Summary of Flanging

A flanger provides uniformly spaced notches and/or peaks in the frequency response that move over time.

Parameters:

• Depth $g\in[0,1]$ -- controls notch depth
• Speed $f$ of notch movement
• Phase -- switch to subtract instead of adding the direct signal with the delayed signal

Possible additional parameters include

• Average Delay $M_0$
• Excursion or Sweep $A$ -- amount by which the delay-line grows or shrinks
• Feedback or Regeneration $a_M \in(-1,1)$ -- feedback coefficient from output to input

Drawbacks to Flanging:

• Exponentially spaced notches (uniformly spaced on a log frequency scale) would sound more uniform perceptually
• Uniform peaks can impose ``resonant pitch''
  (sounds like being inside a resonant tube)