Understanding EQ

EQ — equalization — is step two, after gain and before compression. At its core it’s simple: raising or lowering specific frequency bands (boosting or cutting bass, mids, or highs) to change the sound of a source. Tip: wear headphones for this one so you can actually hear the frequencies being found and removed.

Three reasons to EQ

1. Make it sound natural — a vocal should sound like a vocal: not muddy and dark, not bright and harsh.
2. Fix a problem — hide or minimize a weird ring, buzz, or resonance.
3. Make it fit the mix — an instrument can sound great alone but need shaping so it sits well with everything else.

(Remember: fix it at the source first. EQ is for what’s left.)

The tools

We use a parametric EQ (the flat line = doing nothing). Each band has three controls:

• Gain — how much you boost or cut.
• Frequency — where on the spectrum you’re working.
• Q (bandwidth) — how wide or narrow the affected range is.

Other shapes and filters:

• Bell — boosts/cuts around a center frequency (the classic curve).
• Shelf (usually on the high/low bands) — lifts or drops everything above or below a point.
• High-pass filter — cuts the lows, passes the highs.
• Low-pass filter — cuts the highs, passes the lows (used less often).

Start with the high-pass filter

If EQ confuses you, start here. A high-pass cuts out low frequencies a channel doesn’t need — frequencies that just add mud. A vocalist generates almost nothing below ~100 Hz (higher for a female voice), so an open mic down there is only picking up room noise and rumble.

Rule of thumb: high-pass everything by default. A 100 Hz high-pass on every vocal out of the gate already helps. High-pass the hi-hat and anything with no real low end. The exceptions are your bass instruments — kick and bass guitar — let those shine down low. Direct sources (keys, DI guitars) matter less, but open mics are where it really counts because they hear everything in the room.

Cut problems, don’t boost to mask them

Brian’s philosophy: cut first.

• Acoustic too bassy? Don’t add highs — cut the problem lows.
• Guitar too harsh and bright? Don’t add lows — cut the problem highs.

Boosting to cover a problem just piles up energy; cutting the offending frequency actually solves it. Beyond that, a little gentle tone shaping to taste is fine.

The trick: boost, sweep, cut

Here’s how to hunt down an ugly frequency:

1. Boost a band hard (~12 dB).
2. Sweep the frequency knob around until the ugly thing — boxy, muddy, tinny, zingy, harsh — jumps out loudest.
3. Cut there instead, then use Q to broaden or narrow it.

“Ugly” is whatever sounds unnatural to you — boxy, muddy/unclear, or cheap-and-tinny. Acoustic guitars (piezo pickups) often have a harsh mid-range zing worth cutting. Use broad strokes for natural-sounding tone; save sharp, narrow cuts for specific rings and resonances.

Think about the whole spectrum

There are only so many frequencies to go around. The danger zone is the ~200–300 Hz low-mid buildup, where directional mics’ proximity effect stacks up and instruments collide into mud. A keyboard might sound perfect solo, but a gentle shelf pulling down its low-mids makes it sit cleaner with the band. Always mix the channel with the whole puzzle in mind, not just in isolation.

EQ with your ears, not your eyes. Just because it looks good on the graph doesn’t mean it sounds good.

EQ in passes: give it a first pass, listen in the full mix, then add or back off. Check the cheat sheet for solid starting curves (kick, bass, acoustic, drums), then dial them in by ear.

Application

• High-pass every vocal at ~100 Hz this week and listen to how much mud disappears.
• Practice boost-sweep-cut on one instrument until you can find its ugliest frequency in under a minute.
• Pull up the full band and listen for buildup around 200–300 Hz — what’s colliding there?