# Reverb · zvuk

zvuk v1.14.1 · MIT · https://zvuk.schmooky.dev/fx/reverb/

Convolution reverb with synthetic-IR fallback. Use a real impulse response for spaces, or skip it for ambient wash.

FX

# Reverb

Convolution reverb with synthetic-IR fallback. Use a real impulse response for spaces, or skip it for ambient wash.

Two sounds recorded in the same room share something no amount of EQ will fake, and a mix where nothing shares a room sounds like a pile of files.

A [`Reverb`](/api/Reverb/) wraps a `ConvolverNode` with dry/wet mixing and pre-delay. Pass an `impulse` AudioBuffer to put your sounds in a real measured space. Omit it and zvuk generates a synthetic exponential-decay noise impulse instead, which costs nothing to ship and carries far less character, but holds up fine as atmosphere.

## API surface

Reverb + ReverbConfig ts

```
class Reverb implements FxInsert {
  readonly input: GainNode;
  readonly output: GainNode;
  bypassed: boolean;

  setWet(mix: number): void;          // 0..1
  setImpulse(buffer: AudioBuffer): void;
  dispose(): void;
}

interface ReverbConfig {
  wet?: number;                       // default 0.3
  impulse?: AudioBuffer;              // your own IR
  decay?: { seconds?: number; preDelay?: number };
}
```

## Live demo

Wet mix slider, decay length (regenerates the IR), bypass toggle.

Use your own sound

bus output (post-reverb)idle

wet0.30

decay (s)1.50

engaged

Unlock & start chimes

## Recipes

### Synthetic IR

ts ts

```
import { Reverb } from '@schmooky/zvuk';

// Synthetic IR — ~free, fine for atmosphere.
const verb = new Reverb(engine.context, {
  wet: 0.3,
  decay: { seconds: 1.5, preDelay: 0.02 },
});
engine.bus('music').addFx(verb);
```

### Real impulse response

ts ts

```
// Real impulse response — load like any other audio asset.
const irBuf = await fetch('/ir/cathedral.wav')
  .then((r) => r.arrayBuffer())
  .then((ab) => engine.context.decodeAudioData(ab));

const verb = new Reverb(engine.context, { wet: 0.4, impulse: irBuf });
engine.bus('music').addFx(verb);
```

### Wet driven by a Parameter

ts ts

```
// Drive wet from a Parameter so multiple things tilt with one knob.
const intensity = engine.parameter('intensity', 0.3);
intensity.bindTo((v) => verb.setWet(v), { from: 0.1, to: 0.6 });
```

## Pitfalls

Don't reverb SFX.

Individual hits get smeared and mushy. Reserve reverb for the long-tailed sources: music, ambience, voice. SFX want to land sharp.

Don't ship a 5-second IR for a UI bus.

Convolution cost scales with impulse length times sample rate, and a five second impulse at 48 kHz costs the same every frame whether the bus has audio on it or not. Keep impulses under two seconds unless you genuinely need a cathedral.

## Related

-   [FX index](/fx/)
-   [Parameter](/concepts/parameter/) drives the wet amount from a knob.