Linear vs. circular convolution: multiplying two DFTs
DFT length M
Length of h, N
h
Listen: linear, then circular
Reset
Signal x
Exponential decay
Rectangular pulse
Ramp
Impulse response h
Echo
Decaying tail
Moving average
Lengths
Samples that wrap round
Smallest M with no wrap
Left and right arrows: M − 1 / M + 1. Up and down arrows: N
h
+ 1 / N
h
− 1.