Some of my YouTube.com/c/deberney subscribers have been asking how to tame and prevent feed-back while recording or playing with a PA system.
Feed-back is one of those things that when starting out can ruin a performance or recording. Especially when you have no idea what is causing it or how to fix it.
There are many different ways to tame feed-back and it helps to know as many as you can humanly absorb as one or two remedies are never enough to tame the beast.
I remember the first time Ken, Dick and I played at the nursing home. OMG! We had so much feedback. Having played this nursing home, solo, for the past year, I never dreamed of the problems I would face playing the same room with two other band mates.
We played in a dining room, tiled floors, bare walls the ideal situation for sound problems.
Dick had a little amplifier. I had an acoustic guitar, Ken had electric and acoustic guitars, we all had microphones. I made the mistake of setting everything up as I did for my solo performances. PA speakers to left and right behind me, facing towards the audience. Which turned out to be a big mistake as I spent the better part of our performance, trying to control the feedback. I tried to control it with volumes on the mixer rather than moving the mic / speaker placement or adjusting EQ.
With that performance I was determined to not have that experience ever again and after watching numerous Youtube videos on “preventing feedback” and reading everything I could find, the real cause of feed back slowly started to take shape in my mind. I learned that feed back is caused by sound vibrations from speakers that are picked up and amplified by the microphone. I found that different mics had different patterns and knowing the pickup patterns of the microphone would help in placing musicians, microphones, speakers in the proper positions to prevent the unwanted feed-back. I learned that placement of instruments, mics, amplifiers and speakers are essential in taming the feed-back beast.
I learned that setting up in a new environment always presents it’s own challenges. I start volumes (for each channel) turned off. Set volumes and EQ one channel at a time for each instrument and microphone. Your mixer should have a “sweet spot” for the main gain. A safe place to start is 1:00 and adjust according to your setup. If you do experience problems with feedback, move the microphones around until you find the quiet spot. Do this one at a time before trying them all on at the same time. It will be easier to tweak. You may have to do this with amplifiers and acoustic guitars as well. You don’t want any of the speakers or mics to be in line with one another. You want your PA speakers to have a clean path out towards the audience.
Hopefully this gets you started and helps you tame the FEED-BACK BEAST.