Article

Monday, February 06, 2012

Dynamics Of Product Procurement In The Commercial Electronic Systems Industry

The latest Market Intelligence Briefing (MIB) report from the National Systems Contractors Association (NSCA), Channel Trends and Issues: Dynamics of Product Procurement in the Low Voltage Commercial Electronic Systems Industry, examines the continually evolving product procurement opportunities many systems integrators face in today’s way of conducting business.

The report provides a distinct difference in the varying methods – including sales representatives to two-step distributors – and outlines the trends of purchasing, product sourcing, dealer business programs, and how systems integrators evaluate their supplier sources.

An evolving distribution channel is causing systems integrators to make decisions on product procurement, providing challenges to the traditional marketplace in the low voltage systems channel.

As businesses streamline and become more efficient, the number of brands of products carried and installed has become more specific, driving the relationships between suppliers and integrators to become an important factor of the distribution model. 

The relationship between these suppliers, be it from manufacturers (nearly 50 percent of the respondents purchased gear directly from 6-25 manufacturers) or distributors, (76 percent of integrators purchase from 3-10 distributors), is becoming more important.

However, in 2007, integrators purchased an average of 38 percent of their equipment/supplies through two-step distributors, and in 2011 only 34 percent of total equipment/supplies purchased came from distributors.

Interestingly, smaller firms who procure more products from distributors cannot compete with minimum order and annual purchase requirements, allowing two-step distributors to pave a way for smaller firms to be viable and competitive.

Further, the report shows that some integrators have purchased equipment from distributors to gain advantages such as special pricing, reduced or free freight and other incentives despite having dealer relationships.

Understanding the benefits of a dealer business program are critical to the relationship regardless of which distribution model you choose. Of most importance to the integrators were product/technical training and support and “live” customer service (aka, talking to a real person).

Price also proved to be an important factor, but training and customer service remain the top two factors when determining your partners and providers in business. A strategy applied to all factors of your business from sale to installation to maintenance. 

Beyond the business programs, integrators were asked to rate their favorite suppliers, and while there were similar responses, the highly rated distributors featured easy access to “people;” a warranty tied with products, technical training, support; system design assistance tied with a good return policy; and finally sales/training support. 

Of least importance were incentives, mobile apps with technical data and coop advertising or “key city money” programs.

The report also shows a majority of integrators prefer field sales reps for audio equipment and for control and interface, security and life safety, telephony, racks, mounts, furniture, accessories, lighting and lighting controls equipment a more direct link to the manufacturers is preferred. Two-step distributors ranked higher in data cabling, security and life safety, telephony and other accessories.

Of other importance is the difference from 2007 to today in the ratings of both local sales reps and distributors in general. Reps in general were rated higher in 2011, and while the ratings for distributors also were higher in 2011 than in 2007, sales representative still ranked higher than distributors.

More detailed information is included in the report showing the important factors used in rating the various distribution models, dealer business programs, how suppliers are chosen and the preferences of product procurement.

NSCA’s MIB reports provide members with current data on key industry issues complete with statistical results, interpretation, implications, market knowledge and implementation goals. NSCA members can access the full report at www.nsca.org/mib.

NSCA

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Friday, January 27, 2012

Everything You Wanted To Know About Sound Level Meters (SLMs)

The primer: what, how, why, what's available, techniques, applications and more

A sound level meter (SLM) is a device used to make frequency-weighted sound pressure level measurements displayed in dB-SPL.

0.0 dB-SPL is the threshold of hearing, and is equal to 20uPa (microPascals). This correlates to what one would aurally perceive when in a deep cave or in a large anechoic chamber.

Packaged as a single-function handheld test device, SLMs are intended to be held at arm’s length during measurements (to reduce the effects of the body on the measurements) or secured to a tripod stand for more stability.

All SLMs feature an omnidirectional measurement quality condenser microphone, a mic preamp, frequency weighting networks, an RMS detector circuit, averaging circuits, the meter display, AC and DC outputs used to feed other measurement devices or for recording (see Figure 1, below).

Most SLMs have the same set of user adjustments, including SPL range selection, A and C weighting filters, slow and fast detector response, and minimum or maximum SPL.

The SPL range switch provides a balance between minimizing the preamp noise level and measuring a wide range of sound pressure levels.

Most of the commonly available SLMs measure from about 30 to 130 dB-SPL and do this in 3-4 ranges.

 
The more advanced and expensive SLMs feature removable microphones, 1-octave and/or 1/3-octave filter sets, additional weighting filters including B, D and Flat or Linear (no filter), additional detector response options (Impulse and Peak), averaging (over time) and data logging or storage (either on-board, as computer files or both).

Almost all SLMs are designed and specified to perform to one of four internationally standardized levels of accuracy:

 
Note that these tolerances are at 1 kHz, the standard calibration frequency for SPL measurement. In order to ensure the flatness of the SLM there are additional tolerances specified for various frequency bands and microphone classes as well.

Class-0 SLMs are employed primarily to calibrate other SLMs and may be used for very high precision noise measurement in controlled spaces and/or for academic research.

Class-1 and Class-2 SLMs are most widely used by acousticians, sound system professionals, industrial designers/ manufacturers and researchers in academia and government. Measurements made with these levels of accuracy are generally acceptable as evidence in the resolution of legal disputes.

Class-3 SLMs are restricted to noise survey meters and dosimeters.

Microphone Sizes
Most general purpose SLMs are provided with a 1/2-inch free field microphone, permanently attached to the SLM body.

Higher quality SLMs with removable microphones may be outfitted with capsule sizes ranging from 1/8-in to 1-in.

The smaller microphone capsules (1/8-inch and 1/4-inch) have three primary advantages:
—They are capable of higher SPL measurements;
—They remain omnidirectional up to higher frequencies;
—And they present less disturbance of the air due to their reduced physical size (the mic itself has less impact on the measurement).

Larger 1-inch capsules exhibit less self-noise and are therefore best suited to measurement in very quiet spaces, of very low-level noise sources, and of low-frequency energy.

Microphone Classes
One can also choose between three different classes of measurement microphones: Random Incidence, Free Field, and Pressure.

In reality, these three classes of microphone are all fundamentally “pressure response” microphones and are designed to sense pressure - not pressure gradients or particle velocity.

The difference is primarily in how they pick up sound at high frequencies, and this relates to how they are positioned relative to the sound source.

At higher frequencies (where wavelengths become so small as to equal, or be smaller than, the size of the microphone diaphragm) the direction in which the microphone is aimed - relative to the direction of the sound being measured - will have an effect on the accuracy of the measurement.

Random Incidence microphones are intended for use in a diffuse sound field where the sound is arriving from all directions due to a high level of reflections.

This type of microphone must be angled approximately 70 degrees to the sound source in order to yield accurate measurements.

Free Field microphones are designed for use in an open space (free of reflections) and should be held at 0 degrees to (pointed directly at) the sound source.

Pressure microphones are designed specifically for measurements in couplers and closed cavities such as plane wave tubes, ear cavities in dummy heads and for noise measurements in air ducts.

Some SLMs provide a switched correction filter allowing one type of microphone to be used in place of the other.

Note: In general, a “measurement quality” microphone differs from a recording or sound reinforcement microphone in its flat response, the absence of an onboard preamp, and its less rugged construction.

Detector Averaging Time
The standard averaging time choices provided by the majority of SLMs are Fast and Slow.

The Fast setting has a 125milliseconds (mS) averaging time (developed in 1950 to match the ballistics of the moving coil meters used at that time) and is useful for steady state (not dynamic) sound.

For measurement of more dynamic sound (when the Fast setting results in fluctuations of 4 dB or more), the Slow setting provides a 1 second averaging time resulting in much more consistent and stable readings.

It is this setting (along with an A-weighting curve) that is most frequently used for measurement of pop music SPLs.

Some higher priced SLMs also provide Impulse response time (four times faster than the Fast setting) used for extremely dynamic and short term (impulse) sound and peak response time, which accurately responds to signal pulses as short as 50 microseconds.

Frequency Weighting Filters
Because we humans do not hear frequencies in a linear manner (as illustrated in the often referred to Fletcher-Munson curves, aka: equal loudness contours), sound level measurements made with a flat response do not accurately reflect how we perceive sound.

When measuring pop music sound reinforcement systems (with the program signal containing generous amounts of bass energy), broadband readings would be artificially high without the frequency shaping provided by the A-weighting filter.

C-weighting, with its more gradual low-and high shelving filters, is used for very high SPL sound system and noise measurements.

On SLMs without a Flat setting, the C-weighted setting may be used to feed a spectrum analyzer such as Rational Acoustics Smaart for frequency analysis of the broadband sound.

Table 2 below, and then Figure 2 below that, show the frequency response for A and C weighting filters, plus two other weighting filters employed for more exacting and specific noise measurements.

 
All weighting curves are equal in level at 1,000 Hz, the standard reference frequency that SLMs are calibrated to using acoustic calibrators.

Note On SPL Annotation: When communicating or recording (speaking or writing) SPL values, it is necessary to annotate what - if any - weighting curve has been employed. A-weighted SPL is written or stated as “XX.X dBA” and C-weighted measurements as “XX.X dBC”. Such annotation eliminates the need to provide the “SPL” suffix.

