1

##### Scientific Discussion / Re: Audio Summing Algorithm

Last post by**jsdyson**-

Actually, I have done something similar before -- by zeroing the phase of a given FFT (magnitudes the same, phase is zeroed -- all the same), and the result was pretty much unintelligble-- it was possible to detect some of the material, but didn't seem to be useful. At the time, I was playing with an FFT based compressor/expander design, and found that the results were generally not much better than an excellently designed 'linear gain control scheme with well managed attack/decay behavior.' The FFT approach is certainly helpful for NR, but AFAIK there are better techniques using a complex MDCT, where the blips and bleeps are better managed.

The comment about a true FFT being a linear transform is true -- add an FFT (each) of two signals and the result will be the same as an FFT of the sum of the actual time domain originals.

John