SvfCoef::allpass has the phase of a Linkwitz-Riley split at the same
frequency, so a crossover tree can keep its lower bands in phase with
the upper ones. The test checks it against a real LR4 split sample by
sample and for flat magnitude.
Lathe places EQ bands on harmonics 1-32 of the played note, so a cut on
harmonic 3 stays on harmonic 3 on every note. Temper normalises each
note's level before an oversampled shaper and tunes its floor, push and
bright filters to the note, so every note distorts the same.
The note tracker moves from Anvil into common-dsp, together with a
state-variable filter, 4x oversampler and harmonic meter. Anvil's
behaviour and editor render are unchanged.
docs/ideas.md collects all plugin ideas and their status.
nvrl