The absence of weighting notation implies that a Flat setting (no weighting filter) was used and in this case the suffix “SPL” must be used to differentiate from other, non-acoustic decibel values.

Historical Note: The A, C and B frequency weighting curves were first developed for specific sound levels based on equal-loudness contours.

Because equal-loudness contours were developed from research utilizing pure tones, it later became evident that the weighting curves chosen for SLM measurements at certain levels do not correlate very well to how we actually hear complex sounds.

 
More recently it has been found that the A-weighting curve provides a realistic approximation of how we hear over a fairly wide range of sound level measurements.

Display
With very few exceptions, modern SLM’s are provided with LCD displays with 3- or 4-digit readouts. Most of these provide 1/10-dB resolution except in the case of 3-digit displays when they go over 100 dB-SPL.

Prior to LCD technology, analog meters were employed and these suffered from all the inherent shortcomings of this method of display: slow rise and settle time, susceptibility to damage from pinging (over loading) and overall mechanical fragility.

Another shortcoming of analog meters is the difficulty in establishing stable readings due to the range selecting that is common in most SLMs. One must take the range that is selected and then add or subtract from the meter position accordingly.

Measurements made when the sound pressure level has changed and is out of range are prone to be inaccurate, as well. Some feel that fast impulse noise measurements are easier to read with an analog SLM than with a “digital” SLM.

Both styles of display are difficult to read in dim lighting but some SLM’s feature backlit LCD’s for this condition. And either type of display may be quite difficult to read while at arm’s length if the display size is too small.

Equivalent Continuous Sound Level
Although we live sound folk generally believe that we are able to accurately determine the overall sound pressure level when we view the displayed real time values on our SLM’s, these readings are actually no more than a glimpse, or snapshot, of the varying sound pressure levels that we are exposed to.

Due to the dynamic content of the sounds we normally work with (this applies to both speech and music) and our own human shortcomings, we are unable to mentally integrate the frequently changing SPL’s and determine an accurate mean SPL value.

Research into hearing safety and annoyance and the standards that have been developed from this research are based on the accumulative exposure to sound energy over periods of time.

To this end, integrating SLMs have been developed to provide measurements that are conducted over a selected time period and averaged so that they provide an accurate equivalent energy value, designated as Leq (LAeq or LCeq when weighting is employed).

Integrating SLMs also provide Lmax and Lmin values, and the user can choose the time period that the Leq averaging takes place (normally from several seconds to 24 hours).

More and more organizations and governments are adopting this as a more accurate means for establishing risk of hearing damage, community noise standards, annoyance issues, etc.

Although stand-alone integrating SLMs are considerably more expensive than basic SLM’s, some software is available to provide this statistical averaging from the AC output of any SLM.  and both the TerraSonde Audio Toolbox and Neutrik Minilyzer provide this function along with other SPL measurements and other useful audio system measurements.

Relative Vs Absolute Measurement
Absolute measurements are those made with calibrated SLMs that provide actual sound pressure levels referenced to 20uPa (0 dB-SPL).

Such absolute SPL measurements may be used with and accurately compared to those provided by other calibrated and equal quality SLMs.

Conversely, measurements made with un-calibrated SLMs or those with of low quality (including less then linear frequency response) do not accurately indicate actual sound pressure levels.

SLMs that have been incorrectly user-calibrated or have simply lost their calibration over time also do not provide accurate absolute SPL values.

Relative measurements are simply comparisons between sound pressure levels and do not require absolute calibration nor other “precision” performance characteristics such as a flat frequency response.

Non-calibrated and lower-quality SLMs do provide meaningful comparative measurements as long as the same SLM is employed for these measurements and the measurements are made in the same manner.

Example: A Radio Shack SLM, which is specified as providing +/-2.0 dB-SPL accuracy and which has a less-than linear frequency response, is still able to provide realistic indication of the changes in relative sound pressure levels even though it does not provide accurate measurement of absolute sound pressure levels.

Likewise, the SLM function contained in Smaart may be used “as is” (without calibration) for accurate relative SPL measurement.

One relevant and valid relative SPL measurement that can be made in sound reinforcement work is determining the even-ness of coverage provided by a loudspeaker system.

In this case virtually any SLM is able to indicate any deviations that may exist in the sound pressure levels as the SLM is moved about the coverage area of the loudspeaker system.

In a similar manner we can observe changes in relative SPL as the gain of a sound system is brought up and down and we can accurately determine changes in SPL as a noise source (machinery, for example) is turned on and off.

Available SLMs
As stated previously, SPL measurements made with Class-2 and Class-3 SLM’s provide sufficiently accurate (within +/- 1.0 dB) readings for what we require in sound reinforcement work.

Until recently, SLM devices that met this level of accuracy were prohibitively expensive ($1,200 and up).

Most of the old classic SLM’s are cumbersome to set up and, due to their inherently fragile construction, are seldom used for touring sound or on-site installation work.

Without question the most common SLMs used by live sound folks have been those made by Radio Shack. These appear to represent a very good value, are easy to use and are readily available almost anywhere in North America.

In researching for this article I have found that, along with all of the sound system operators and contractors who own a Radio Shack SLM (or two), there are large numbers of other users including university physics/acoustics and biology departments, municipalities, hi-fi enthusiasts, and theater system installers and property management companies.

And there are at least a few websites devoted to using the Radio Shack SLM for tweaking hi-fi, project studio and sound reinforcement loudspeaker systems and for simple noise measurement.

The original Radio Shack model 33-2050 utilizes an analog meter display and has been in production for the past few decades, and several years ago, the model 33-2055 was introduced, providing a “digital” (alphanumeric) LCD display, recessed and better-protected switches and a maximum/minimum measurement function.

Otherwise, these two models employ the same microphone, base circuitry and battery complement.

 
Alternative SPL Measurement Tools
One alternative to the stand-alone SLM’s described in this article is the SLM function included with some of the better portable RTA’s (real time analyzers) that are often employed for live sound and acoustic measurement.

Models from Ivie, Audio Control, and GoldLine all provide accurate broadband sound level measurement (Class-2 or Class-1, depending on the microphone used) plus octave and 1/3-octave spectrum analysis.

This combination of measurements is very useful for determining both the SPL and the frequency components of the sound/noise under con sideration.

 
Most, if not all, of the current crop of computer-based electroacoustic measurement system provide an SPL function along with their frequency and time-related measurements. Of these, SIM from Meyer Sound and TEF from Goldline are sold with microphones and are calibrated at the factory.

Smaart (any version), SpectraFoo, SysSid, PC-RTA and other similar systems utilize third-party microphones and preamps that must be calibrated by the end-user, using an acoustic calibrator or piston.

Once calibrated, these systems provide very good accuracy and feature a number of variables (weighting filters, etc).

Unfortunately, they are not really “handheld” nor nearly as portable as stand-alone SLMs. And (most importantly) they do not retain their calibration from site to site and therefore require an acoustic calibrator for continued use in measuring absolute SPL’s.

Another product that is a variation of a SLM deserves mention here. SPL “management” systems have been available for perhaps a decade and are directly related to the issues of sound system volume levels.

These simply employ microphones and a software-based SLM system that provides either an obnoxious visual warning or more extreme reactive functions (such as muting of the sound system signal!) when the predetermined SPL limit has been reached or surpassed.

Calibration
In situations where the accuracy of sound level measurements must be recorded and/or verified, it is necessary to calibrate the measurement system both before and after the measurements are made.

Software-based electroacoustic measurement systems that feature an SLM function also need to be calibrated if used for absolute SPL measurements.

An acoustic calibrator provides the standard 94 dB or 114 dB (or both) 1 kHz test tone and should also include the proper size opening or adaptor rings for the microphone(s) you intend to employ.

As is the case with SLMs, calibration devices are manufactured to several levels of tolerance (see table near beginning of article) and they have historically been prohibitively expensive.

Recently there have been several acoustic calibrators introduced that provide very good accuracy for sound system and acoustics measurement.

SLMs may also be calibrated with a pistonphone, but the cost of this device is prohibitively high and the high level of accuracy it provides is not practical for most general sound system related measurements.

Why We Use Them
The simple and snappy answer as to why we use SLMs: so we can know what’s going on.

The need for accurate and repeatable sound level measurement is due simply to the tendency for humans to aurally perceive sound in a very subjective manner. This applies to all aspects of sound perception in the audio field: frequency content, mix “correctness”, system EQ, dynamics, etc.

At some point or another we will disagree on the relative loudness being produced plus these other subjective sound qualities.

Whereas other electroacoustic measurement tools remain very subjective in how we interpret the data they provide, a reasonably accurate SLM provides an irrefutable means to objectively verify how loud the sound is (or is not).

SLM measurements may also be used to verify exactly how much the sound level has been changed (as noted in the section on relative versus absolute measurement).

Anyone involved in live sound system work is aware that there is an ongoing and increasing problem with the issue of volume levels produced in public performance, and specifically, in pop music reinforcement.

It’s wise for anyone involved in this field to become familiar with the actual measured numbers, not to mention the need to continually monitor what we are doing. Issues of personal health and legal liability are an ongoing and increasing concern.

