MATH·77
Every other kick tool here piles material into a hit. This one refuses all of it. There is no noise, no sample and no random number in the engine, and the same numbers give the same bytes on any machine, forever. The voices are of two kinds: a series, where every sample stands on its own, and a recurrence, one line applied to its own last answer. Both are written down. Only one of them can sound like material.
The reading under the wave is spectral flatness, the ratio of the geometric mean of a spectrum to its arithmetic mean. A pure sine measures 0.000 and white noise 0.850. Eleven measured neo bochka tracks sit at 0.28 to 0.63, because their kicks had been hit, bounced and resampled and every pass left rubbish between the harmonics. This instrument reaches all of it, and the knob that walks it is not the one I expected. Shaping never fills the space between the partials, because a waveshaper can only ever make more harmonics: a harmonic series folded to the stop still reads near zero. STIFFNESS is what fills it, by pulling the partials off whole multiples so their crowd stops lining up, and it walks 0.05 to 0.12 to 0.42 to 0.48. And the VOICE knob is the other road to it: a series can only ever put energy on multiples of the note, and every shaper here leaves the harmonics standing 47 to 51 dB over the space between them however hard it is pushed. The five maps do the opposite, reading −3 to −11 dB, which is where recorded kicks read and no waveshaper reaches. None of it is random, and all of it repeats exactly.
The first lesson of that study opens on one sentence: their kick is a tuned note rather than a hit. DAMP is that sentence as a knob. At zero the partials die together and the spectrum stands still while the sound goes, which is a note; measured, its centre of gravity moves 5% over three hundred milliseconds. Turned up, the upper modes give their energy first and the centre falls 55%, which is the whole of what an ear calls a hit. A struck thing cannot help doing it and a held note cannot do it at all.
What the first version lacked was the hit itself. Every sum started dying on its first sample, so the first 100 ms of the ten starting points sat 4.4 to 9.2 dB under the peak. Three terms answer it. HOLD keeps the level at the top before it falls. DRIVE is a tanh scaled so the peak stays put and only the tail rises. CLICK is a second pitch fall, from 3200 hz into the body in about a millisecond, and the body steps aside for it rather than stacking under it, so a full click costs the body 0.2 dB instead of 4. The five new starting points keep their first 100 ms within 2.5 dB of the peak. Every hit now leaves at −1 dBFS, centred on zero and faded over its last 6 ms, so LENGTH no longer clicks.