I don't equalize for a specific type of program so much as for the room. Most of my work is punk rock concerts, but the same idea works for any live sound gig.
The first time a band has to
sound-check with me, they think I'm out of my mind. I don't wait for
feedback to happen and try to fix it. Instead, I intentionally cause
feedback... during the
sound check. After the show, they usually thank me - they could actually hear what they wanted from the monitors.
What I'm doing is finding the frequencies that the room itself reinforces, then notching those frequencies out with the graphic EQ.
I start with the EQ set
flat, both for mains and for monitors, and set a good but fairly quiet main mix...
channel faders set to 0dB, submasters set to 0dB, main faders set to about -15 dB,
monitor master knobs (my board has uncalibrated rotary knobs for monitors) just above 50%. I use the input
gain knobs to set an initial
level for each
channel (faders are for tweaking relative levels to sweeten the basic mix as necessary), then use the channel-strip
monitor sends (and requests from the musicians), to
build good, but somewhat quiet,
monitor mixes.
Then I'll start increasing the overall
level on one of the
monitor master knobs until it just barely starts to feed back. I'll make a best guess as to the frequency of the
feedback and
pull down the
fader for that frequency on the graphic for that
monitor mix. If that kills the
feedback, I guessed right. If not, I put the
fader back up and try the ones on each side of it, one at a time. If necessary, I keep spreading out from my original guess until I hit the one that stops the
feedback.
Then I go back to the
gain and push it up a little farther, until it starts feeding back at another frequency. Again I'll make a best guess, with the advantage that I know whether it's higher or lower than the one I just got done with. I repeat the procedure until I've got four or five frequencies notched out.
Then I go back to the first frequency and push it up, slowly, until it just barely starts to feed back, then pull it back down the tiniest fraction, until the
feedback stops. Repeat for each frequency I notched out originally, then back the
monitor master down by about 10%.
Then repeat the whole procedure for the next
monitor mix (I can run up to four, but usually only do two... and that's often better than most of the bands I work with get from anybody else).
Finally I do the same with the main mix. By causing
feedback during the
sound check, I've found the frequencies where
feedback is likely to occur and cut them down in the mix, both for the mains and the monitors. The result is that I can push the
system, especially the monitors, a lot harder without causing
feedback during the show. It works well enough I've actually had the occasional musician ask me to turn the monitors down - something you almost never hear a musician say.
While it may be time consuming at first, with practice you get to the
point where your first guess at the
feedback frequency is usually right and it goes pretty quickly. And not only is it louder, it sounds better, because you've compensated for the room accoustics.
John