Anvil gets a sidechain input named Kick. With Kick lock on, kicks are
found on the undelayed sidechain, so with the lookahead each hit ducks
the sub (Duck, Release) when the delayed kick plays and restarts the sub
at Phase, shifted by Offset (-30 to +30 ms, also before the kick).
The Audition steps the offset from -30 to +30 ms, 4 kicks each, and
measures how kick and sub sum below 150 Hz after each hit; Keep takes the
offset heard. On a 55 Hz kick burst against a 55 Hz sub the sum peaks at
0 ms (+2.4 dB) and nearly again one period away (+/-20 ms), so the bars
check the choice by ear rather than make it.
Adds a detuned copy of the bass whose beating stays on the tempo grid on
every note. The chosen harmonic k beats once per Rate note value, and
harmonic n beats n/k times as fast, so every harmonic is on the grid.
- The copy is read from a delay line whose delay falls one period of the
tracked note per beat cycle (r = 1 + B/(k f0)) and jumps back exactly
one period, crossfaded over 6 ms. On a periodic note the jump has no
seam: the output matches the ideal sum within 0.003 on harmonics 1-4.
- The delay follows the host's beat position, shifted by the lookahead,
so beat peaks land on the grid; free-running when stopped.
- Low cut: LR4 high-pass on the copy, the bass split by the same
crossover, so the sub does not beat and keeps its level.
- Depth, Width, Phase, Gate, Output, Snap, Bypass. Pitch from audio
(about 67 ms lookahead) or MIDI.
- Editor: one bar of the beat per harmonic with the grid and a playhead.
- Catalog, workflows, editor-check, docs, signal chain and site copy.
Upward and downward compression in four bands whose edges are harmonic
numbers of the tracked note (default 1, 2-4, 5-16, 17 and up), so the
same setting squashes the same harmonics on every note. A fixed-band
OTT puts harmonic 2 of F1 and of C2 in different bands.
- Three Linkwitz-Riley splits at sqrt(k(k+1)) x f0 with allpass
compensation; at Depth 0 the bands sum within 0.05 dB.
- Band level is the RMS over one period of the note, so heavy settings
do not ripple at f0: a 40 Hz sine at Drive +12 dB, Time 10 % gets no
harmonics above -110 dB.
- At Depth 100 % on a saw, harmonics 1-12 change by the same amount on
F1, C2 and G2 (within 0.2 dB).
- Depth, Drive (on the detector only), Upward, Downward, Time, a gain
per band; edges Low 1-8, Mid 2-16, High 3-48 with four splits.
- Pitch from audio with about 67 ms lookahead, or from MIDI.
- Editor: harmonic ruler with draggable edges, level and gain per band.
- Catalog, workflows, editor-check, docs, signal chain and site copy.
docs/chain.md gives the plugin order for a bass track and the bus, the
latency each plugin adds, and the measured octave error of downstream
note trackers after Knurl: from C2 up the tracker reads an octave low
about 85 % of the time, and timing jitter adds 5-25 false note starts
per second. Knurl and Anvil guides point there and recommend MIDI as
the pitch source after Knurl.
docs/ideas.md gains the production-flow audit, next steps for every
released plugin, new ideas (Forge, Planish, Quench, Scribe, Bevel,
Peen) and a build order.
nvrl