Up The Chain
After you’ve established the level of all the passbands, with delay applied to those bands that need it, the system should now be sounding pretty good without a single bit of EQ on it.
If it doesn’t sound right, revisit the bandpass gains and work with them until it starts to gel.
Using the bandpass gains can be just like using a wide-band EQ. There are lows, low-mids, high-mids, and highs (if it’s a 4-way system).
The bandpass gains can tailor the response of the system before you reach for the system EQ. And less EQ keeps the phase response of the system more intact.
Just be conscious of causing too much overlap in the crossover region, especially with subs. The crossover point may need to be lowered every time the gain is raised.
I typically don’t touch the main EQ until the band starts sound check. If the system has a few rough spots, I leave them be and start going through the band’s inputs using channel EQ where needed. If I keep cutting a particular frequency on every channel, I’ll reach for it on the main EQ instead.
While the band is playing their “sound check song,” I then use the main EQ to tailor the system response based on what the band sounds like, and the microphones being used for that particular show. Because the band and mics are variables that can alter day to day, it makes sense to EQ only after I hear that band play over that system with those mics.
Less Is More
If a parametric EQ is available for the mains, I reach for it first because it offers so much more control than a graphic. Offending frequencies can be cut or boosted without affecting other parts of the system. With a graphic EQ, pick only the band that really needs the cut or boost – don’t grab four or five faders all next to each other and bring them all down in a pretty little curve! (And remember that graphics can behave very differently from one another.)
The detrimental effects of EQ add up with every fader that’s touched. It’s much better to grab one frequency and cut it -10 dB than to grab four frequencies and cut each -2 dB. With a parametric EQ, one wide and smooth cut can be made with one wide and smooth change in the phase response, versus five narrow cuts with five narrow changes in the phase response. See the difference?
Even better, if it seems like several adjacent frequencies need to be adjusted at once, go back and change the gain on that bandpass. It will have limited effect on the phase response, but a powerful effect on the frequency balance.
At virtually any point in this process, if I think it sounds good enough, I stop. Knowing when to stop is probably one of the hardest things to learn in live sound production. I’ve ruined a good thing more than once by continually tweaking until the last note of the last song. Don’t be that person.
And lastly, when you invest in the tools and education to learn advanced measurement techniques, you’re on the path to be better at what you do. Happy mixing!
Tim Weaver is the owner of Weaver Imaging, an audio, lighting, and projection provider based in College Station, TX. He has been a professional sound engineer for 18 years, working across all genres.