This doesn't fit in the normal gear discussion, so I dropped it here since it's live sound.
We're having a bit of a feedback problem in the choir loft - we sing into a large space and have 3-4 condensers covering the choir in addition to a couple of SM57/58 for soloists. The choir director has to ride the faders a fair amount during masses to catch feedback and silence the group between songs, especially when the pastor is booming (a pair of overhead monitors project the main floor's microphone mix at us - debatable as to whether that's a good idea, but I'm not in charge of the sound system).
It's just the low "honk" kind of feedback you get from a basic loop, not wicked shrieking.
I was thinking of snagging one of these to set under the 14-track Mackie, which I think, if set correctly, will let us kill the feedback and some of the between-song chatter without ruining the dynamic of the choir:
Behringer MULTIGATE PRO XR4400 Quad Expander/Gate: Shop Pro Audio & Other Musical Instruments | Musician's Friend
A) Anyone with similar sound experience know if that will do the trick, and
B) WTF are the "parametric sidechain filters," and will those help fine-tune the gate response or are they useless in this application?
I think you'd be better off with a feedback eliminator instead of a gate, but a gate would do it.
The parametric side chain allows you to select which frequencies are used to determine if there's signal or not. Not really helpful in this situation.