combFilter-2.js

class LowpassCombFilter extends CompositeAudioNode {
    get resonance () {
        return this._gain.gain;
    }
    get dampening () {
        return this._lowPass.frequency;
    }
    get delayTime () {
        return this._delay.delayTime;
    }

    constructor (audioCtx, options) {
      super(audioCtx, options);
      const {delayTime, resonance: gainValue, dampening: frequency} = options;
      this._lowPass = new BiquadFilterNode(audioCtx, {type: 'lowpass', frequency})
      this._delay = new DelayNode(audioCtx, { delayTime });
      this._gain = audioCtx.createGain();
      this._gain.gain.setValueAtTime(gainValue, audioCtx.currentTime);

      this._input
      .connect(this._delay)
      .connect(this._lowPass)
      .connect(this._gain)
      .connect(this._input)
      .connect(this._output)
    }
  }