Measurement of unintended noise levels and/or the effectiveness of acoustic treatment are additional exercises that most live sound folks eventually will become involved in.

How We Use Them
For basic every day sound system level measurement, using an SLM is fairly straightforward.

The standard SLM employs a free field microphone and is intended to be held at arm’s length and tipped up slightly towards the sound source.

As you move away from the source and into the reverberant or diffuse field, or when measuring in a multiple source sound field such as on stage, the angle of incidence of the microphone becomes much less of a concern.

When measuring noise levels at installation sites, some care should be taken. If measuring the noise level of a rack room, for example, be sure that the SLM is positioned away from walls, floors and other large boundaries.

Signal-to-noise levels are seldom an issue for loudspeaker system measurement because we can simply turn the system up, more than far enough above the noise floor.

But when measuring the noise from a loudspeaker system (hum, hiss and/or the fan noise that may exist in self-powered systems), or from a mixing console and its power supply, etc., or from other common noises such as HVAC systems, vacuum cleaners, power tools, etc., the unintended noise must be at least 10 dB-SPL lower than the noise being measured.

When measuring and logging levels to help resolve a dispute, both A and C weighted measurements should be provided, as should the distance from the source and any other detailed notes.

Also don’t forget that a non-annotated measurement (“00.0 dB-SPL”) will be interpreted to be flat (unweighted).

General Measurement Guidelines
When conducting sound pressure level measurements there are a few basic rules that apply:

• Keep the SLM at arm’s length, aimed in the direction of the sound source(s) and positioned away from room boundaries. By the way, the mixing surface on a large (40-plus channel) mixing console will effect SPL measurement when the SLM is laid down on the mixing surface or angled against the meter bridge.

• For almost all sound system measurements, use the A-weighting filter and Slow response setting.

• Be sure that you’re measuring within the range that you have selected. SLMs with multiple range positions and those with analog displays, in particular, may provide incorrect readings when the SPL is over/under the selected range.

• Prior to making SPL measurements, ensure that the SLM has been turned on for a few minutes and has reached room temperature.

• Wind and air-blowers will effect SPL measurements.

• Be aware of where you are taking your measurements. For example: if you measure from within the area where the bass energy from the sound system has combined (aka “power alley”) or within a standing wave null, the readings will be non-representative of the SPLs for the majority of the audience.

Tom Young is principle consultant for Electroacoustic Design Services in Connecticut, and he has designed hundreds of systems for churches and similar spaces. Tom’s also the moderator of the Church Sound Community Forum here on ProSoundWeb.

More articles by Tom Young on PSW:
Time Is On Your Side (If You Want It To Be) With Sound System Alignment
Microphone Techniques For Drums In Contemporary Worship Environments
The Aux-Fed Subwoofer Technique Explained

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Thursday, January 26, 2012

NAMM 2012 Show Central: Daily Ongoing Live Coverage

All of the latest from Anaheim...

Welcome to ProSoundWeb’s ongoing coverage for the NAMM 2012 Show.

Held January 19-22 at the Anaheim Convention Center, the show drew more than 95,000 attendees from the world of professional audio and music, coming from more than 100 countries.

The show floor hosted exhibits from 1,400-plus manufacturers, with hundreds of new products expected to make their debut. NAMM also provides an ever-growing slate of educational courses and programs.

In addition, the show offered well over 100 live performances and events both on-site and in venues proximate to the convention center.

A couple of interesting notes:
—This was the 110th NAMM Show, making it one of the longest running trade shows in the U.S.
—The show annually generates more than $70 million in revenue to the Orange County economy (Source: calculated using Trade Show Week formula of economic impact)

PSW is continuing to provide updates from the show. Be sure to check back here often.

NAMM 2012 Show News
New Board of Directors Elected During NAMM 2012 Show
110th NAMM Show Reaches New Record Number Of Registrants

New Products

Loudspeakers
Peavey PVX Active & Passive Loudspeakers
On Point Audio OPA28 NP High-Output, Dual 8-Inch Loudspeaker
JBL Professional PRX400 Series Portable PA Loudspeakers
Yamaha DXR Series Active Loudspeakers
Electro-Voice ZXA1-Subwoofer
D.A.S. Audio Action Series Of Active & Passive Loudspeakers
JBL Professional VTX Line Array Series
Spectr Audio S Series Compact Active & Passive Loudspeakers
High-Power Loudspeakers Join Eminence Professional Series
On Point Audio ACTIVE Loudspeakers With Powersoft Amplifiers
Public Beta Version Of JBL HiQnet Performance Manager Software

Consoles/Mixers
PreSonus StudioLive Mixers With Smaart System Analysis Tools
Peavey PVi 8500 & PVi 6500 Powered Mixers
Yamaha MGP12X And 16X Analog Mixers
New Op-Amp Design For Mackie Mixers
Soundcraft Si Compact V2 Software
Mackie DL1608 16-Channel Digital Mixer With iPad Control
PreSonus QMix App: Monitor Mix Control Via iPhone/iPod Touch
DiGiCo UB MADI
Behringer iPad Mixers
Allen & Heath ZED-16FX and ZED-18 Multipurpose Mixers
Roland Systems Group VR-3 A/V Mixer
iConnectMUSE Palm-Sized Digital Audio Mixer For iOS Devices
Allen & Heath GLD Live Digital Mixing System

Microphones
Lauten Audio FC-387 Atlantis Condenser Microphone
Lavaliers, Earset To For Shure Microflex Microphone Line
Headset Option For DPA D:Fine Series Microphones
Audio-Technica AT2005USB Cardioid Dynamic USB/XLR Microphone
TELEFUNKEN M81 Universal Dynamic Microphone
Audio-Technica Limited Edition ATM25 Instrument Microphone
Audix Band Packs Microphone Packages
TELEFUNKEN ELA M 260 Tube Mic Stereo Set
CAD Audio Updated E300S Condenser Microphone
Audix FP QUAD Drum Microphone Pack

Wireless Systems
AKG WMS 40 MINI 2 Dual Wireless Microphone System
Shure ULX-D Digital Wireless System
Sennheiser XS Wireless Series
AKG DMS 70 Digital Wireless Microphone System

Processors
BSS Audio Soundweb London BLU-805 And BLU-325 Processors With AVB
Aphex EX•BB 500 Series Module With Aural Exciter & Big Bottom Processors
Eventide 2016 Stereo Room And Omnipressor Plug-Ins

Amplifiers
Crown Audio I-Tech DriveCore Series Multichannel Power Amplifier
Crown Audio HiQnet Band Manager 2

Monitoring
AKG IVM4500 In-Ear Monitoring System
Pivitec e32 Personal Mixer With 32-Channel Ethernet AVB Capability
Sensaphonics Upgraded IEM line With New Cable, “Crystal” Colors
Sony MDR-7550 In-Ear Monitors
Aviom Pro16 Personal Mixing Systems
Future Sonics mg5pro Ear Monitors
POSSE Audio Personal On Stage Sound Environment System

Stage/Studio
“Dangerous Source” Portable Desktop Monitor Controller From Dangerous Music
Radial Engineering Firefly Tube Direct Box
Behringer FIREPOWER FCA610 & FCA1616 Recording Interfaces
Waves Audio NLS Non-Linear Summing Plug-In
iZotope Mastering Essentials For Acoustica Mixcraft Pro Studio 6
Universal Audio Apollo Audio Interface
Auralex SonoLite Bass Traps At 2012 NAMM Show
Lynx Studio Technology Hilo Reference AD/DA Converter System
Expanded Sony MDR-7500 Series Professional Headphone Series
CAD Audio HA4 Headphone Amplifier, MH110 Studio Headphones
Auralex Portable & Stand-Mountable ProMAX Panels
Griffin Technology StudioConnect & MIDIConnect For iOS
Three New USB MIDI Keyboard Controllers From Alesis

At The Show…
“How To Get a Job In the Industry” Forum At NAMM 2012
NAMM 2012 Interactive Show Floor
Plan The 2012 NAMM Show Using Your Smartphone
NAMM 2012: Live Music In the Lobby Schedule
Comprehensive List Of NAMM 2012 Exhibitor Appearances & Events
NAMM 2012 Concerts & Performances
H.O.T. Zone Hands On Training Sessions At NAMM 2012
NAMM Hosts Congressional Briefing On Lacey Act
NSCA Education And Outreach Sessions At The 2012 NAMM Show
Educational Schedules For NAMM University At 2012 Show
Sennheiser Sound Academy Two-Day Live Production Workshop Prior To NAMM 2012
Meet The Winners Of The Third Annual Readers Choice Best Product Awards

Special Events
Audio-Technica Marks “50 Years of Passionate Listening” (Includes Video)
John Lennon Educational Tour Bus Marking 15th Anniversary At NAMM 2012
House Research Institute Offering Free Hearing Screenings At NAMM 2012
Lectrosonics Promising “Silent Booth” For NAMM 2012 Show
H.E.A.R. & NAMM Team Up To Prove Free Ear Plugs At NAMM 2012 Show

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A Look At Microphones Of The Past With Recording Legend Bruce Swedien

An excerpt from his book, "Make Mine Music," rife with need-to-know history and personal stories.

