Comb

This is a called a comb filter, because of the shape of its frequency spectrum looks a bit like the teeth of a comb. Filters are used to shape noise or other sounds, so that they become louder at some frequencies and softer at others. This gives the sound some added character.

Mathematically, a general comb filter is of the form input[t] + g1 * input[t - m1] - g2 * output[t - m2]. If g1 = 0, this is called a feedforward comb filter, and if g2 = 0, this is called a feedback comb filter.

What happens if you change the delay?

---