Corporate Audio Sound

Jan 1, 2012 9:00 AM, By Chris Thomson



Education Guide

Mix is gearing up to present its longstanding annual Audio Education Guide in its November 2014 issue. Want to have your school listed in the directory, or do you need to update your current directory listing? Add an image, program description, or a logo to your listing! Get your school in the Mix Education Guide 2014.

Proper lav placement

Proper lav placement

The microphone used for this corporate event (and most A/V events in general) was a wireless lavalier: a Shure UR4S. The obvious advantage of a wireless lav over a podium mic is mobility; the disadvantage is poor gain-before-feedback. The small-cap condenser element on these UR4S mics has the same cardioid pattern element used in my favorite podium mic, the Shure mx418. The crucial difference is where the mics face the mouth.

Two problems with a lav on clothing are low-end chest resonance and chin blockage. Placing the lav mic element about seven inches below the person’s head is good practice. If it is too far down, the mic doesn’t pick up as much of the voice, causing more feedback issues. If pinned too high, the mic picks up even less high end. Generally, the console preamp has to be pushed harder, and the high end (8 to 20 kHz) needs to be boosted. The extra gain will require more EQ adjustments.

The equalization techniques required for a corporate event are quite different than the techniques used doing sound for a band. A presenter at a corporate event is just talking and sometimes a timid person will speak at a very low volume. This, compounded with the feedback-generating position of lav mics, requires a careful “ringing out of the room.” It is often taught at audio schools that only four to five feedback frequencies should be moderately notched out of your 31-band or parametric EQ. This is a rule that I strongly believe in but rarely see followed by beginner sound engineers. Pulling too many frequencies (ones that are not actually feeding back) will just bring down the room’s overall sound level and lead to descriptions like muddy, tin-like, fake, thin, etc.

Although the compromised speaker placement at the CoStar event posed a feedback problem, I was able to get plenty of gain using careful and spare EQ adjustments. During the day, Brandon acted as a test speaker onstage. Soon I had rung out the feedback frequencies on my rack’s 31-band EQs. Next, I worked on the mic input channel strips of the Midas Venice. Boosting the strip’s 12kHz knob brought my assistant’s voice “to life” with the high-end “air” that is the part of the human voice. Often there are multiple mics on at once, and the variety of presenters will need different adjustments. A good sound person should be able to dial in EQ adjustments within seconds of a speaker talking.

Wireless microphone programming can be problematic in today’s RF-bombarded airspace. In general, most wireless mic transmitters will not send signal through more than two walls, so it is doubtful a mic kit being used in a hotel across the street is going to cause you any trouble. But all kits being used in your building should be set on different frequencies and monitored closely. Most mic manufacturers have preset groups of frequencies that do not interfere with each other, but sometimes you are forced to use multiple group settings because of a lack of open RF channels on one group. In this case, you should turn on all the mics and test them to uncover any intermodulation problems. RF problems can be greatly reduced with proper preparation; however, it is a good idea to have a wired mic or extra wireless handheld available onstage in case hits occur.

Typical EQ settings on the Midas

Typical EQ settings on the Midas

Compressor technology comes in handy when amplifying the speaking voice. A person speaking into a podium mic should be standing with their head about a foot away. In reality, this is sometimes not the case. If they are too far back, a well-rung-out system will still pick up the person’s voice. If they do the opposite and get their mouths too close, the microphone can be overloaded and create loud, boomy “plosive” sounds. Cutting some of the low end on the channel strip will help, but the main tool to fight this problem is a compressor. Compressors have many uses when mixing a live band, but this is the main use when amplifying sound in the corporate setting.

As I mentioned before, a lavalier mic input should be set to pick up strong level (good signal-to-noise ratio) without clipping (proper headroom). This method of setting a strong level should continue down the signal flow chain, through your preamp, EQ processing gear and all the way out to your speakers. Having a preamp set low will cause problems as boosting a weak signal down the chain can raise the noise floor. Another problem with a weak preamp level is you may not be able to see the channel’s LEDs light up. These lights come in very handy when a group of people is onstage and you are riding the faders. Adding mics onstage will increasingly reduce the gain you have available. Every time you double the number of mics, you lose 3 dB of gain-before-feedback. For example, two open mics will lower your volume 3 dB and eight mics will lower it 9 dB. This is quite a bit of volume loss; even the best sound person will be riding faders in this situation.

Sound engineers working in a corporate setting will face difficult situations. Meeting planners expect excellent results regardless of the room’s shape, stage positioning, table setup and screen locations. And in many ways, with just a voice out front, clean audio is even more crucial. If you have a room of 40 venture capitalists and they are talking big deals, every word counts.

Think back to what you learned in school, then apply it in the real world. The basics do matter: proper speaker positioning, effective lavalier microphone placement, human voice specific EQ techniques, correct wireless RF programming, podium microphone compression and correct gain structure. Understanding these issues is necessary for success in the world of corporate sound.

Acceptable Use Policy
blog comments powered by Disqus

Mix Books

Modern Recording and Mixing

This 2-DVD set will show you how the best in the music industry set up a studio to make world-class records. Regardless of what gear you are using, the information you'll find here will allow you to take advantage of decades of expert knowledge. Order now $39.95

Mastering Cubase 4

Electronic Musician magazine and Thomson Course Technology PTR have joined forces again to create the second volume in their Personal Studio Series, Mastering Steinberg's Cubase(tm). Edited and produced by the staff of Electronic Musician, this special issue is not only a must-read for users of Cubase(tm) software, but it also delivers essential information for anyone recording/producing music in a personal-studio. Order now $12.95



Delivered straight to your inbox every other week, MixLine takes you straight into the studio, with new product announcements, industry news, upcoming events, recent recording/post projects and much more. Click here to read the latest edition; sign up here.

MixLine Live

Delivered straight to your inbox every other week, MixLine Live takes you on the road with today's hottest tours, new sound reinforcement professional products, recent installs, industry news and much more. Click here to read the latest edition; sign up here.

[an error occurred while processing this directive]

The Wire, a virtual press conference offering postings of the latest gear and music news, direct from the source. Visit the The Wire for the latest press postings.