This excerpt is the first in a series from Bruce Swedien’s book Make Mine Music by Hal Leonard

Microphone Design Technology And Microphone Technique
Along with this development of a more live sound and hi-fi in the popular recorded music of the early 1950’s, a great deal of experimentation and improvement in microphone placement and technique was going on at the same time.

Much energy and effort were put into the development of innovative microphone design.

American microphone design technology and microphone technique were handed down from the broadcast industry to the recording industry, and were definitely ready for experimentation and improvement.

Many of the so-called unidirectional and bi-directional mikes of the time were actually omnidirectional in the low-frequency range of the audio spectrum.

Of course, this only accentuated the problem of too much reverb time in the low-frequency end of the spectrum in the day’s major recording studios.

To further intensify this low-end “coloration” of recorded music, the off-axis response of most of these older mikes caused very unpleasant and unmusical-sounding time and spectral coloration of the sound.

As microphone placement technique underwent radical and welcome experimentation and improvement in the early 1950’s, the introduction of exotic, new microphones, such as the Telefunken U 47 from Germany greatly improved the recorded sound of music.

In the fall of 1951, I was attending classes at the University of Minnesota. Walking from class to class on the campus, my schedule took me close to beautiful Northrup Auditorium.

A large concert hall with wonderful acoustic qualities, Northrup Auditorium was, at that time, the home concert stage for the Minneapolis Symphony (then under the baton of Antal Dorati).

As a kid, I had attended Minneapolis Symphony concerts almost every Thursday evening, with my mom and dad, at a time when Dimitri Metropolis conducted the orchestra.

The sight of that big, lovely concert hall reminded me of the fantastic sound of the orchestra in such wonderful acoustics that I had heard as a youngster.

Telefunken U 47
While at the University of Minnesota, I worked part-time at KUOM, the University radio station. Every Sunday afternoon, KUOM broadcast the Minneapolis Symphony Orchestra in concert (in mono, not stereo).

One day, in the KUOM studios I met a man by the name of Bob Fine, a recording engineer from New York who was in Minneapolis to record the Minneapolis Symphony for Mercury Records. He had in his hand a black box that resembled a miniature coffin.

This important-looking little black case was about 10” long, 2-1/2” wide, and about 2” high. Bob opened the case, and resting in it on a little bed of dark blue velvet was an absolutely gorgeous German microphone. Bells went off in my head!

I had never seen anything like it in my life before! It was the Telefunken U 47 microphone! I was most definitely in love!

I was, of course, very impressionable at the time, but I will never forget the sight of that exotic-looking microphone with its handsome chrome top and impressive machined metal-and-rubber shock-mount.

I couldn’t wait to hear how it sounded! Every time I look at my Telefunken U 47s now, my mind flashes back to that moment. Bob took the mike out of its case and showed it to me. He explained a bit about how it worked and how he was using it suspended 10’ above Mr. Dorati’s head.

That way, the microphone “heard” the orchestra in virtually the same balance as Mr. Dorati did.

This concept in microphone design, with its extremely wide and smooth frequency response, was almost like a miracle to me!

I had used condenser microphones before, but the Altec 21b condenser mike that we had at Jay Kershaw’s little basement studio didn’t sound anything like this!

Bob let us use the mike for a few days while he was there, to broadcast the Sunday symphony matinees on KUOM. The sound was absolutely fantastic!

I recall that there were also some television broadcasts of the Minneapolis Symphony Orchestra from Northrup Auditorium using that Telefunken microphone at about the same time. The use of this incredible mike was explained in detail on the TV program, and I remember watching and listening in rapt delight.

Here are a couple of interesting facts about one of my most cherished microphones, the Neumann U 47:

I later learned that the Germans had been experimenting with and had actually produced microphones of close to this fantastic quality 15 years earlier.

The Neumann U 47 was the first post-war mike produced by Georg Neumann GmbH in West Berlin. It was designed around a World War II military radio tube (that probably was in great supply at very low-cost) with a capsule design from 1929!

About 10,000 U 47s were made. It became the “benchmark” expensive (at $390) microphone in the early 1950’s, and engineers found out quickly that the sensitivity of the U 47 greatly enhanced the detail of their recordings.

The U 47 was a very popular vocal mike. There were many U 47s (and U 48s) used for the famous Beatles recordings, and George Martin, the Beatles’ producer, wrote that the U 47 is his favorite mike.

U 47s are pictured in abundance in the Beatles’ recording studio photos. Their aggressive sound makes them an excellent choice for lots of rock applications. Drums, guitars, amps, and brass instruments shine when sitting behind a U 47!

I bought my first pair of Telefunken U 47 mikes in 1954, from American Elite in New York, while I was still living in Minneapolis (I still have all the original paperwork).

They were a bit unusual in that they are the long-body, nickel-grille version. When those fantastic mikes arrived, it was a very big day for me. I was only 20 years old, and my two Telefunkens were the only U 47s in Minneapolis (I’m sure Bill Putnam had some Telefunken microphones in Chicago).

One of these precious mikes was stolen while I was working on Michael Jackson’s Thriller in 1982 (it’s one of his favorite vocal microphones). To this day, I use my remaining Telefunken U 47 on almost every project I am involved in. Isn’t it incredible that even today, this wonderful microphone is still often the first choice for miking many sound sources?

Now, let’s take a bit of a journey back in time with my Neumann U 47. It was in the early 1950’s that we began in earnest to attempt to improve the actual studio set-up of the musicians, singers, and microphones.

We abandoned many of the handed-down studio and microphone techniques of the past that had come from the radio broadcast industry. In the early 1950’s, microphone placement technique underwent radical and welcome experimentation and improvement.

At the same time, the introduction of exotic, new microphones, such as the U 47 greatly improved the sound of recorded music. The U 47 was probably the first microphone designed specifically for ultra-high-quality sound recording, with music recording as its primary intended use.

The Neumann Model M 49
A few years later, Telefunken introduced the Neumann model M 49 condenser microphone, another exotic model from Germany.

This is another of those wonderful microphones that is still in use today in the best world-class studios.

Designed in 1949, the M 49 was introduced to the buying public in 1950 as the answer to the question, “U 47?” It is a continuously variable multi-patterned, large (approx. 1”) dual-golddiaphragm microphone using the Telefunken ac-701 or ac-701k tube as its hub.

It had three different stand mounts, and it came in a variety of boxes. There were various models, including the M 49, M 49b, M 49c, M 249b, and M 249c.

The M 249b and M 249c were designed with an RF (radio frequency) suppression-type screw-on connector designed for the German broadcast industry. They usually utilized a “cassette system” power supply known as the N-52.

The M 49 is a superb vocal mike, but may be used for many other applications, from miking an electric guitar amp to recording French horns! Because of its adjustable polar patterns, it can be used in everything from omnidirectional mode for room miking to figure-8 for background vocals.

The Different Colors Of The Neumann Logo
Here are some small, but highly interesting facts. I love little historic details like the following:

There is a significance and meaning of the different colors of the Neumann logo on the various models of Neumann microphones.

Beginning with the Neumann “Bottle” microphone, the CMV 3, in 1928, Neumann microphones sported a logo with a black background.

This was used with all vacuum-tube-equipped microphones. For this reason, the microphones from the ’40s, ’50s, and ’60s feature the black logo, as well.

Beginning in 1966, the first transistorized (solid-state) microphones were offered by the Neumann company.

This was the 70 series for 12-volt A-B powering (also known as T-powering), with the models KM 73 through KM 76, plus the U 77 switchable-pattern model. For this series, the black logo was retained.

With the introduction of the microphones of the 80 FET series in the mid 1960’s, the 48-volt phantom power system was launched, and these microphones were identified by their purple Neumann logo.

The prime example of this series is the U 87. My personal favorite of this series is the U 47 FET. I have two U 47 FETs, very close in sequence numbers, that sound simply fabulous! I absolutely treasure these lovely mikes.

The currently used red Neumann logo signifies microphones with transformerless electronic circuits of the 100 series (e.g., the KM 140, TLM 170 r, RSM 191, TLM 193, or the KM 184) and TLM series.

Here’s Something To Think About:
“No sound system, no sound product, no acoustic environment can be designed by a calculator. Nor a computer, nor a cardboard slide rule, nor a Ouija board.

There are no step-by-step instructions a technician can follow. That’s like Isaac Newton going to the library and asking for a book on gravity.

Design work can be done by designers, each with his own hierarchy of priorities and criteria. His three most important tools are knowledge, experience, and good judgement.”

That quote is from Ted Uzzle, a Harvard-educated design consultant for motion picture facilities in Hollywood from 1973 to 1980 who joined Altec-Lansing in 1980, was made a fellow of the Audio Engineering Society in 1984, and became editor of S&VC (Sound & Video Contractor) magazine in 1992.

Innovative Placement Of The Musicians And Microphones
In early 1950, in an effort to improve the separation of musical instruments in music recording, the reverb time of modern studios was reduced.

A concerted effort was made by major-label and independent music recording studios alike to reduce the reverb time in the middle and lower frequencies.

It was also at this time that we began to use acoustical separation screens or isolation flats, or “gobos” – or whatever we wanted to call them.

