Compressors, feedback, and live sound
James85
Posts: 63
I have three 266XLs that I have used for vocal compression in live sound. I have read the dbx Compression 101 and a few other basic sources. I have experienced the difference in sound a compressor makes when someone disconnected them on the vocal section at my church. Personally, I have been experimenting with compression on screaming/growling hardcore vocalists, and also snare and kick. These DIY shows are often a circus and I don't get to really experiment too much or the music is so darn loud you can't hear the diff anyway.
To the point. I had a visiting engineer/drummer ask to tweak my settings since he knew what the band should sound like, he was a recording guy (he is), etc, etc. After he fooled with my compressor settings he kept getting feedback from the snare mic when there were no snare hits. He noted he was a studio guy and asked if it was ok to to hit the "red levels" on the outputs of everything. I sensed something was amiss! The Heil snare mic was giving us deeper feedback, not a squeel.
More recently I had a similar "feedback when there was no vocals" problem. I am sure it was my compressor settings because I yanked the inserts and the problem was solved. Came back when I plugged them back in. Again I got the high-pitch squeal.
I am thinking it may be my threshold settings. My settings, off the top of my head, are pretty conservative. 2:1 ratio, fairly fast attack and release on vocals, make-up level at 4-6.
Can someone explain what creates the feedback with improper compressor settings. Where am I going wrong?
FYI-my system EQ, through the DR, was flat except for a few cuts. A&H GL2400 mixer, xti 4000s on MRX525 tops and LA400 subs, with proper grain set-up. No whacky channel EQs.
Thanks guys!
Jim Layton
To the point. I had a visiting engineer/drummer ask to tweak my settings since he knew what the band should sound like, he was a recording guy (he is), etc, etc. After he fooled with my compressor settings he kept getting feedback from the snare mic when there were no snare hits. He noted he was a studio guy and asked if it was ok to to hit the "red levels" on the outputs of everything. I sensed something was amiss! The Heil snare mic was giving us deeper feedback, not a squeel.
More recently I had a similar "feedback when there was no vocals" problem. I am sure it was my compressor settings because I yanked the inserts and the problem was solved. Came back when I plugged them back in. Again I got the high-pitch squeal.
I am thinking it may be my threshold settings. My settings, off the top of my head, are pretty conservative. 2:1 ratio, fairly fast attack and release on vocals, make-up level at 4-6.
Can someone explain what creates the feedback with improper compressor settings. Where am I going wrong?
FYI-my system EQ, through the DR, was flat except for a few cuts. A&H GL2400 mixer, xti 4000s on MRX525 tops and LA400 subs, with proper grain set-up. No whacky channel EQs.
Thanks guys!
Jim Layton
0
Comments
In Live sound I try to use VERY LITTLE gain on miced sound...Direct sound like bass.. higher compression ratio's and even makeup gain are possible. Compression in the monitor chain is really a no no unless you have major chops in the livesound business...
You mentioned DR.. in this case I "assume" Driverack DRPA? DRPA+?
Are you using the DR in the proscribed manner? Are you Auto EQing? What method do you use? Please be as specific as you can. Are you Auto Eqing the monitors?
Inquiring minds and all...
G