers on the set and each one was hooked up with the IFB gear.”
Ocean Models follows 15 international models that come to Miami to work with a new, high profile modeling agency. They were housed in a 10,000 square foot mansion on South Beach and provided with all the amenities most models never get to experience.
“There were several days where we had a good 16 – 18 mics going among the three audio guys—each of whom was equipped with digital 8-track recorders,” said Wyler. “Sometimes, the guys would have to follow the girls in opposite directions and when they split up, range became a huge factor.
“I was really pleased with the fact that our Lectrosonics gear handled this challenge beautifully. This would not have been the case with several competing wireless systems I’ve encountered.”
Wyler also reports that Lectrosonics audio quality, build quality, and reliability are equally important factors.
“Audio quality is exceptional. I love the fact that there are none of the annoying artifacts one frequently experiences with wireless systems using compandors. I’ve also been very impressed with the build quality—particularly of the new SMQV’s.”
“We used two SMQV transmitters on some of the models,” Wyler recalls. “These units are great. They’re really small and this made them easy to conceal when the girls were wearing skimpy outfits.
“I also discovered another important benefit of these transmitters. After a short while, the girls got very accustomed to wearing the transmitters and they started turning them off to make comments among themselves, which sometimes really fouled us up.
“With the SMQV’s, we locked them out so as not to interfere with our side of the production.”
Wyler was so impressed with the SMQV’s robust performance and compact form factor that he has since ordered several more units.
“As a result of our experience using the SMQV’s on this project, we are currently in the process of acquiring several more for all our reality show work. We will, of course, continue to use our UM400a’s in our industrial work. Based upon the success of our Lectrosonics equipment with this project, we will never have any other brand of wireless transmitter on our reality projects that aren’t Lectrosonics SMQV’s.”
Prior to turning his attention back to the business of the day, Wyler offered these final thoughts. “Our Lectrosonics equipment has served us extremely well over the years. The audio quality and range are excellent and the reliability is second to none.
“We have four in-house audio guys and I assure you they’re not very easy on the gear. Our Lectrosonics equipment is the only gear that seems to survive long term. I can’t imagine working in this business without it.”
Posted by Keith Clark on 06/19 at 09:18 AM
Bag End Subwoofers Deliver For BYU-Idaho Center
When the Brigham Young University - Idaho Center was opened it was home to one of the largest production theatres in North America built for the primary purpose of supporting weekly student devotional services.
The venue features 15,000 seats and a stage measuring 108-feet wide and 60-feet deep and a new sound system that delivers a warm, intimate sound experience to every member of the audience.
Essential to the success of the space was the performance of the new center’s 5-manual Rodgers digital organ which was installed by Heritage Church Organ Company. Diversified Systems was tapped to provide the new sound system which would be key to the organ’s success.
Diversified Systems worked closely with audio-video consultant Ken Fause from Auerback Pollock Friedlander and resident BYU-Idaho engineer David Mann on the project.
The new sound system includes 8 Bag End Infra-MXB dual integrators, 16 Bag End S21E-CUS self-powered subwoofers with loop-through XLR Inputs and Power-con loop-through on the cabinet for the dynamic low-end the organ required. Completing the system are 2 DiGiCo SD7 mixing consoles, NEXO GEO D10 line arrays, fill speakers and amplifiers, and Yamaha DME-64 processors.
“We had a specific vision in mind when we chose these Bag End subs,” explains Fause. “We were looking for a wave front of sub-frequency energy that would go down to 8Hz.”
To place the subs in an optimal location to produce that “front wave” of organ sound, yet not be visible to the audience, they were installed in a cavity created along an existing concrete bulkhead beneath the stage.
“One of the challenges of the project was ensuring that the processing equipment ahead of the self-powered subs would be capable of passing 8Hz,” notes Prager. “In addition we needed to make sure that the considerable sub-frequency energy under the stage would not cause the platform itself to vibrate.”
“This entire project entailed an enormous amount of planning and precision execution, ” says Fause, ” and I can’t speak highly enough of the degree of collaboration and teamwork among all involved that resulted in such great success.”
The success of the project was confirmed shortly after completion when a retired organist from the University stopped by unannounced, played the instrument, and commented that it was the closest to a pipe organ that he had ever heard. This was strong praise from him, considering that the University is also home to a world-class Ruffati pipe organ.
“In addition to organ concerts and devotional services,” David Mann points out, “The theatre has also hosted events like “Pioneers and Patriots”, which included an F-16 flyover. At these special times, we can access the subs for that extra depth of sound that brings the event to life.”