These acoustical isolators were placed between instruments or whole sections of the orchestra to improve the definition and separation of the sound sources in a recording.

Using acoustical dividers in this manner made it possible for the microphone (or microphones) to be focused on a single musical instrument or group of instruments, and thus minimize the acoustic interference of other instruments playing at the same time.

In the 1930’s and 1940’s, the musicians and singers were arranged in the recording studio in an almost concert-like setup, and little or no effort was made to achieve clarity or apparent separation of sound sources in music. As a result, the sonic images of the musicians and singers in many old recordings is rather blurred and indistinct.

The year 1950 was the beginning of a very important decade for recorded music. With the release and incredible success of Les Paul and Mary Ford’s “How High The Moon” in 1951, it seemed as though a big section of the record-buying public was no longer interested in cold reality in popular music.

As the 1950’s came to a close, we in music recording found that reality in sonic image was not necessary, and perhaps not even desirable.

This innovation and improvement in technique actually began in the very early 1950’s, although when I began my work at Universal in Chicago in 1957, this renaissance in mike technique and studio setup was still very much in evidence. It was a wonderfully exciting time to be learning.

As a youngster in my early twenties, every minute of every day was full of new experiences in the studio. The big bands and musical artists that I worked with every day were very much in love with the recording process.

This is the first in a series of excerpts from Bruce Swedien’s book Make Mine Music by Hal Leonard

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Wednesday, January 25, 2012

New NAMM Board of Directors Elected During 2012 NAMM Show

NAMM’s voting members elected a new slate of nominees to the association’s board of directors at the Annual Meeting of Members during the 2012 NAMM Show in Anaheim.

The eight new directors joining the NAMM Board from 2012–2015 are:

Tom Bedell, Two Old Hippies, LLC
Tom Bedell and his wife, Molly, founded Two Old Hippies, LLC, a manufacturer and supplier of unique lifestyle brands featuring Breedlove and Bedell acoustic guitars and Peace, Love & Rock ‘n’ Roll apparel and gifts, with operations in Aspen, Colo.; Bend, Ore. and Nashville, Tenn. Twice inducted into the Iowa Rock ‘n’ Roll Hall of Fame, Tom holds a bachelor’s degree from Stanford University.

Keith Brawley, Gibson Guitar Corp.
Keith Brawley is president of Gibson Guitars for North America, a manufacturer of fretted instruments based in Nashville, Tenn. He studied at Moorpark College.

Tim Carroll, Avid Technology
Tim Carroll is vice president of worldwide audio programs for Avid Technology, Inc., a pro-audio manufacturer based in Burlington, Mass. He is a member of the SupportMusic Coalition. Tim studied at New England Conservatory, University of Georgia and Georgia State University.

Jonathan Haber, Alto Music
Jonathan Haber is president of Alto Music, a retailer based in Middletown, N.Y., with three full-line stores and one pro-audio location. He is a member of the Alliance of Independent Music Merchants advisory board. He holds a B.A. in history from Purchase College, SUNY.

Crystal Morris, Gator Cases
Crystal Morris is president and co-founder of Gator Cases, a manufacturer of cases, bags and accessories, based in Tampa, Fla. She is a member of the Young Presidents Organization, the National Association of School Music Dealers and the Percussive Arts Society. Crystal holds a B.A. in business from Stetson School of Business and Economics, and completed master studies at the University of South Florida.

Jeff Mozingo, Mozingo Music
Jeff Mozingo is president of Mozingo Music, a full-line retailer based in O’Fallon, Mo. He is a member of the Retail Print Music Dealers Association, the National Association of School Music Dealers, the Alliance of Independent Music Merchants, the National Association of Professional Band Instrument Repair Technicians and the Missouri Music Educators Association. Jeff holds a bachelor of music degree in percussion performance.

Jyotindra Parekh, Rice Music House
Jyotindra Parekh is president of Rice Music House, a retailer of pianos and keyboards, based in Columbia, S.C. He is a past board member and a current member of the Friends of the School of Music at the University of South Carolina, a Silver Sponsor of the Chamber Music Concert Series at the Columbia Museum of Art and a member of the Conductor’s Cabinet for the South Carolina Philharmonic. Jyotindra holds an MBA from the University of Detroit.

Menzie Pittman, Contemporary Music Center
Menzie Pittman is president and director of education at Contemporary Music Center, a two-store, full-line retailer based in Haymarket, Va. He is a member of the SupportMusic Coalition, the National Association for Music Education and the Fairfax Arts Coalition for Education.

NAMM

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Tuesday, January 24, 2012

L-Acoustics U.S. Sets Training Dates for KARA, KUDO & SOUNDVISION

L-Acoustics U.S. has announced its first two product training sessions for 2012.

The first three-day training is set for February 20 to 22 in Red Hook, NY and will specifically focus on the new KARA modular line source system and SOUNDVISION version 1.9.

The second session, hosted in Oxnard, CA exactly one month later from March 20 to 22, will cover the large-format KUDO line source system and SOUNDVISION.

“We’re particularly looking forward to our KARA and SOUNDVISION session in Red Hook as it marks our first official East Coast training,” says L-Acoustics head of U.S. touring support Scott Sugden. “We’ve had a lot of interest in a regional event like this from our eastern customer base and we’re very happy to now make it a reality for them.”

Primarily designed for technicians, mix engineers and sound designers referred by L-Acoustics Rental Network agents and clients, the first two days of each training will offer a blend of theoretical knowledge and field procedures focusing on operating and optimizing either KARA or KUDO in a safe and controlled environment.

A third day, which can be attended separately or in conjunction with the KARA/KUDO training, will be dedicated to covering the manufacturer’s SOUNDVISION 3D acoustical modeling software.

Upon completion of these seminars, attendees will receive a certificate of attendance.

The number of participants for both the Red Hook and Oxnard training sessions is limited to 12 people and priority will be given to L-Acoustics Rental Network agents and system owners.

For additional details on the training seminars and their related costs, click on the Support tab at www.l-acoustics.com or contact .(JavaScript must be enabled to view this email address).

L-Acoustics

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Monday, January 23, 2012

110th NAMM Show Reaches New Record Number Of Registrants

The National Association of Music Merchants (NAMM) today announced the final registration and exhibitor numbers for the 2012 NAMM Show, the largest and longest-running musical instruments and products trade show in the United States.

At show close, NAMM reported 95,709 registered attendees, a six percent increase from last year and representing a new record for the 110-year-old show. International registration also experienced a 15 percent increase from last year to 11,981.

The association previously reported strong exhibitor numbers, with 1,441 exhibitors at this year’s show, including 236 new exhibitors.

“Once again the NAMM Show served as the crossroads for musical instrument and live sound products manufacturers, retailers and their guests from all over the world,” states NAMM president and CEO Joe Lamond. “We are extremely grateful to all of the NAMM Members, music educators, artists, partners and media who made this 110th NAMM Show a resounding success for the industry and a great start to 2012.”

New and veteran exhibitors alike enjoyed increased foot traffic from quality retail buyers over the four-day show.

“We’d like to deeply thank NAMM for their incredible support during our first show as exhibitors.” says John R. Gibson, president and CEO, Wi Digital Systems. “Thanks to NAMM, we hit every stretch target, including major media exposure and signing up significant new accounts.”

“We were very pleased to see so much enthusiasm from our dealers at NAMM,” adds Courtland Gray, chief operating officer, Peavey Electronics Corporation. “Our new self-tuning Peavey AT-200 guitar, PVX powered speakers, Max Series bass amplifiers and more all made a very positive impression. We’re off to a great start for 2012.”

Themed “Make It Count,” this year’s NAMM Show focused on innovation in the form of apps and technology products designed to make playing music more accessible and easier than ever for consumers.

NAMM

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Monday, January 16, 2012

Revolabs Announces Online Training Courses For Wireless Systems

The new Revolabs Academy is a series of online training seminars designed to provide in-depth knowledge of the company’s family of wireless audio systems for unified communications.

“Over the past 18 months, we have conducted more than 25 day-long, on-site training seminars and the demand has far exceeded our expectations. Therefore, we’re moving the seminars online to extend this knowledge to an even wider audience and to offer more flexibility to our busy customers and partners,” says Eric Spata, director of global technical services for Revolabs. “Now, students can fit training into their schedules at their convenience, and we will be able to offer many more training sessions on a range of topics tailored to specific groups of users.”

Revolabs Academy training courses are open to all current Revolabs customers and end users as well as resellers, distributors, integrators, and consultants.

Courses will cover product-focused topics ranging from how to position and sell Revolabs systems, to how to troubleshoot and manage the installations.

Each course will be geared toward preparing students with the information they need to specify, install, and troubleshoot specific products in the Revolabs line, and gives them access to resources of which they might be unaware.

Most online courses may be started and finished at the student’s discretion, but some will be delivered in the form of scheduled webinars.

Upon completion of a certification, students will receive InfoComm International CTS Program Renewal Units (RUs) for industry certification renewal.

Go here for more information about Revolabs Academy, including upcoming courses and enrollment.

Revolabs

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John Lennon Educational Tour Bus Marking 15th Anniversary At NAMM 2012

The John Lennon Educational Tour Bus, a premier non-profit mobile recording studio and HD production facility, will kick off its 15th year of bringing music education to students nationwide with a special birthday party at the 2012 NAMM Show, to be held at the “Wanna Play?” Stage (Arena Plaza) on Friday, January 20, beginning at 6 pm.

