@audio/expander
Status pending calibration
npm0.2.2licenseMIT
Downward expander: reduces gain below threshold by (T-L)·(ratio-1) dB,
import expander from '@audio/dynamics-expander'
Downward expander (mode: 'downward', default) — a softer gate. Below threshold, gain is reduced by (threshold − level) × (ratio − 1) dB, clamped at range.
mode: 'upward' switches to upward expansion — the de-compression complement, raising gain above threshold instead of cutting it below. Classical substrate for de-limiting: transient-aware upward expansion restores crest factor a brickwall limiter (or an over-eager mix bus compressor) flattened. Same four-quadrant taxonomy as compressor's upward mode (Giannoulis/Reiss; Izhaki, Mixing Audio).
import expander from '@audio/dynamics-expander'
expander(data, { threshold: -30, ratio: 2 })
// de-limiting: expand transients back out above threshold
expander(data, { mode: 'upward', threshold: -20, ratio: 1.5, range: 20 })
| Param | Default | |
|---|---|---|
mode |
'downward' |
'downward' | 'upward' |
threshold |
-30 |
dB |
ratio |
2 |
— |
knee |
6 |
dB |
range |
-40 (downward) / 20 (upward) |
dB, max reduction (downward, negative) or max lift (upward, positive) |
attack |
5 |
ms |
release |
50 |
ms |
Use when: gentle noise-floor suppression without the abruptness of a gate (downward); restoring dynamics to over-compressed or over-limited material (upward).
Not for: hard removal of sound between phrases — use gate.
Part of @audio/dynamics — the dynamics family umbrella. This README is generated from the umbrella docs.
MIT © audiojs