process(src, freq, res, time) {
    src.connect(this.input);
    this.set(freq, res, time);
  }
Filter an audio signal according to a set
 of filter parameters.

 @method  process
 @param {Object} src An object that outputs audio
 @param {Number} [freq] Frequency in Hz, from 10 to 22050
 @param {Number} [res] Resonance/Width of the filter frequency
                       from 0.001 to 1000