Flanger

An effect that mixes the signal with a very short, continuously swept delay, producing a metallic whooshing sweep with evenly spaced peaks across the spectrum.

The delay is short enough that the copies comb-filter against the original, reinforcing some harmonics and cancelling others, and as the delay time moves those notches travel up and down the frequency range. Feedback deepens the effect into a hollow, jet-like sound, which is its signature. The difference from a chorus is the delay length and the degree of modulation: flanging is shorter and more extreme.

Example: a slow sweep with high feedback across a distorted power chord gives the wide, hollow motion typical of a lot of rock guitar.

Flanger

See also