Sound system gonna bring me back up, yeah...one thing that I can depend on

February 8, 2008 1:03 PM

AudioEngineerFilter: I'm now in charge of a medium-sized (50 people) auditorium and the sound output system is okay, but the wireless mic system is limited to two mics (a handheld and a lavalier), and it needs upgraded...and quick!

The room is a large round table which will have the guests/participants sitting around. The requirement is to capture everyone's voice with a wireless mic and broadcast it right back out to the room. There are speakers everywhere.

We have one lavalier mic that transmits instantaneously and causes godawful feedback if you're anywhere near any of the speakers, and one handheld with a slight delay (100ms?) that has virtually no feedback unless you're on top of the speaker. I was thinking we could buy some kind of omnidirectional wireless microphones that sit quietly in strategic locations around the round table, picking up whatever anyone is saying and transmitting it over to the mixer, feeding it back into the system - enough for everyone to hear, but not enough to feed back into the mic. I'm also inclined to introduce a delay inline so there would be less feedback (amateur that I am). But I don't know who to buy from and what to get!

Any suggestions? Can you recommend a delay and a set of wireless omnidirectional mics (and a receiver)? I have a nominal budget of $1000, but it can be more if it needs to. Thanks!

posted by ostranenie to media & arts (5 comments total)

I think what you're looking for are called boundary microphones.

I can't recommend a specific brand, but that term should help focus your searching a little bit.
posted by davey_darling at 1:18 PM on February 8, 2008

A few questions:

- Are you speakers in the ceiling all over the room, or are they in just a few places?
- Does it have to be wireless?
- Do the people around the table need help hearing what others around the table are saying?
posted by jjb at 6:30 PM on February 8, 2008

Sorry, forgot to add:

Look for a 'squelch' potentiometer on the lav, either on the bodypack or on the reciever, you might be able to cut some of the feedback that way.
posted by jjb at 6:31 PM on February 8, 2008

@Jjb:
- There are seven speakers in the ceiling located around the round table.
- I'd rather it be wireless because I have the money and I definitely want it to look good (high profile meeting, lots of suits and ties), and I want to be able to position it wherever without trailing a wire.
- Ultimately I'd like to make everyone at a given mic sound like they are "everywhere." Is this possible with boundary mics?

I'll check the lav receiver for a squelch pot, I didn't see one on the pack. Thanks!
posted by ostranenie at 9:25 AM on February 10, 2008

Boundary microphones will probably help quite a bit, and they're designed for use on conference tables and the like.

Adjusting your speaker placement will also help a lot, possibly more than anything you'll do in terms of signal processing. Even the best microphones will give you feedback if you have them too close to the speakers. Depending on how many speakers you have, you might want to think of using a mixer that allows individual monitor-style mixes to each group, so you can control which mic inputs end up at which speakers. This will give you a lot of additional feedback-suppression control.

For the delay, what you'll probably want to get is something called an "Effects Processor." It'll have controls for reverb, delay, comp/limiter/gate, possibly bandpass filters, and a lot of crap you'll never use unless you want to sound like a cheesy karaoke hall. Here's one example at Sweetwater. They are relatively inexpensive. (I'm partial to Lexicon units but I really don't think it'll matter too much for what you're talking about.)
posted by Kadin2048 at 1:40 PM on February 10, 2008