The bus will be unveiling a new slate of equipment for the 2012 year, including Avid Pro Tools|HDX, and live streaming capabilities made possible by NewTek and TodoCast, that will allow the whole party to be seen live via www.lennonbus.org.

Hosted by principal sponsor Avid, along with Neutrik USA, DR Strings, Fishman, Ampeg and Mix magazine, the event will feature a performance by music legend Bootsy Collins joined by an array of special guests including Earth, Wind & Fire bassist Verdine White, fellow band mate from the Parliament-Funkadelic and Rock and Roll Hall of Fame inductee Bernie Worrell.

Collins has a rich history of supporting music and arts education through his own Bootsy Collins Foundation, and teamed up with the Lennon Bus in 2011 to produce an original song and music video with students from Austin, TX. Collins loved the track so much that he is now using the song to open all of his live shows. Check out the video here.

In addition to live music, the celebration will include remarks from John Lennon Educational Tour Bus co-founder and executive director Brian Rothschild, NAMM CEO Joe Lamond, Avid senior vice president of worldwide marketing Ron Greenberg and Neutrik USA president Pete Milbery.

“The Lennon Bus has celebrated many milestones at the NAMM Show, so it is very exciting to be kicking off our 15th year with this incredible line-up of performers and speakers, who all share the common goal of keeping music education alive,” says Rothschild.

“We are so proud to a principal sponsor of the John Lennon Educational Tour Bus and congratulate the organization on 15 years of making a real difference in music education,” adds Greenberg. “Avid, with the John Lennon Bus team, is proud to be able to bring to thousands of students the chance to work in a first class mobile audio and video production studio, and use the same state-of-the-art technology that professionals around the world use.”

John Lennon Educational Tour Bus

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Saturday, January 14, 2012

H.E.A.R. And NAMM Teaming Up To Provide Free Ear Plugs At NAMM 2012 Show

NAMM and H.E.A.R. are promoting hearing conservation by providing Mack’s Earplugs in bins around the NAMM 2012 trade show floor and lobby areas.

H.E.A.R. continues working together with the NAMM organization, as they have for many years, to help promote the importance of hearing health issues.

“We are noticing a real improvement in awareness through these efforts and I am very pleased to be able to contribute, in support of both the organizers and the attendees, for what we expect will be an outstanding NAMM show again this year,” reports Kathy Peck, co-founder and director of H.E.A.R.

In addition to free earplugs, visitors to the H.E.A.R. booth #2005 in the outer lobby outside of Hall D will be able to receive free ear impressions for custom fit items like musicians’ ear plugs and custom-fit personal monitors.

H.E.A.R. will also be showcasing its DVD, “Listen Smart: Safely Handling the Power of Sound,” the Cine Golden Eagle award-winning “rockmentary” produced by Dan Beck (HAMF) that features Ozzy Osbourne, Metallica and others designed to create awareness about noise-induced hearing loss (NIHL), and encourage safer practices when consuming high decibel sound.

Peck continues, “there truly is a wonderful change in the way musicians, sound engineers, music industry professionals and music students care for their hearing, but more needs to be done. It is our pleasure to continue our great relationship with NAMM to further help people protect themselves from hearing damage as well as to save whatever amount hearing they may have – even if any loss has already occurred.”

H.E.A.R.

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Friday, January 13, 2012

Properly Cleaning Your Microphones

Advice on cleaning and maintaining microphones to ensure their continued reliability

You’ve finally invested in a high-quality vocal microphone and your voice has never sounded better.

Unfortunately, the keyboard player in your band decides he wants to use your mic during his featured rap. You cringe as he practically eats the microphone.

You can barely watch as he encourages audience members to scream into the mic.

Afterwards he returns your mic, still operational but considerably wetter and unhygienic.

Microphones are subject to an inordinate amount of abuse, especially in live music. Grilles and foam windscreens can become saturated with saliva, clogged with lipstick, and will absorb the smell of cigarette smoke prevalent in most clubs.

Regular cleaning of your microphone will not only improve its performance, but is also good hygiene. This document provides several simple yet effective techniques for cleaning microphones.

Dynamic Microphones
The best way to clean a microphone is to remove the grille. Most vocal microphone grilles simply unscrew, e.g., SM58, BG3.1. If the grille doesn’t slide off easily, gently rock it back and forth while pulling it away from the cartridge. Do not pull sharply or with excessive force, since that could damage the cartridge or separate it from the microphone housing.

Once the grille is removed, it can be thoroughly cleaned without damaging the mic. Since most of the offensive material on the grille comes from the human body, plain water should be a sufficient cleanser. Adding a mild detergent (dishwashing liquid) to the water will act as a mild disinfectant and remove odors absorbed by the foam windscreen.

To remove lipstick and other material stuck in the grille, use a toothbrush with soft bristles. In some models, the foam windscreen can be removed from the grille, but this is usually not necessary since water will not damage the grille. Most Shure microphone grilles have a nickel finish that makes them resistant to rust, and replacing the foam windscreen can also be difficult and time-consuming.

The most important thing to remember is: let the grille dry completely before reattaching it to the microphone! Microphones don’t like water, and although dynamic mics can withstand small amounts of moisture, a soggy foam windscreen will introduce more than is acceptable.

Air drying is the best way to dry the grille, but a hair drier on a low-heat setting can be used. Care must be taken not to get too close to the grille as excessive heat can melt some windscreen material.

Cleaning must be done more carefully for microphones that do not have removable grilles, e.g., SM57, 545.

Using a damp toothbrush, hold the microphone upside down and very gently scrub the grille.

Holding the mic upside down will prevent excess moisture from leaking into the microphone cartridge.

This technique is also useful for cleaning the foam that covers the diaphragm inside an SM58.

Again, keep the mic upside down, and be very gentle.

In live situations with multiple acts, it may be desirable to clean the microphones between acts. Use a diluted solution of mouthwash (Listermint, Scope) with water. Using a toothbrush and holding the microphones upside down, scrub the grille of the microphone.

At the very least, this technique will make the microphones smell more pleasant to the performer. Also make certain the sound system is turned off before the cleaning begins!

Condenser Microphones
Due to the more delicate nature of condenser microphones, never use water or any other liquid for cleaning purposes. Even a small amount of moisture may damage a condenser element.

For microphones with removable grilles like the Beta 87 or BG5.1, the grille and foam windscreen may be washed as described above.

Again, the grille and windscreen must be completely dry before reattaching it to the microphone. To clean a microphone with a permanently attached grille like the SM81 or BG4.1, use a dry, soft bristle toothbrush and gently scrub the grille.

Keep the microphone upside down so that loosened particles fall away from it. Take care not to let stray bristles get caught in the grille. This technique also works well for lavaliers and miniature gooseneck mics.

For condenser microphones that will be subject to harsh conditions, such as vocals and theater applications, it is advisable to use a removable external foam windscreen.

This will protect the microphone from saliva and make-up, and can be removed and cleaned with soap and water after the performance. Remember, never get water near a condenser element!

(Provided by Shure Incorporated.)

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Thursday, January 12, 2012

NAMM Hosts Congressional Briefing On Lacey Act

On Thursday, January 12, the National Association of Music Merchants (NAMM) hosted a Congressional briefing in partnership with the U.S. House Manufacturing Caucus in support of the RELIEF Act (H.R. 3210), legislation that would fix the unintended negative consequences resulting from the 2008 amendments to the Lacey Act.

During the briefing, members of Reps. Don Manzullo’s (R-IL), Tim Ryan’s (D-OH) and Jim Cooper’s (DTN) staffs spoke in favor of NAMM’s public affairs efforts and encouraged caucus members to co-sponsor the Relief Act (HR 3210).

The bi-partisan House Manufacturing Caucus, co-chaired by Reps. Manzullo and Ryan, helps Congressional members and their staff to learn more about regulatory and legal issues facing America’s manufacturing sectors.

NAMM fully supports the RELIEF Act (H.R. 3210), introduced by Reps. Jim Cooper (D-TN), Marsha Blackburn (R-TN) and Mary Bono Mack (R-CA), to fix the 2008 amendments to the Lacey Act. This legislation would protect wood-products manufacturers, dealers and consumers from penalties for unknowingly violating the law.

NAMM has taken a lead urging congress to clarify the Lacey Act in a manner that would help ensure healthy forests, while protecting small businesses, craftsmen and musicians that love the American art of guitar making. For more information on the RELIEF Act, visit http://www.namm.org/publicaffairs.

The well-attended briefing helped congressional staff learn more about the regulatory challenges facing small businesses and artisans, among others, in the music products industry. The briefing also provided Mary Luehrsen, NAMM’s Director of Public Affairs and Government Relations, with an opportunity to promote congressional support for a legislative solution.

NAMM

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Keb Mo Named Keynote Speaker For 2012 AES Nashville Recording Workshop

The AES Nashville Section has announced that three-time GRAMMY-winning artist/songwriter/producer Keb Mo will be officially opening the 2012 Nashville Recording Workshop + Expo event on Friday, March 2, with a keynote address and interactive Q&A discussion with attendees.