The state-of-the-art venue at this Church of Jesus Christ of Latter-day Saints university provides seating for the entire student body and community guests at regular weekly devotionals, as well as special interest events of a secular nature including guest speakers, commencement services and the performing arts. All of these may also be recorded or broadcast live over the BYUtv network, which has an international reach through many leading cable and satellite service providers.
Perfectly Angled Desktop Monitor From Dynaudio Professional Available Now
Dynaudio Professional introduces the DBM50 – the perfect active desktop monitor featuring a 7.1” woofer and a 1.1” soft dome tweeter.
Designed for desktop use, the monitors offer a perfectly angled front, a waveguide around the tweeter and an optional level controller that does not compromise the level interrelationship between speakers.
Each and every DBM50 is handcrafted in Denmark with attention to even the tiniest detail. More than 20 years of expertise in speaker design, development and manufacturing guarantees a set of monitors that go the extra mile to recreate even the smallest and most subtle details of any recording or production.
The DBM50 comes with the option of adding a sleek controller that puts the user squarely at the helm of volume control in any situation. Levels can be set and manipulated with precision and ease, completely independent of the computer or workstation in use. The DBM50 controller provides perfect tracking, which guarantees spot-on stereo imaging with unprecedented precision.
DBM50 Main Features
• Perfectly Angled for Desktop Mixing
• Every Driver Hand-built in Denmark
• Optional Master Volume Control
• 7.1” Woofer / 1.1” Soft Dome Tweeter
• 50+50 Watts
• 117 dB SPL
• Frequency Range: 46Hz - 21kHz
• Dimensions: 230 x 348 x 335 mm / 9.1” x 13.7” x 13.2”
• Weight: 7.2 kg / 15,9 lbs
Available now in the EU and in July 2012 in the US. Prices are: USD 499 MAP each; EUR 499 SSP each; and GBP 415 SSP each. The optional volume controller is priced: USD $69 MAP; EUR 69 SSP and GBP 59 SSP.
Posted by Keith Clark on 06/19 at 06:24 AM
Monday, June 18, 2012
A Practical Guide To Good Bass: Part 1, Acoustical Concepts Of Subwoofers
In sound systems, it would be terrific if loudspeakers worked like spotlights: find the loudspeaker boxes with the right directional patterns, aim them where you want sound to go, and you’re done. Of course, that’s not the way it works, especially for bass.
Ordinary bass loudspeakers are very nearly omnidirectional over their working ranges, but when you stack up a few of them, the pattern becomes more directional and more complex. Imagine if lights worked that way—a bare light bulb would illuminate the whole room, but four of them in a row would only light up some parts of it.
To make things worse, when you use multiple woofer stacks—stage left and stage right, for example—it produces wave interference (also called “comb filtering”), causing peaks and nulls in different places in the room at different frequencies. If light worked that way, then when you lit up a room with two white lights spaced some distance apart, the room would be illuminated with a rainbow of different colors.
Even beyond that, there’s the problem of reverberation, which adds its own kinds of confusion and coloration in the time dimension. That effect that doesn’t even have a parallel in lighting.
In the face of all these phenomena, how do audio professionals design subwoofer arrays and drive schemes that provide required qualities of coverage and fidelity?
If we succeed, then:
• The bass will be clear and will have constant tonal balance over the entire listening area.
• The bass sound level will be in correct balance with the midrange and high-frequency over the entire listening area.
• Negative effects of reverberation and reflection will be minimized.
• Efficiency of the equipment (sound power output per unit cost) will be maximized.
This article offers concepts and techniques for getting good bass. Our focus will be the frequency range from approximately 20 Hz to 150 Hz.
Just about everything having to do with loudspeaker array acoustics is relative to wavelength. A box or array is “large” if its dimensions—or some of its dimensions—are more than about 1.5 wavelengths across. A dimension is “small” if its dimensions are less than about a third of a wavelength.
Here are some typical wavelengths:
For normal air temperature, pressure, and humidity, the formulas for wavelength are:
Basic Directivity Rule
For ordinary sound sources, directivity is inversely related to dimension. If an object is small, its directivity is wide; if large, its directivity is narrow. (See Figure 1) Remember that “small” and “large” are measured in wavelengths, not feet or meters.
The basic directivity rule applies independently in the horizontal and vertical planes. For example, a horizontal line of subwoofers might be large horizontally and small vertically. Therefore, its directivity would be narrow horizontally and wide vertically, as shown in Figure 2.
