Each one runs in your browser, and each one rests on something I measured. About half the time the measurement was the surprise.
102 shipped70 make noise52 larger buildsall playable on a phone
The pump of house is a compressor on the pad keyed from the kick, and the release knob is the sound. Measured off the pad's own level: a kick every 469 ms pushes it down 16 dB, and with a 150 ms release it's more than 3 dB down for 82% of every beat, back in 378 ms. At 50 ms that's 51% and 220 ms, a dent. At 400 ms it never gets back, a quieter pad. The worklet compressor rendered offline agrees. Twelfth of twelve.
The M1 organ bass under half of house is a Hammond in software: drawbars that hold, a percussion harmonic that comes in 17 dB above them and decays in 150 ms, and a click of 31 dB of high frequency in the first five milliseconds. All three read off the sound, the percussion to within 10 ms of its setting. It fires only on a note played alone, so a legato phrase gets it once, and that's the feel.
A 909 snare is two tones at 180 and 330 Hz and a burst of highpassed noise, and the tones decay faster than the noise, so every hit stops being a drum and becomes a hiss at some moment. Measured off the sound, that moment is 84 ms at half snappy, 203 at a quarter, and never arrives at full because the noise leads from the first millisecond. The two decays predict 91 and 202. Play it, or let it play the two and four.
A clap is four bursts of noise 10 ms apart and a tail. A drum machine gates one noise source, so every burst is fresh. A sampler layers one burst on itself, so every burst is the same noise, and a sound that repeats every 10 ms wears a comb of peaks every 100 Hz. Measured: the copied clap repeats exactly and its comb is 23 dB deep, the fresh one never comes closer than a third of the way and has no comb at all. Same envelope, same ear, different spectrum.
A 909 hat is six square waves at 205, 254, 370, 304, 523 and 800 Hz, frequencies picked to share no period. Measured by sliding the sound against itself, the closest it ever comes to repeating is 49% different. Snap the same six onto a 50 Hz grid and it repeats exactly every 20 ms, and a tone appears where the metal was. Play it, tune it, or let it play house hats.
A 303 slide is a lag on the pitch in semitones, so it takes the same time whatever the interval. Measured off the sound, a semitone and an octave both get 63% of the way in 59.8 ms and 95% in 180 ms, and an octave covers twelve times the ground in that time rather than taking twelve times as long. The accent opens the filter 1.4 octaves and adds 3.5 dB, and leaving the level out makes an accented note measure quieter than a plain one.
Pulse width does not filter, it deletes. A rectangle of width d has harmonic h at four over pi h times the sine of pi h d, so harmonic h is exactly silent whenever d is a multiple of one over h. Measured on a real rectangle against that formula, every harmonic lands within a thousandth of a dB, and sweeping the width takes each harmonic to silence exactly floor(h/2) times between nothing and a half. Play it, or let it play rave stabs.
Seven sawtooths spread across a detune, and the seven lines around every harmonic get h times further apart as you go up. Measured on A3 at 40 cents, the fundamental swells 53 dB and the beating dies at harmonic 36, where the voices are 183 Hz apart, against 43 predicted from where the clusters touch. At 80 cents it dies at 18 and at 10 cents it never does. That's why a supersaw beats at the bottom and hisses at the top.
Two sines, one modulating the other, and the spectrum is a Bessel function. Measured against the arithmetic at every ratio and index the page offers, the worst sideband is 0.18 dB out. At an index of 2.405 the first zero of J0 takes the note out of its own sound, 80 dB down while the sound stays loud, and a decaying index passes through that null 62 ms into every note, predicted at 61. At a ratio of 1 or 2 the folded sidebands land back on the note and the null only half happens.
A wobble is a saw through a resonant lowpass swept by a tempo locked LFO, and it doesn't sweep, it steps. The filter peak can only land on a harmonic of the note, so on a 55 Hz saw it climbs a staircase of 32 harmonics from the third to the 45th, a fourth wide at the bottom and 0.39 of a semitone at the top, going round 4.6 times a second on an eighth note at 140. Sharp resonance lifts each step 18 dB, soft lifts it 6. Play it, or let it play a bassline.
The reese is two saws a few cents apart, and every harmonic beats at its own multiple of the detune. At 15 cents on A1 the fundamentals drift round each other every 2.09 s and the eighth harmonic beats 3.83 times a second, both read off the sound. The lowpass decides the fastest beat you hear: 5 Hz closed, 12 Hz open, and at 30 cents open it passes 15 Hz and the growl becomes grit. Play it, or let it play a bar of drum and bass.
The 808 is one sine with a pitch envelope. It starts at 147 Hz and lands on 49 in 155 ms, and the tail takes 2.4 s to fall 60 dB. A phone speaker plays 1% of it, and 84% of that is the first 50 ms. Clipping it hard buys the phone under 3 dB. Playing it an octave up buys 10. Play it on the keys, or let it play itself.