sw-synth

Lightweight sound synthesizer designed for real-time user interaction using the Web Audio API.

Installation

Install from npm:

npm install sw-synth
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Quick start

import {Synth, defaultParams} from 'sw-synth';

const context = new AudioContext({latencyHint: 'interactive'});
const synth = new Synth(context, context.destination);

synth.maxPolyphony = 6;
synth.voiceParams = defaultParams();

const noteOffs = new Map<string, () => void>();
window.addEventListener('keydown', (event: KeyboardEvent) => {
  const pitch = parseInt(event.key, 36) % 24;
  const frequency = 440 * 2 ** (pitch / 12);
  const velocity = 0.2;
  noteOffs.set(event.key, synth.noteOn(frequency, velocity));
});

window.addEventListener('keyup', (event: KeyboardEvent) => {
  const noteOff = noteOffs.get(event.key);
  if (noteOff) {
    noteOff();
    noteOffs.delete(event.key);
  }
});
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API overview

The package exports four synth classes:

• Synth: finite polyphony with standard Web Audio OscillatorNode voices.
• UnisonSynth: finite polyphony with stacked detuned oscillator voices.
• AperiodicSynth: finite polyphony using AperiodicWave from aperiodic-oscillator.
• BufferSynth: finite polyphony driven by user-provided AudioBufferSourceNode factories.

Voice parameter helpers are also exported:

• defaultParams()
• defaultUnisonParams()

Documentation

• Hosted docs: https://xenharmonic-devs.github.io/sw-synth
• Generate docs locally:

npm run doc
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TypeDoc output is written to ./docs.