Multiple Sources and Lobing
Many, if not most, subwoofer installations use two separate arrays on opposite sides of the stage. Sometimes these arrays are stacked on the floor, sometimes they’re flown.
Either way, the multiple sources exhibit what physicists call “wave interference”, and what audio people call “comb filtering” or “lobing”.
Figure 3 shows the directivity of a single EV Xsub woofer at 50 Hz. In this example, size of the stage is 40x20 feet. The red trace is the polar pattern. Circles are 6 dB apart. The Xsub is essentially omnidirectional.
Figure 4 shows what happens when another Xsub is added at the opposite side of the stage. The result is very different—and not better!
Because the woofers are omnidirectional, everyone in the room hears both woofers. However, the distance from each woofer to the listener is different, except in the middle. Where the distance difference equals an odd multiple of a half-wavelength, the sounds from the two woofers cancel, and the listener hears no bass, at least not directly from the woofers.
These lobes will produce uneven bass tonal balance and level in the venue. In indoor venues, the tonal balance problems are partly masked by reverberation, but the lack of clarity remains. Outdoors, there is no reverberation, and the problem is usually quite obvious.
Figure 5 shows performance of two practical cases - groundstacked rows of subwoofers, and flown subwoofer line arrays.
The only region that is lobe-free at all frequencies lies along a line running directly out from center stage. Along this line, the bass is strongest and clearest. This is the familiar “power alley” effect that makes the bass sound very good at the mix position, but does not give the mix engineer a good idea of what the rest of the audience is hearing.
The best solution for lobing problems is to use a single center cluster instead of separate left-right stacks. This works for both horizontal and vertical arrays. However, it is not often a practical solution for staging and rigging reasons.
When left-right stacks are used, lobing problems can be reduced using stacking, beamforming and/or gradient woofers. In all cases, the idea is to minimize interference between the coverage areas of the two stacks.
Beamforming is a technique by which the sound wave emitted by a large array can be aimed and shaped. In a beamformed array, the loudspeakers are driven separately (or in small groups), and each drive signal has its own delay and level.
Figure 6 and Figure 7 illustrate a typical effect of beamforming on a typical medium-sized subwoofer array. The illustrated array is four EV Xsub subwoofers. Figure 6 shows the array with no beamforming. In Figure 7, the delay values are chosen to direct the bass radiation offstage. This is a typical technique for increasing side coverage.
Beamforming only works on arrays that are large (as defined above). Controlling directivity of small arrays requires gradient techniques, which will be addressed in my next installment of this article.
The term “shading” means modifying array drive parameters for the elements on or near the ends of the array. “Gain shading” means adjusting—specifically, reducing—the drive gain for one or more elements at either end of an array.
For long arrays, shading takes the form of a gradual tapering of gain from 0 dB to about -6 dB over the last two or three elements at each end. The effect of the shading is to make the coverage pattern more regular and less frequency-dependent.
Next time, I’ll be discussing various woofer array types and applications.
NOTE: The polar patterns illustrated in this document have all been produced by the Electro-Voice LAPS 2.2A line array design program. Starting with release 2.2A, LAPS includes a subbass pattern modeling page.
Jeff Berryman served as the director of Jasonaudio, a touring sound company based in Canada, and is a senior scientist with Electro-Voice.
Related Articles by Jeff Berryman:
What Really Defines Good Bass In Sound Reinforcement?
Discussion & Analysis Of A Variety Of Bass Coverage Patterns
AKG Discreet Acoustics Modular PLUS Series Delivers For Conferencing And Presentations
With a continued focus of providing the highest quality and most versatile microphones available, AKG announces its latest addition to its installed systems – the Discreet Acoustics Modular PLUS Series.
With a wide range of goosenecks and installation modules available, the Discreet Modular PLUS Series offers optimal adaptation for all types of room setups and speakers, with quick microphone capsule exchange.
The reliability stemming from the models’ LED Ring underscores the ability to reduce the risk of operating errors, sturdy material to reduce fatigue and improved protection from signal block outs. The LED Ring uses special circuitry to operate off standard phantom power, as two separate leads carry supply voltage and provide extra shielding to the audio signal.
The Modular PLUS Series’ interface module connects the high-quality gooseneck to the phantom power source, which adds flexibility to all mounting modules. The self-cleaning connector is reliable, inconspicuous and safe – allowing for simplified and cost-effective microphone replacement.
The goosenecks themselves are tested under extreme circumstances, bent and twisted into extreme shapes, ensuring their quality and flexibility.
