For our project we will be implementing a variable flange effect as a MATLAB function. This effect is the result of two identical signals bening added together but with one passing through a variable time delay. The resulting phase differences produce harmonicly linear peaks and troughs throughout the frequency spectrum. This effect was first discovered accidently with two out of sync tape reals. Today it can be implemented in the digital realm with variable inverse comb filters.

Also, an allpass filter is used to allow a continuous value for the sample delay instead of it being dependent on integers. As a result, delay can be any function i.e. a LFO, signal content, external gate. The magnitude (depth) can also be varied likewise. A feedback loop can also be added or subtracted which produces another set of variable poles or zeroes.

A simple block diagram: