Kick and bass occupy the same two octaves, so they are not two parts that need balancing — they are one part played by two devices. Everything below is about making them agree: on pitch, in time, and in phase. Two of the labs measure the result rather than describing it.
A kick drum is three events stacked in the first half second: a broadband transient, a pitch that falls fast, and a sustained fundamental. Genres differ almost entirely in the ratio between them.
The pitch envelope is the whole personality. Fall fast from high (150–320 Hz) and you get punch and attack — tech house, hard techno. Fall slowly from low (110–130 Hz) and you get weight and roundness — dub techno, deep house. The end pitch is the note the kick actually plays, and it is the number that has to agree with your bass.
Every kick below is synthesised live from these six parameters. Load a genre preset, then move one slider and watch both the waveform and the spectrum change. The readout tells you what note the kick is currently playing.
All eight presets are already tuned to A minor — the note is in the preset name. That is not how kicks normally arrive; a sample pack kick is whatever pitch someone happened to record. Section 03 is about what happens when it isn't.
Reading the display: the orange trace is one kick hit in the time domain (0–600 ms). The bars behind it are the spectrum from 20 Hz to 1 kHz on a log scale — the tall bar on the left is your fundamental, and the spread to the right is click and drive harmonics. If there is nothing on the left, you have a click, not a kick.
Rumble is not a kick parameter in most people's heads, but it is the defining sound of contemporary hypnotic techno: a long reverb tail on the kick, filtered low, feeding back into the space between hits. Push the rumble slider up on the Hypnotic preset and the kick stops being an event and becomes a continuous bed. That bed is the bassline in a lot of records — which is why so many rumble techno tracks have no separate bass part at all.
Your kick plays a note whether you chose one or not. If that note is a semitone away from your bass root, the two beat against each other several times a second and the low end sounds unstable and cheap — and no amount of EQ fixes it, because the problem is pitch, not level.
The bass is fixed on A. Move the kick around the chromatic scale and listen — not for "wrong notes" but for a slow wobble in the low end. A and E lock solid. C and G sit fine. A♯ and G♯ produce an audible beating that gets faster the further out of tune you go. That beating is the two fundamentals interfering, and its rate is literally the difference between the two frequencies in Hz.
Ten bass sounds that carry ten different genres, each played over a house kick so you hear it in context. All in A minor at the transport tempo. The recipe on each card is what to build in Operator, Wavetable or Analog to get there.
Sidechain compression is usually taught as a mixing fix — stop the bass and kick from clashing. It is much more useful to think of it as a rhythm generator: the release time sets a pulse that the whole track breathes at, and that pulse is a note value.
The white curve is the gain applied to the bass over one bar; the red marks are the kicks. Watch what happens when release passes a note boundary: at a 1/8 release the bass recovers exactly as the offbeat arrives and the groove locks; at 1/4 it never fully recovers and the track turns into a continuous pump; below 1/16 you get a click-like duck that reads as tightness rather than movement.
The one that costs people whole tracks. When your kick and your sub occupy the same frequency at the same moment, their phase relationship decides whether they add up or subtract. Nothing on the meters warns you — the mix just sounds quiet and weak, and turning the bass up makes it worse.
Both sounds are 55 Hz. At 0° they reinforce and the peak reads high. Sweep to 180° and the summed peak drops — often 6 to 10 dB — even though you added nothing and removed nothing. Your ears hear it as the kick losing its weight. This is exactly what happens in a real project when a sub note lands underneath a kick with the wrong polarity or a few milliseconds of offset.
Once pitch, timing and phase agree, the remaining work is deciding which sound owns which band. There is only room for one thing at a time down there.
The frequency table is the one to keep open. Scale tones of A minor are marked in red — those are the notes your kick is allowed to be.
| Note | Oct 0 | Oct 1 | Oct 2 | In A min |
|---|
| Release | ms @ 126 BPM | Feel |
|---|
| Band | What lives there |
|---|---|
| 20–35 Hz | Felt, not heard. Rumble and room. Often worth removing entirely. |
| 35–60 Hz | The weight. Sub fundamentals, kick fundamental. |
| 60–100 Hz | The punch. Where kick and bass fight hardest. |
| 100–200 Hz | Body and warmth. Too much here is the definition of muddy. |
| 200–500 Hz | Where a sub becomes audible on small speakers. Saturate here. |
| 2–6 kHz | The kick's click. What cuts through on a club system. |
| Genre | Kick | Bass | Sidechain | Who owns the sub |
|---|---|---|---|---|
| Classic house | 909, 55–60 Hz, ~400 ms | Offbeat saw, short gate | Moderate, 1/8 release | Shared, kick slightly |
| Deep house | Soft, 50 Hz, long | Sine sub + organ layer | Gentle, long release | Bass |
| Disco house | 707-ish, 65 Hz, short | Plucky 16th funk line | Light or none | Bass |
| Tech house | Tight punch, 58 Hz, 250 ms | FM growl, offbeat | Hard, short release | Kick |
| Hypnotic techno | Long + rumble tail | Often none — the rumble is the bass | Heavy on everything else | Kick |
| Hard techno | Distorted, 62 Hz, clicky | Distorted saw or hoover | Extreme | Kick |
| UK garage | Short, sharp, 60 Hz | Sub + organ stab | Moderate, swung | Bass |
| Acid | 909, dry | 303 line, resonant, gliding | Light | Kick |
Symptom first, because that is how you actually encounter these.
The order of operations. Pitch, then timing, then phase, then level, then EQ. Almost everyone works that list backwards, starting with EQ on a kick and bass that are in different keys and cancelling each other — which is why the EQ never fixes it.
Everything here is synthesised live in the browser. The synths are approximations built to demonstrate relationships, not to replace your plugins. All examples in A minor.