“AKG has specialized in developing, designing and manufacturing quality microphone capsules for more than 60 years and the Discreet Acoustics Modular PLUS Series is a testament to the continued strategy to offer the best in sound in any mic’d application,” stated Thomas Giczy, Business Development Manager Installed Sound and Conferencing, AKG. “The variety offered through the Modular PLUS Series, from the power offerings to the mounting and capsule modules, is the best in class and will provide optimum audio for videoconferencing or presentations around the world.”
The CK43 supercardioid condenser capsule offers users a 95-degree pickup angle, ideal for situations where unwanted noise pickup is a concern.
The CK49 is a reference condenser capsule with an 80-degree pickup, with clean, off-axis response. It is ideal for use with inexperienced speakers, focusing on the voice when the speaker is distant, and reducing pop if close to the mic.
AKG’s Gooseneck GN155M is a 155cm module with a heavy, shock-mount floor stand that works perfectly as a stand-alone unit or on stages placed in front of a large group of instruments or speakers. HM1000M is a reference-hanging module used to fly mics from the ceiling to record or reinforce music or speech in houses of worship, theatres or conference halls.
AKG’s PAE M reference powering module offers the phantom power for fixed and mobile installation, providing a gold-plated, 3-pin XLR connector. Its wide voltage range fits most mic mixers. PAESP M is a programmable power module for fixed and mobile installation, fitted with a unique binary coded decimal switch to recall operating modes.
PAESP M’s noiseless mic switch reduces its level by 26dB, avoiding the irritating crackling sound when phantom power is interrupted. The PAE5 M provides a 5-pin XLR connection allowing audio signal and central voltage to be fed separately.
The four different powering modules, five mounting modules and three capsule modules combine and add up to a total of 60 different microphones combinations.
Posted by Keith Clark on 06/18 at 04:15 PM
Symetrix Edge DSP Installed At One Firefly’s New Headquarters
When it came time to move into a new office space, One Firefly, LLC seized the opportunity to turn its workspace into a cutting-edge demonstration of the integrated systems it helps homeowners, commercial clients and electronic system contractors design and install.
The Hollywood, Florida-based firm is multifaceted and provides a variety of services offered under its three Firefly brands. Firefly Design Group provides system design, documentation and consulting services specializing within the integrated building technology space.
Firefly Creative is a full-service marketing and public relations agency that caters to the custom electronics industry’s member contractors and manufacturers.
Firefly Programming is a full service control system programming company.
For the flagship demonstration, Firefly Design Group senior systems engineer Mike Harrell chose Symetrix’ new SymNet Edge DSP hardware, which features a powerful open-architecture topology, modular I/O counts and types, and next-generation Dante audio bus networking, to deliver sophisticated audio processing and routing with full Crestron control system integration.
At One Firefly’s new headquarters, each of six office zones demonstrates different aspects and possibilities that will expand the horizons of its clients.
“We regularly have visitors from integration firms, end-clients and members of the design trade through our space,” states Ron Callis, One Firefly CEO. “We find it extremely helpful to show off the technologies offered by Symetrix and other leading manufacturers.”
Firefly Design Group’s Mike Harrell further explains, “Many of the A/V technology solutions that are aimed at the residential market are quite limited and lack the flexibility needed to create well-tuned and high performing systems. We’re excited to demonstrate SymNet Edge because it has all the right specifications – including powerful DSP, lossless Dante bus networking, customizable I/O, and seamless integration with either Symetrix or third party user interfaces – at a price that allows an integrator to make a profit.
“We’re really showing off the tremendous capabilities of the SymNet Edge system at our new offices so that people can see it in action.”
Three 1-rack space SymNet Edge Frames, networked into a single functional unit via Ethernet cables conveying near-instantaneous Dante bus audio, supply the audio processing for the entire facility. Each SymNet Edge Frame accommodates up to four I/O card slots, which may be fitted with four-channel analog inputs, analog outputs, digital inputs, or digital outputs.
Currently, One Firefly’s system is configured with twenty analog inputs and twenty analog outputs. The system’s varied inputs include computer outputs from around the facility, microphones, iPod docks, Blu-Ray players, and Apple TV. Crestron MC3 and DM MD8x8 processors integrate all user control into one cohesive structure. Crown CT-series amplifiers power all the passive loudspeakers in the facility.
Of the various demonstration spaces, One Firefly’s new conference room is the most elaborate. A surround sound system composed of active Genelec AIW25 left-center-right and AIC25 rear loudspeakers, and two 5041A subwoofers can convert the space into a stunning multimedia center and demonstration home theater.