Additionally, Mo and his engineer for both studio and live performance, John Schirmer, will be walking through the production of a complete song from start to finish in the final session of the first day of NRW+E 2012, giving their unique perspectives on both the technical and emotional experiences of making a recording and conveying the truest possible message on to the listener.

Having worked together on variety of musical projects, including production for artists on Keb Mo’s Yolabelle International label and musical scores for a multitude of television shows at his Stu Stu Studio in Nashville, this will afford a unique opportunity to gain insight to such a multi-faceted career and the creative process.

The Nashville Recording Workshop +Expo offers a compelling two-day recording workshop and gear exposition focused on getting the most from your personal studio recording environment.

AES Nashville, in conjunction with Audio Engineering Society, Inc. in New York is presenting this industry event on March 2 & 3, 2012 at the Rocketown event center at 601 4th Ave. South, near Nashville’s famed Music Row. Designed for recording musicians, songwriters laying down demos, and professional engineers working in a personal production space, the Nashville Recording Workshop +Expo will provide essential insight and information geared to boost your career and elevate creativity.

NRW+E presenters will include leading producers, engineers, acousticians, songwriters, and musicians sharing their professional techniques and knowledge in the areas of vocal and instrument miking, songwriters production of demos, arrangements and recording for better mixes, adding rhythm and spice with virtual tracks, collaboration across time and space, work environments that enhance creativity, practical acoustic and room treatment, and technical essentials.

Cosette Collier, chairman of the Nashville Section of AES. states, “We are thrilled to be able to offer the Nashville Recording Workshop + Expo once again this year.  For two days, NRW+E brings musicians, songwriters, small studio owners, audio production students and home recording enthusiasts together with professional recording engineers and music industry professionals, not for the typical ‘How I Do It’ kind of sessions, but instead, ‘How YOU Can Do It.’ Inspiration is part of the experience, but “take away” information is key.”

Nashville Recording Workshop +Expo featured events and demos will appear in a live, on-stage setting on a regular schedule throughout both days, while exhibitor booths and displays complete AES Nashville’s own convention-type setting, featuring manufacturers representing all aspects of professional audio gear and services.

“Early Bird” registration for AES members and members of participating professional songwriter, performance, musician and engineering organizations is $79, non-members is $99, student members is $39, and non-member students is $59. Early registration is open through February 3, 2012. For the full program listings, information on registering or to book an exhibition space visit: www.nashvillerecordingworkshop.com.

AES

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NAMM 2012: Live Music In the Lobby Schedule

The 2012 NAMM Show starts and ends each day with live music performances in the lobby of the Anaheim Convention Center!.

Here’s the schedule:

Thursday Morning
The Cabana Boys
Petiot Marching Band with the Get a Life Marching Band
1st Marines Division Band

Thursday Evening
The Tribute with the L.A. Scots and Doyle Dykes
Doyle Dykes and Friends

Friday Morning
The Wicked Tinkers

Friday Evening
The Living Legends Jam

Saturday Morning
Polka Floyd

Saturday Evening
Celebrity Jam featuring Band From TV and Celebrity Guests

Sunday Morning
National Show Choir Winners

Sunday Afternoon
The Mariachi Divas

NAMM 2012

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RE/P Files: Construction Of A Live Echo Chamber

From the archives of the late, great Recording Engineer/Producer (RE/P) magazine comes a wealth of knowledge about echo chambers which first appeared in the July / August 1979 issue.

A live echo chamber can be a considerable asset for any recording studio, that is providing that it is a good one.

That’s the problem — how do you construct a good echo chamber? When someone builds a chamber, they hope it will turn out great and pray it won’t turn out absolutely dreadful and good for nothing but storing echo plates.

The truth is there are a number of complex variables which will make each chamber unique.

These factors which effect the chamber include the type of wall construction and the selection of materials used on the inside surface.

Probably the most important consideration is the cubic volume and physical proportions of the chamber.

This leads to the first question to be asked before a chamber can be built. What space is available?

Space
Most times echo chambers occupy surplus space. The more space that is available to start with, the easier the construction job since the builder won’t have to deal with odd angles or cramped building conditions.

The size of the chamber can generally vary from 1,000 cubic feet to about 2,000 cubic feet of internal volume. 1,500 cubic feet seems to get excellent results within a workable space.

A small chamber won’t get optimum results and the largest chambers are a luxury since they occupy a space large enough to be usable for other purposes.

When determining if enough area is available, it is necessary to remember to allow for figuring the wall thicknesses.

There is also a need to consider a wide enough passageway around the structure for a hammer to be swung. If this isn’t planned for putting on the exterior sheeting is going to be a difficult proposition.

It is also suggested that the space be large enough to accommodate a chamber with a minimum interior dimension of 7 feet. A chamber with a side shorter than this will usually give unsatisfactory results.

The Floor Plan
Once it has been decided that there is enough space, the next step is to design a floor plan (Figure 1). When laying out the sides of the room none of the walls should be parallel or even near to parallel. The ceiling should not be parallel to the floor. This is very important if the room is to have maximum random reflections and a smooth decay. It’s at this stage that a bit of math should be introduced (1).

T = Const X M/α S

where:
T = Reverberation time
V = Total volume of the room in cubic units
S = The total combined surface area of all sides in square units
α = The average absorption coefficient Constant:
.049 if measurements are in feet.
.161 if measurements are metric.

The American National Standards Institute (in S-l. 1-1960) defines reverberation time of a chamber as the time it takes for the mean square sound pressure level to decrease to 60 dB after a steady state signal has ceased (2). Generally this level is referenced to 500 Hz although some information relates the level to 1 kHz.

The following equation for figuring decay time was developed by Wallace Clement Sabin (1900). Since his time there have been a number of alternate equations developed but the original equation continues to be the most popular. This is due partly to the simplicity of the computation and the similarity of the resulting data.

Sabin determined that the reverberation time was related to the volume of a room, its surface area and the total amount of absorption.

As the formula would indicate, the time is directly proportional to the volume and inversely proportional to the surface area of the room. With this being the case, the longest echo will be obtained when the required volume is achieved with a minimum of interior surface area.

Trying to achieve more diffusion in the chamber by building accordion type splays will have the effect of cutting down the delay time because the total surface area will have been increased.

Another point to be remembered when figuring out the length of the sides is that none of the dimensions between any two opposing walls should be the same or a multiple or fraction of any other two opposing walls.

There are a number of ratios which serve as guides when figuring acceptable proportions, including the Golden Section; (5^1/2 + 1): 2 :( 5^1/2 - 1).

This relationship was proposed by the Greeks and divides a line in such a manner so that the smaller dimension is to the greater as the greater is to the whole. There are four or five other ratios which have been proposed and accepted to varying degrees, (3) but the one most often used is Sabin’s 2:3:5 relationship. (Figure 2) (3)

Wall Angles
The angles used for the intersecting corners should not be severely acute. In practice, the simplest way to arrive at the wall angles is to build the sides so that two of the joining sides meet at right angles.

Their opposing walls are constructed similarly, but without permanently nailing down the floor plate. Once these walls have been framed, the entire unit can be angled inward. For the average chamber moving one end of each of these two walls in by a foot or so should be sufficient.

Rigidity And Isolation
Two things which are important in making a good live echo chamber are maximum interior wall rigidity, and the total isolation of the chamber from its surroundings.

The more rigid the wall is, the less energy dissipated when a sound wave hits it, hence the surface is more reflective. The isolation is important since it’s essential that the rooms broadband ambience be very low.

Echo chamber wall systems which achieve these goals can be constructed from a variety of materials. There are a few chambers that have been built with walls, floors and ceilings of poured concrete. Such a design if properly executed will get very good results, but will be expensive to build, very permanent and extremely heavy. It will be there forever, providing you haven’t underestimated the strength of your sub- floor.

The second most popular approach is concrete block walls. They are easier to build, and a bit easier to tear down, but once again you have the weight problem.

The most popular and cheapest type of construction is a wood frame design made of 2” x 4” and 2” x 6"s. It is the easiest to build with hand tools and more importantly is relatively light compared to concrete and block.

Walls
In recording studio construction it is very popular to use 2” x 4” staggered stud construction since the results achieve a better transmission loss than a conventional wall. (Figure 3) A staggered wall uses two rows of studs 8” apart (2” x 4” alternating 16” centers) on 6” top and bottom plates. Every other stud is flush to the opposite edge of the plates. In this way the wall sheeting of the two sides is only connected at the top and bottom plate.

A standard stud wall uses a 2 x 4 plate. The sheet rock covering both sides is connected through each of the common studs. The transmission loss between these two types of construction with insulation is STC 36 dB for the standard wall and STC 49 dB for a staggered wall.4

The staggered wall would be the preferable wall design if transmission loss were the only consideration, however, rigidity is a more important factor in the design of the inside shell, hence standard construction is preferred. (Figure 4)

The reason for this is that staggered construction does not allow enough space for cross bracing. The interior shell should have a cross brace splitting the span of every stud, joist, and beam. There should be no unbraced span longer than eight feet.

