tags: dsp audio-programming audio
Feedback comb filter
The feedback comb filter uses feedback in its design as opposed to a feedforward signal like its counterpart.
The feedback comb filter is an example of an [IIR] digital [filter]. It can be regarded as a computational physical model of a series of echoes.
Implementation
Comb filters are just [delay lines] with [feedback]
- feeding signal into itself with an extremely short delay time, to the point of hearing a periodic waveform
- any [partial] with aligns with the inverse of the delay time (and all the [harmonic]s of that partial) will experience 100% [constructive interference]
- creates peaks in the [spectrum]
- conversely, any harmonic that has 1.5/2.5/3.5/etc. times the [frequency] of the original partial will experience 100% [destructive interference]