EQ Explained: How to Use an Equalizer When Mixing Music

An equalizer is a volume knob that only touches part of the sound. Turn down the area where a vocal sounds muddy, turn up the area where it sounds clear, leave everything else alone. That's the whole idea. Learning how to use an equalizer is the single biggest jump in mix quality most people ever make, and you can learn it free in a browser: SoundCraft, our online DAW, has an 8-band parametric EQ called the Eagleizer on every channel. This post teaches EQ for real, using that panel as the classroom.

What an equalizer actually does

Every sound you record is a stack of frequencies, measured in hertz. Low numbers are bass, high numbers are treble, and everything from a kick drum to a voice spreads across a range of them. An EQ lets you grab one slice of that range (a "band") and raise or lower just that slice, measured in decibels. A band has three settings: the frequency it's centered on, the gain (how far up or down), and Q, which sets how wide the slice is. Low Q is a broad, gentle scoop. High Q is a surgical pinpoint.

In the Eagleizer, all of this lives on one graph. Click anywhere on it and a band appears right where you clicked, as a Bell filter with a Q of 1.0. Drag the point left or right to change frequency, up or down to change gain, and roll the mouse wheel over it to tighten or widen the Q. Double-click a point to delete it. You get up to eight bands per channel, and each one can be any of six filter shapes: low cut, low shelf, bell, notch, high shelf, high cut.

Quick translation of those shapes. A bell boosts or dips around a center point, and it's what you'll use most. A low cut (also called a high-pass) removes everything below its frequency, which is how you clean rumble out of a vocal. Shelves raise or lower everything past a point, gently, like a treble knob on a stereo. A notch cuts one narrow frequency to nothing, for hums and whistles. One small detail I like: when a band is set to a cut or notch shape, the panel's Gain knob grays out, because those shapes don't use gain at all.

Learn the frequency map first

EQ moves only make sense once you know roughly where things live. These numbers aren't exact science, but they're close enough to act on:

• 20 to 60 Hz, sub bass. You feel it more than hear it. Most vocals and guitars have nothing useful down here, just rumble.
• 60 to 250 Hz, bass. The weight of a kick drum and a bass guitar, and the warmth of a voice.
• 250 to 500 Hz, low mids. The mud zone. Too much energy here makes a mix sound like it's under a blanket.
• 500 Hz to 2 kHz, mids. Body and honk. Boxy-sounding recordings usually have a bump in here.
• 2 to 6 kHz, presence. Clarity and the edge of consonants. This is where a vocal cuts through.
• 8 kHz and up, air. Sheen and sparkle, and also where harshness and hiss live.

How to use an equalizer in SoundCraft

1. Create a free account. The editors cost nothing; paid plans only add storage and server compute.
2. Open SoundCraft and drop in a song or a vocal take (a temporary session is fine).
3. Click the clip so its channel is focused.
4. Open the ☰ effects rack and click the Eagleizer EQ tile. It's first in the list.
5. Click the graph to add bands, drag them into place, wheel for Q.

Here's a starting curve for a typical home-recorded vocal, and the reasoning behind each move:

• A low cut at 90 Hz. A voice has no melody down there, but mic thumps and room rumble do. Cutting them frees headroom you didn't know you had.
• A 3 to 4 dB bell cut around 300 Hz with the Q tightened to about 2. This is the classic fix for a muddy or boomy vocal. Sweep it between 200 and 400 Hz to find the exact spot on your voice.
• A gentle 2.5 dB bell boost at 3 kHz, left at the default Q of 1 so it stays wide. This pushes the vocal forward without making it loud.

Notice the sizes. Nothing here moves more than 4 dB. Beginner EQ curves look like mountain ranges; experienced ones look almost flat. If a track needs 10 dB of anything, the problem is usually the recording or the arrangement, and the fix is a retake, not a bigger boost. If you're starting from scratch, our guide to recording vocals in the browser covers getting a clean take in the first place, which makes every EQ decision easier.

Cut first, boost second

The most common beginner instinct is to boost what you want more of. It works, but it costs you: boosts eat headroom, and a dozen small boosts across channels add up to a loud, smeared mix. Cutting what you want less of gets you to the same balance cleaner. Want a brighter vocal? Before you boost 3 kHz, try cutting 300 Hz. The vocal gets clearer and the fader stays where it was.

Three fixes I use constantly:

• Muddy vocal: bell cut, 2 to 4 dB, somewhere in the 200 to 400 Hz zone. Almost every untreated-room recording needs this.
• Harsh cymbals or a spitty vocal: high shelf pulling everything above 8 kHz down a couple of dB. Softer than chasing each harsh peak individually.
• Kick and bass fighting: give each its own pocket. Cut the bass a few dB around 60 Hz where the kick thumps, and cut the kick around 100 to 150 Hz where the bass note sits. Each cut is invisible on its own; together the low end opens up.

Find problem frequencies with a sweep

You'll read "cut the harshness" everywhere, but nobody tells you how to find it. The trick is a narrow boost used as a search tool. Add a band, push it up around 8 dB, and tighten the Q to 3 or 4 so it's a sharp spike. Hit play, then drag the point slowly across the graph. Most of the range will just sound louder. Then you'll hit a spot that makes you flinch, where the boost turns genuinely ugly. That's your problem frequency. Drag the band's gain from boost down into a cut at that exact spot, or note the number and delete the band (the ✓ on its band button removes it too).

EQ in context, not in solo

Solo is a liar. A vocal EQ'd to sound gorgeous by itself often disappears the moment the beat comes back, because the beat was masking different frequencies than the ones you polished. Make your EQ decisions with the whole mix playing. Solo briefly to identify a problem, sure, but judge the fix in context. This is also why a thin-sounding solo'd guitar is often correct: it's leaving room for everything else.

Related: EQ each channel for its role, not for fullness. If every track is EQ'd to sound huge, they all fight for the same space and the mix turns to soup. In SoundCraft you also get a second EQ on the master bus, next to the master volume fader. It ships flat and I'd keep it mostly flat; a half-dB shelf to brighten a finished mix is reasonable, and it does carry through to the exported file.

Once the EQ is sitting right, the usual next stops are compression and tuning. We've covered how to Auto-Tune a vocal in the browser, and if you're new to SoundCraft itself, the free online DAW walkthrough tours the whole editor.

The honest summary: learn the frequency map, prefer small cuts over big boosts, sweep to find problems instead of guessing, and judge everything with the full mix playing. The Eagleizer gives you the same tools as any paid parametric EQ, and it runs on every channel of a free browser DAW, so the only thing left between you and decent EQ instincts is repetition.