The preferred layout is to use a staggered exterior wall, and a standard interior one. These two walls should not be coupled in any way and hopefully will not only be decoupled from each other but from the rest of the building.

Floating Walls and Floors
A very important part of the de-coupling of an echo chamber is isolating it from the building it sits in. What sort of isolation is needed will depend on the specific situation and the funds available.

The drawings shown use Celotex for de-coupling. As can be seen, the outer shell is de-coupled from the floor of the building, while the echo chamber has a completely floated floor.

If the location requires extreme de-coupling then it might be necessary to construct the outer shell on its own completely floated floor. It is also likely that something other than than Celotex will be needed.

Machine rubber is a good alternative to Celotex. It seems to work acceptably when used in a quiet environment but it does seem to compress a great deal and might break down with time. A thickness of or more is necessary.

In an extreme isolation situation involving low frequency vibration more severe measures will be necessary. The worst case may need a floated concrete floor on spring isolators, but once again you have considerable weight and expense.

The best material which has been found for most situations are Fiberglas decoupling blocks. As shown, they are two inch cubes, covered with latex (to keep the moisture out) and are specially designed for floating floors. They can be used for both concrete and timber designs.

When they are used with concrete, a sheet of plywood is laid over them and a border runs around the plywood to create a pouring form. Be sure all cracks in the form are sealed so that none of the concrete will seep and re-couple the floating floor to the structural one.

When the blocks are used with wood construction, they should be set under three or four 2” x 6” headers. The timbers form the base for the echo chambers floor joists. Isolators should be placed about a foot or so apart along the entire length of the headers.

The only problem with the block spacers is the gap it leaves between the floating floor and the structural floor. The solution is to fill the space with Fiberglas and run the sheetrock down to %” away from the floor caulk.

These blocks are available from a number of suppliers. The blocks can also be used to isolate ceilings from walls. For this application the blocks seem to work best if they are split in two.

A chamber built on a concrete ground floor can be further de-coupled by using a concrete saw to cut a slot around the perimeter of the chamber. This helps quite a lot in isolating the rest of the building from the chamber. The newly formed slit can be stuffed with Fiberglas but a hard sealer should be avoided since it will slowly harden and compress and re-couple the slabs.

Insulation, Sheetrocking and Sealing
All the walls should be liberally stuffed with foil backed Fiberglas insulation (3%” #R-11). Note: when working with the glass, be sure to always wear gloves, goggles, a mask, and clothes that won’t allow the glass to touch your skin.

Both sides of each wall are covered with sheet rock. Two layers of y2” sheet rock is specified for the interior wall but two layers of 5/8” will work just as well or better. When two layers are used one should overlap the other so that none of the seams coincide.

All seams should be taped and sealed so the room will be airtight. In addition to standard seam Hydroseal which is a black gummy adhesive is highly recommended.

It is normally used as a roofing sealer and will stick to anything. It should be used liberally at every structural intersection of the sheeting or the stud construction. You end up using gallons of this stuff and practically glue the building together.

The purpose of the Hydroseal is to close every crack or seam. The smallest crack should not be ignored. If you have a 1/32” crack along the floor, the actual total area of that hole is considerable.

A final note on Hydroseal. It is suggested that trowels are unnecessary for the application. Wood shims made from construction debris works a lot better. These are good for only about one or two applications. It is almost impossible to clean Hydroseal off anything, including the applicator.

The Chamber Surface and Its Application
After the walls have been built and the last inside layer of sheet rock has been taped and sealed, the chamber is ready to have its reflective surface treatment applied. The reflective walls of the echo chamber can be made from a number of different materials.

The key to how good a particular material is for this application depends on how rigid it becomes after installation and what its absorption coefficient is. Referring back to the earlier formula, the length of the echo is inversely proportional to this coefficient.

The absorption coefficient of any material is defined as “the ratio of sound energy absorbed by a given material to that which arrives at the surface from the source.” (5)

Hence, a porous surface will have a much higher number than a reflective one. This figure will not only be different for each material but vary widely depending on the frequency. Figure 5 shows an absortion coefficient chart of materials versus frequency. As can be seen, plaster has a remarkably low number and is relatively flat. The plaster which Scott uses is Keen Cement (absorption coefficient of .015). He says, “when it is properly applied, it is as smooth as a baby’s bottom.”

Before plastering the surface, the sheet rock has to be prepared so that it will hold the plaster. This is done by nailing on the actual buttonboard.

The actual plastering involves the application of two different layers. The bottom one is a brown coat layer and is put on as a preparation for the top coat of Keen cement. It is strongly suggested that the actual plastering be done by a very good professional.

The mixing of the two cements is nothing more than following the directions on their respective bags. One of the most important things to remember about the plastering process is the amount of time required for proper curing.

As often happens the chamber is complete after the final coat of plaster is applied and there is a desire to use it right away. If the chamber doors are closed prematurely, ventilation will stop as will the drying of the walls. How long it takes for a wall to properly dry changes with the temperature, ventilation, and humidity of the environment, and can vary from a few days to a few weeks.

The longer you can continue to ventilate a new chamber, the better. Scott suggests hooking up a dehumidifier in the room during the drying. He added, “you’ll be surprised how much water comes out of those walls.” This is a crucial part of getting the best end results.

“I have been in chambers that were built years ago that have walls that have never completely cured.” Needless to say such a room has a poor reverberation.

Some chambers sound bad only because the plaster coat was improperly applied. In such cases all that might be necessary is a re- plastering. It is also likely that an additional layer of buttonboard will be necessary so that the new plaster will have a firm base.

Connections And Doors
The chamber should have an IN and OUT opening so that the speaker and microphone lines can be kept separate. The pipe used should be flexible and have an I.D. of 3/4”.

Increase the diameter if there is a need for more than two or three lines per pipe. The smaller it is, however, the less possibility there is for any leakage. Plastic hose works well because it is flexible, has gentle curves and there are no ridges inside for wires to hang-up on.

Make the hole through which the hose is run as small as possible since you want to maintain the integrity of the wall system as much as possible. Once the hose has been installed, any gap between the hose and the wall should be completely caulked with Hydroseal.

A door is obviously needed somewhere in the chamber. Be sure the access to the door and the passageway leading to it is large enough to get a good sized speaker in and out of the chamber.

The two doors used should be of solid construction, not hollow. They are mounted on completely separate frames and jambs to coincide with the de-coupled inner and outer walls. (Figure 6) Machine rubber should be used between the two frames where they almost touch (%” to between the walls.

Rubber should also be used completely around the jambs of the two doors. When they close the rubber should compress and make a tight seal. Since these doors are generally used infrequently, an elaborate closing is unnecessary.

Additional Construction Notes
A light should be installed somewhere inside the room. The switch for it can go anywhere convenient including right on the fixture. Be sure that de-coupling practices are maintained while running the AC conduit and mounting the fixture.

All the walls are built with studs on 16” centers. When laying out the studs, be sure to take into consideration that the drywall is 8’ or 12’ high and 4’ wide and the centers of every third stud needs to line up with the edges of the drywall. #16 nails are used for all end nailing and #8 for toe nailing.

Drywall nails are used on the first layer of drywall, but because of the added thickness #8 nails are used on the second layer. The buttonboard should be nailed on with #8 nails.

Be sure to estimate lumber lengths thoughtfully, to limit the amount of scrap.

However what is left should be used for blocking. The greater the waste, the more the chamber (and for that matter any type of construction) will cost.

Speaker(s) and Microphone(s)
Changing the speakers and microphones or altering their placement will change the sound heard in the control room. Deciding what type of speaker sounds best or what microphone should be used becomes a matter of taste.

This is equally true as to where they are placed in the room.

Providing there was adequate space to start with and care was taken with the design, construction, and isolation considerations, it is probable that the chamber will end up sounding very good.

With a little bit of luck, it might turn out to be the sort of chamber that gains a reputation for itself as well as the studio that has it.

References:
1 - Sound Recording Practices, J. Borwick; “The Acoustics,” by Alex Burd, Oxford Press, page 27.
2 - Acoustic Design and Noise Control, M. Rettinger, Chemical Publishing, page 25.
3 - Acoustic Design and Noise Control, M. Rettinger, Chemical Publishing, page 87.
4 - Handbook of Multi-Channel Recording, F. Alton Everest, Tab Publications, page 261.
5 - The Audio Encyclopedia, H. Tremaine, Sams Publications, page 44.

Scott Putnam has been extensively involved in studio construction, having designed and built a number of echo chambers including two for Kaye- Smith in Seattle, and a pair for the Record Plant. As a builder he has collaborated on various projects with a number of acoustic consultants and architects including Jack Edwards, George Augspurger, and Scott’s Father, Bill Putnam.

Downloadable Media
Original Article (pdf)

Editor’s Note: This is a series of articles from Recording Engineer/Producer (RE/P) magazine, which began publishing in 1970 under the direction of Publisher/Editor Martin Gallay. After a great run, RE/P ceased publishing in the early 1990s, yet its content is still much revered in the professional audio community. RE/P also published the first issues of Live Sound International magazine as a quarterly supplement, beginning in the late 1980s, and LSI has grown to a monthly publication that continues to thrive to this day.

Our sincere thanks to Mark Gander of JBL Professional for his considerable support on this archive project.

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