/ Examples / Filters / BandPass

BandPass

BandPass is a basic and simple band pass filter built atop ChucK's built-in BPF UGen. It is a 2nd order Butterworth Filter that shares the same controls and behavior with its siblings LowPass, HighPass and BandReject.

Remember that a filter's job is to reduce the amplitude of frequencies outside its sweet spot. When auditioning a filter configuration its wise to test it against a variety of input signals. The Noise UGen is handy for filter evaluation since it produces an all-frequency signal.

These filters are designed to pass frequencies in a range defined by their Cutoff and Quality (or Q) factor. The higher the Q the more strenuous the filter will be in respecting your cutoff guidance. However, as you increase Q you can cause underdamping of the signal which can lead to the dreaded overflow condition. For this reason it's common to constrain Q to the range 1-10 and carefully monitor/control the Gain.

In this graph, we see a CCGenerator that is automating the Cutoff parameter to produce an interesting effect.