# @suaveplan/audio-fx-plugin-eq - Parametric / shelving / high-pass / low-pass equaliser plugin for the @suaveplan/audio-fx-plugin-* family. Multi-band biquad implementation, sample-accurate parameter automation, preset round-tripping, universal.

Parametric / shelving / high-pass / low-pass equaliser for the `@suaveplan/audio-fx-plugin-*` family. Multi-band biquad implementation, sample-accurate parameter automation, Zod-validated preset round-tripping, universal (browser / server / offline / worklet identical).

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## Documentation tree

- [eq](./src/eq/eq.md) — `EQPlugin` is the 8-band parametric equaliser that anchors every mix bus, vocal chain, and master strip in the project.…
  - [eq](./src/eq/eq.md) — `EQPlugin` is the 8-band parametric equaliser that anchors every mix bus, vocal chain, and master strip in the project.…
- [schemas](./src/schemas/schemas.md) — The `eq.schemas` module owns every Zod schema that guards `EQPlugin`'s boundaries: construction options, single-band re…
  - [schemas](./src/schemas/schemas.md) — The `eq.schemas` module owns every Zod schema that guards `EQPlugin`'s boundaries: construction options, single-band re…
<!-- end:auto-docs -->

## Usage

```ts
import { createStorageUriResolver } from "@suaveplan/storage-uri";
import { PluginChain, DefaultBusRegistry } from "@suaveplan/audio-fx-plugin-base/chain";
import { EQPlugin, EQ_PRESETS } from "@suaveplan/audio-fx-plugin-eq";

const eq = new EQPlugin();
const chain = new PluginChain({
 buses: new DefaultBusRegistry(),
 plugins: [eq],
});

eq.applyPreset(EQ_PRESETS.vocalAir);
```

## Surface

| Symbol | Kind | Notes |
|---|---|---|
| `EQPlugin` | class | Concrete `AudioFxPlugin` implementation; extends `AbstractAudioFxPlugin` |
| `EQ_PRESETS` | const | Built-in factory presets |
| `EQBand`, `EQBandType`, `EQPluginOptions`, `EQPresetData`, `EQPresetName` | type | Public type surface |
| `EQBandSchema`, `EQBandTypeSchema`, `EQPluginOptionsSchema`, `EQPresetDataSchema`, `EQ_BAND_COUNT` | const / schema | Zod boundaries |
| `computeBiquad`, `BiquadCoeffs`, `BiquadState`, `identityCoeffs` | utility | Biquad math helpers (used internally; re-exported for DSP-curious consumers) |

## Composition

This package depends on `@suaveplan/audio-fx-plugin-base` for the `AudioFxPlugin` contract and the chain primitives. It declares no transitive `@suaveplan/audio-fx-plugin-*` deps — the dependency arrow points only at the foundation.

## Status

Replaces the `./eq` subpath of the bundled `@suaveplan/audio-plugins-fx`.