Flanger

• The well known flanger is a feedforward comb filter with a time-varying delay $M(n)$ (see flanging.mov).

• Flanging, used in recording studios since the 1960s, creates a rapidly varying high-frequency sound by adding a signal to an image of itself that is delayed by a short, variable amount of time.

• Flanging was accomplished in analog studios by summing the outputs of two tape machines playing the same tape.

  Figure 1: Two tape machines are used to produce the flanging effect.

  

• By touching (and releasing) the flange on one supply reel, it would s to slow it down (and speed it up).