Effect registry
Every effect, its parameters and the usable range of each. Values outside a range are clamped on read, so anything that parses is safe to realise. AUTO marks a parameter an automation lane can drive; anything unmarked cannot move over time (see the note at the bottom).
Generated from HF_AUDIO_FX in @hyperframes/core/audio-fx, which is the source
of truth — if this table and the code disagree, the code is right.
Filter — which frequencies a track may occupy
| Effect | Parameter |
|---|---|
highpass |
frequency 20–20000 Hz (300, log) AUTO · q 0.1–20 (0.707, log) AUTO · poles 1|2 (2) |
lowpass |
frequency 100–20000 Hz (8000, log) AUTO · q 0.1–20 (0.707, log) AUTO · poles 1|2 (2) |
peaking |
frequency 20–20000 Hz (1000, log) AUTO · gain −40–40 dB (0) AUTO · q 0.1–20 (1, log) AUTO |
lowshelf |
frequency 20–2000 Hz (200, log) AUTO · gain −40–40 dB (0) AUTO |
highshelf |
frequency 500–20000 Hz (4000, log) AUTO · gain −40–40 dB (0) AUTO |
q is bandwidth — higher is narrower. poles is the slope: 2 is the usual
biquad (12 dB/oct), 1 is gentler (6 dB/oct). Shelving filters have no q: the
Web Audio spec leaves it unused for them, so a control would have moved nothing.
Dynamics — how level behaves over time
| Effect | Parameter |
|---|---|
gain |
gain −60–12 dB (0) AUTO |
compressor |
threshold −60–0 dB (−24) · ratio 1–20 (4) · attack 0.01–2000 ms (20, log) · release 0.01–9000 ms (250, log) · knee 1–8 (2.83) · makeup 0–36 dB (0) · mix 0–1 (1) |
limiter |
limit −24–0 dB (−1) · attack 0.1–80 ms (5) · release 1–8000 ms (50, log) · level_out −24–24 dB (0) |
gate |
threshold −80–0 dB (−35) · range −80–0 dB (−24) · ratio 1–20 (10) · attack 0.01–9000 ms (1, log) · release 0.01–9000 ms (100, log) · knee 1–8 (2.83) |
Cuts on gain go to −60 dB, boosts stop at +12: it is a level stage for making
room, and a chain that could add 40 dB would clip long before that was useful.
knee of 1 is a hard corner, higher eases into it. mix below 1 blends the dry
signal back in (parallel compression). range is how far down the gate pulls
when closed — a gate that pulls all the way to silence sounds like a switch.
Nonlinear — changes the waveform's shape
| Effect | Parameter |
|---|---|
saturate |
type tanh|atan|cubic|exp|alg|quintic|sin|erf|hard (tanh) · threshold −40–0 dB (−6) · output −24–24 dB (0) AUTO · oversample 1–8× (4) |
bitcrush |
bits 1–32 (8) · samples 1–250× (1) · mix 0–1 (1) |
tanh is the gentlest curve and hard is outright clipping. Higher oversample
costs more CPU and keeps aliasing down. samples repeats each sample N times — a
crude downsample, which is where the lo-fi character comes from.
Time — space and width
| Effect | Parameter |
|---|---|
delay |
time 1–5000 ms (250, log) AUTO · feedback 0.01–0.95 (0.35) AUTO · mix 0–1 (0.4) AUTO |
reverb |
size 0.05–1 (0.7) · damping 0–1 (0.5) · wet 0–1 (0.35) AUTO · dry 0–1 (0.7) AUTO |
chorus |
delay 1–100 ms (7) AUTO · depth 0–10 ms (2) AUTO · speed 0.01–10 Hz (1) AUTO · mix 0–1 (0.5) AUTO |
phaser |
in_gain 0–1 (0.4) AUTO · out_gain 0–2 (0.74) AUTO · delay 0.1–5 ms (3) · decay 0–0.99 (0.4) · speed 0.1–2 Hz (0.5) AUTO · type 0|1 (0) |
Reverb convolves a generated impulse, and both preview and render generate the
same one — so a room is reproducible without shipping an impulse file. Higher
damping rolls the top off the tail faster, which is what makes a large room
sound like a soft one. feedback near the top of its range is a very long tail;
it is bounded below 1 because at 1 it never decays.
Why some parameters cannot be automated
Automation is handed to the audio thread once, as native AudioParam ramps and
curves, which is what keeps it sample-accurate and identical between preview and
render. A parameter can therefore only be automated if an AudioParam backs it.
Three kinds do not:
- worklet processor options —
compressor,limiter,gateandbitcrushare AudioWorklets configured wholesale, so none of their parameters are automatable at all. - a WaveShaper curve —
saturate'stype,thresholdandoversamplerebuild the curve; only itsoutputstage is a real param. - a convolution impulse —
reverb'ssizeanddampingregenerate the impulse;wet/dryare gain stages and automate fine.
To make one of those behave differently over time, automate a gain stage
around it instead: a lane on a gain before a compressor changes how hard the
compressor is driven, which is most of what automating its threshold would have
done.