EQ is pretty simple, right? Crank a knob, hear the sound’s tone change?
Not quite. Just when you think you know everything there is to know about EQ, something new comes up. Here are a few advanced EQ techniques that you might not be using to full potential.
1. Mid/side EQ
Any true stereo sound might be able to be enhanced with mid/side EQ. It basically turns your stereo EQ into a frequency-specific stereo width adjustment tool.
You’ll get the most natural results by only processing the side channel. You can boost the top to increase clarity and dimension. You can narrow the mids to provide focus and punch. You can high-pass the bass to easily collapse the bass to mono without touching the mids and highs.
2. Spectral matching EQ
This one’s usually a multi-step process. First get the EQ to “listen” to some reference audio (such as another track or commercial mixdown), then get the EQ to “listen” to the audio you want to process.
Finally, the EQ can then either match the two (so that the processed audio sounds similar to the reference audio), or it can compliment the two (so that the processed audio sounds very different to the reference audio).
Matching EQ can be useful whenever you want one track to sound like another. Obviously, this might be useful in mastering, but it can also come in handy when working with samples from a variety of different sources.
Compliment EQ can be useful if you want to make sure two tracks do not interfere with each other.
3. Dynamic EQ
This is an interesting one. It allows the gain of each EQ band to change dynamically with the level of the audio. It can work a lot like a multi-band compressor, except that the envelope follower controls the gain of an EQ band instead of a frequency range. This allows you to get much more surgical and specific with how the audio is processed.
The most common use of dynamic EQ is de-essing vocals, where the high frequencies are turned down when there’s too much sibilance. It’s also useful for other situations where a recorded track needs to be cleaned up in a specific way, but static EQ or broadband compression are too blunt for the job. Things like low frequency bumps or thuds, or the occasional odd midrange resonance are sometimes good opportunities to use dynamic EQ.