Reverb.js

Append reverb effect to audio source.

This script is originally a spin out of sf2synth.js's reverb effect.

Sample

• https://logue.dev/Reverb.js/
• https://logue.dev/Reverb.js/localaudio.html

Syntax

const reverb = new Reverb(ctx, {
  /**
   * Randam noise algorythm
   * @see {@link https://github.com/thi-ng/umbrella/tree/develop/packages/random}
   */
  randomAlgorithm: SYSTEM;
  /**
   * IR (Inpulse Response) colord noise algorithm (BLUE, GREEN, PINK, RED, VIOLET, WHITE)
   * @see {@link https://github.com/thi-ng/umbrella/tree/develop/packages/colored-noise}
   */
  noise: Noise.WHITE,
  /** IR source noise scale */
  scale: 1;
  /** Number of IR source noise peaks */
  peaks: 2;
  /** Amount of IR decay. 0~100 */
  decay: 5,
  /** Delay time o IR. (NOT delay effect) 0~100 [sec] */
  delay: 0,
  /** Filter frequency. 20~5000 [Hz] */
  filterFreq: 2200,
  /** Filter Q. 0~10 */
  filterQ: 1,
  /**
   * Filter type. 'bandpass' etc.
   * @see {@link https://developer.mozilla.org/en-US/docs/Web/API/BiquadFilterNode/type}
   */
  filterType: 'lowpass',
  /** Dry (Original Sound) and Wet (Effected sound) raito. 0~1 */
  mix: 0.5,
  /** Reverse IR. */
  reverse: false,
  /** Time length of IR. 0~50 [sec] */
  time: 3,
});

Usage

// Setup Audio Context
const ctx = new window.AudioContext();

// iOS fix.
document.addEventListener('touchstart', initAudioContext);
function initAudioContext() {
  document.removeEventListener('touchstart', initAudioContext);
  // wake up AudioContext
  const emptySource = ctx.createBufferSource();
  emptySource.start();
  emptySource.stop();
}

// Setup Reverb Class
const reverb = new Reverb(ctx, {});

// put Audio data to audio buffer source
const sourceNode = ctx.createBufferSource();
sourceNode.buffer = [AudioBuffer];

// Connect Reverb
reverb.connect(sourceNode);
sourceNode.connect(ctx.destination);

// fire
sourceNode.play();

Testing

This project includes a comprehensive test suite to ensure reliability and code quality.

Test Coverage

• Statement Coverage: 100%
• Function Coverage: 100%
• Branch Coverage: 90.56%
• Line Coverage: 100%

Test Structure

The test suite is organized into several categories:

• Unit Tests: Individual method and property testing

  • src/__tests__/Reverb.test.ts - Main Reverb class tests
  • src/__tests__/NoiseType.test.ts - Noise type definition tests
  • src/__tests__/OptionInterface.test.ts - Configuration interface tests

• Integration Tests: Component interaction testing

  • src/__tests__/integration.test.ts - Cross-component integration tests

• End-to-End Tests: Real-world usage scenarios

  • src/__tests__/e2e.test.ts - Practical implementation scenarios

Test Features

The test suite covers:

• ✅ Constructor with default and custom options
• ✅ Audio node connection and disconnection
• ✅ Parameter validation and error handling
• ✅ All reverb parameters (mix, time, decay, delay, reverse)
• ✅ Filter configurations (type, frequency, Q-factor)
• ✅ Noise algorithm variations (white, pink, brown, blue, violet, red, green)
• ✅ Performance testing with multiple instances
• ✅ Edge cases and boundary conditions
• ✅ Real-world scenarios (guitar, vocal, drum reverb settings)

Running Tests

# Run all tests
pnpm test

# Run tests once
pnpm test:run

# Run tests with coverage report
pnpm test:coverage

Test Environment

• Vitest - Fast Vite-based test framework
• Happy-DOM - Browser environment simulation
• Web Audio API Mocking - Complete audio context simulation
• TypeScript Support - Full type checking during tests

CDN Usage

Not really intended for use with a CDN.

The dependent libraries @thi.ng/colored-noise, @thi.ng/random and @thi.ng/transducers need to be loaded separately.

Reference

• Web Audio API
  • Web Audio API 日本語訳
• コンボルバーの使い方
• WebAudio の闇
• @thi.ng/colored-noise

License

©2019-2025 by Logue. Licensed under the MIT License.