The SymNet Edge provides unique processing for the surround system that is unavailable in consumer-grade surround processors. It provides a program-sensitive cutoff for the subwoofer content that effectively delivers left- and right-channel bass, in contrast to the usual fixed-cutoff, center-mono channel. More card options for Edge are currently in work.
Acoustician Michael Chafee consulted on the acoustical treatment of the new space, which included considerable work in the conference room. In addition, the SymNet Edge system provides comprehensive room tuning.
“Because we were dealing with existing construction, we weren’t able to arrange the physical space exactly as we would have liked,” said Harrell. “Nevertheless, good acoustical treatment and a full complement of room-tuning tools in the SymNet Edge system compensates quite effectively.
“It actually ends up being a better demonstration this way, because no project – no matter how high-end – is free from constraints. Here, we present strategies for working within a less than perfect environment.”
The goings on in the conference room, or any room for that matter, can be watched and listened in on from any other room. User control of this and every other system function is accomplished by Crestron TPMC-3X handheld WiFi touch-panels, TPMC-4SMD fixed-position touch-panels, and Xpanel computer-based interfaces.
In addition, Symetrix ARC-WEB, which provides password-protected system control that is fully customizable by the integrator, will be available for use on employees’ smartphones.
For Harrell, part of the attraction of SymNet Edge is its embrace of the Dante audio bus.
“I’ve been following the development of Dante for some time now, and it offers a number of important advantages for our clients,” he said. “For one, it is easily expandable up to 128 channels of lossless audio. That’s critical in the residential market, where we typically use more channels than the commercial market because every source is stereo or surround.
“The fact that Dante is nearly instantaneous is exciting.” Harrell programmed the system using SymNet Composer software, which he reported was even easier and more intuitive than the already easy and intuitive SymNet Designer software that preceded it.
The remaining demonstration spaces, which include CEO Ron Callis’ office and the sales, creative team, engineering, and accounting offices, show off different combinations of acoustical treatment and loudspeaker, video, computer, and lighting technologies.
Posted by Keith Clark on 06/18 at 01:24 PM
Atlas Sound Debuts DSP2210 & DSP2212 Digital Processor And Amplifier
Atlas Sound DSP2210 and DSP2212 digital sound masking/paging systems are self contained, digital signal processors with integral amplification designed to efficiently route and mix masking, paging, and background music sources. Applications include speech privacy and general paging for office spaces, health care campuses and secure government facilities.
Masking source is completely random and non-repeating (up to 215) hours with EQ adjustments programmable per output zone. Both models include dual channel Class-D amplification rated at 25W/channel (@ 70.7V) and a built in telephony interface simplifies paging set-up.
The system is expandable up to (32) systems (64 zones) with primary and secondary assignment in a zone page dialing plan (2-digit DTMF) with “All Zone” and “Group zone” pages simply configured via the GUI. A powerful, fixed architecture DSP provides equalization, dynamic and routing priority control for all input sources as well as line level and amplified outputs.
Model 2212 includes AVB (Audio-Video Bridging) network interface allowing paging and BGM sources to be shared between multiple DSP8807’s or DSP2212’s.
“The DSP2210 and DSP2212 are the other two new products in the sound masking category that we are releasing this year”, said Steve Young VP of Sales & Marketing.
He continued, “the DSP2210 and DSP2212 are feature rich sound masking processors that can be used in small to medium applications. By themselves they are extremely useful but when the DSP2212 is used on the same network as the DSP8807 our integrators can truly handle any size sound masking application.”
Auralex Unveils QuadFusor Sound Diffusor At InfoComm 2012
At the InfoComm 2012 show in Las Vegas, Auralex Acoustics introduced the QuadFusor sound diffusor, combining four of the company’s MiniFusors and arrays them in an attractive 2-foot-by-2-foot pattern.
The Class A fire-rated acoustical diffusor is suitable for commercial spaces and can be dropped into a ceiling grid or mounted to a wall or ceiling.
The QuadFusor’s surface-variable design includes a proprietary ledge and rear cavity that accommodate the insertion of a rigid substrate such as Auralex PlatFoam or acoustical fiberglass, thus improving the device’s diffusion characteristics and adding significant low-frequency trapping.
The QuadFusor can easily be installed in new or existing construction. The QuadFusor is Auralex’s latest addition to their complete line of acoustical treatment solutions, perfect for contractors and system integrators at any budgetary level.
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