What each frequency sounds like
Short answer: the lows are weight and body, the low mids are where mud and boxiness build up, the middle honks, the upper mids bite and bring things forward, and the top is sizzle and air. Mix Chops splits the range into nine bands, one octave apart, from 63 Hz to 16 kHz. Play each one below, boosted or cut, on pink noise and on a full mix, and learn a name for it.
Start on pink noise: it plays every frequency at once, so you hear the band itself. Then switch to the full mix, where a band only changes the instruments that have something there. On the full mix, 16 kHz changes very little: this track, like the others in Mix Chops, has little energy up there. A cut is harder to hear than a boost, because you’re listening for something that’s gone. Use headphones or decent speakers: laptop and phone speakers can’t play the low bands.
The nine bands
63 Hz: sub weight
You feel this more than you hear it. Kick weight, 808 pressure. Small speakers can’t play it, so you keep adding more. That’s how mixes end up bass-heavy.
125 Hz: body and warmth
The note of the bass, the body of the kick, the chest of a vocal. Too little and it sounds thin. Too much and everything gets thick and slow.
250 Hz: the mud zone
Almost every instrument piles energy in here. If your mix sounds woolly or congested, look here first. I cut this band more than any other.
500 Hz: boxiness
The cardboard box band. Untreated rooms build up here, so drums tracked in them come out hollow and knocky. A narrow cut usually sorts it.
1 kHz: honk
Nasal, like a voice down a phone line. Vocals, guitars and horns all honk here when it’s overcooked.
2 kHz: bite and attack
Pick attack, snare crack, the part of a vocal that cuts through the band. Your ears are very sensitive from here up, so small moves sound big.
4 kHz: presence and edge
Consonants, stick on skin, the hard front of every note. A little brings things forward. Too much is what people usually mean by harsh.
8 kHz: sizzle
Cymbals, breath and S sounds. De-essers work around here for a reason.
16 kHz: air
Openness above everything else. A gentle shelf up here opens a mix up. Go too far and you’re just turning up hiss.
A problem that sits between two of these? The names still help: they tell you which way to listen. For mud in the low mids, How to fix a muddy mix walks through finding it and cutting it. Where each instrument sits across the bands is on the EQ frequency chart on danmurtagh.com.
Hz, kHz and octaves
Hz (hertz) counts vibrations a second, so 63 Hz is 63 a second. kHz is a thousand of them: 1 kHz is 1,000 Hz, and 16 kHz is 16,000. Each band here is an octave above the last, twice the frequency. Ears hear octaves as even steps, which is why EQ graphs are spaced that way. Spaced in octaves, 1 kHz sits in the middle of the nine bands, with four below it and four above.
Doubling the frequency is also what moves a note up an octave, so the nine bands sit close to the same note, a B. As pure tones, 250 Hz is close to the B below middle C, 500 Hz the B above it, and 1 kHz the B an octave higher. 8 kHz and 16 kHz are far above the top note of a piano, about 4.2 kHz. In a mix you don’t hear a band as a note, though. You hear it as a colour across everything playing there.
Below 63 Hz, and above 16 kHz
People hear from about 20 Hz to about 20 kHz. Below 63 Hz is the deepest sub: the open E string of a bass guitar is about 41 Hz, and under that is mostly rumble you feel. Plenty of speakers and headphones barely play it. Above 16 kHz is the last of the air, and hearing up there fades with age, so many adults hear little of it.
Telling neighbours apart
Much of the work is telling a band from the ones either side of it: 125 from 250 Hz, 2 from 4 kHz. Play two neighbours in the demo one after the other, then put the difference into words. How to train your ears for EQ has a way to tell apart every neighbouring pair.
Questions
What does 40 Hz sound like?
A deep rumble you feel as much as hear. It’s about the lowest note of a four-string bass, whose open E is about 41 Hz. Many speakers and headphones barely play it, so it’s easy to have too much of it without knowing.
What does 500 Hz sound like?
As a pure tone, close to the B above middle C. In a mix, 500 Hz is boxiness: too much and things sound hollow and wooden, like they’re in a cardboard box.
What does 1 kHz sound like?
As a pure tone, a fairly high note, close to the B nearly two octaves above middle C. In a mix, 1 kHz is honk: too much and vocals, guitars and horns sound nasal.
What frequency range can humans hear?
About 20 Hz to 20 kHz. The top of that range fades with age.
Why can’t I hear 63 Hz on my laptop?
Laptop and phone speakers are too small to play the lowest bands, so 63 and 125 Hz turn into guesswork. Use headphones or decent speakers.
What’s the difference between Hz and kHz?
A kHz is a thousand Hz: 1 kHz is 1,000 Hz. Both count vibrations a second. Low notes are tens or hundreds of Hz; the top of the range is in kHz.
Name the band by ear.
Identify plays a boost or a cut on one of these nine bands, and you name it. It starts on pink noise with three bands to choose from, and ends on full mixes. Sweep hides a boost and has you find it, against the clock.
Train it in IdentifyThen: Sweep · Free, in your browser, no account