If I could only give one tip for working EQ it would be to cut first, boost if you have to. There are a few good reasons I say this, but first I want to make sure we all know what I’m talking about.
Cut first, boost if you have to
Last week we said that EQ is a volume control for a specific frequency. It lets you add or subtract gain at a specific frequency to [hopefully] balance the sound of a source. Boosting turns up a particular frequency, while cutting turns it down. So, if the goal is to make everything heard clearly, why shouldn’t we just turn up the frequencies we want to hear? I’ll give you two reasons: one technical and one artistic.
The technical reason is that, when it comes to EQ, boosts aren’t as clean as cuts. Boosting frequencies soon results in a signal that’s much louder than it was when you started. Louder signals aren’t a bad thing – making things louder is an essential function of mixing audio – but EQ isn’t the cleanest tool for the job. Boosting at the EQ add noise and takes away headroom, both of which are bad things. Cutting does neither. So if you need to add gain, do it the right way: with the gain knob (there’s a whole post on it here).
But it’s not all science. One of the big picture goals of mixing is to accurately represent what’s happening on stage. Cutting what doesn’t belong, rather than boosting what you want to hear, tends to leave the source more intact and natural sounding.
Let’s say you’re working with a muddy vocal. You could boost presence by 6dB at 5kHz and it would sound clearer, for sure. But, since our ears tend to focus on what’s loudest, we would tune into that relatively narrow 5kHz range. If, instead of boosting the presence, you decided to cut 6 dB at 400Hz, you would clean up the muddiness at the source. Now our ears would hear an even spread of all the frequencies we started with, except some 400Hz where we made a cut. This is why boosting results in a narrow sound and cutting results in a fuller sound. When we boost, our ears tune into the narrow boosted band. When we cut instead, our ears can pick up on everything that’s left, which is usually a more balanced, natural sound.
Of course, I’m not saying you should never boost. I boost EQ bands fairly frequently, but almost always after I’ve made cuts. Going back to our muddy vocal, I might still add a presence boost to the voice. But, after cleaning up the problem frequencies, that presence boost might only be 1-2dB instead of 6dB.
It’s important to listen to how it sounds, not how you want it to sound. This simple reminder can be a major course correction. As artists, we want to be creative. We want to make something. But as audio mixers we can’t create sound, we can only work with what we’re given. Heavy boosting is sometimes an unconscious attempt to create sounds that aren’t there. Do you need to create a sound that’s not there? Grab a guitar! Or better yet, talk to to the musicians and song leader and work together to get a great sound at the source.
[If the audio geek inside you is asking, “hey Jared, doesn’t EQ add phase shift too?” My answer is, “of course it does! That’s how EQ works!” If you re-phrase your question and ask “okay, smart-aleck, doesn’t EQ add unwanted phase shift, or phase smear?” My new answer is “I’m not sure!” If you have a strong opinion on the subject, leave a comment or come find me and we’ll have a rousing debate!]