res(res, time) {
    var t = time || 0;
    if (typeof res === 'number') {
      this.biquad.Q.value = res;
      this.biquad.Q.cancelScheduledValues(this.ac.currentTime + 0.01 + t);
      this.biquad.Q.linearRampToValueAtTime(
        res,
        this.ac.currentTime + 0.02 + t
      );
    } else if (res) {
      res.connect(this.biquad.Q);
    }
    return this.biquad.Q.value;
  }
Controls either width of a bandpass frequency,
 or the resonance of a low/highpass cutoff frequency.

 @method  res
 @param {Number} res  Resonance/Width of filter freq
                      from 0.001 to 1000
 @param {Number} [timeFromNow] schedule this event to happen
                               seconds from now
 @return {Number} value Returns the current res value