Hello, What is the best way to subtract a known sample from given audio i.e. extract/reconstruct the original.wav from final.wav when final.wav has been created with commands: sox knownsample.wav knownsample_delay_gain.wav pad 0 vol sox -m original.wav knownsample_delay_gain.wav final.wav original.wav is not anymore available. knownsample.wav and final.wav are available. pad delay and the vol parameter are known _roughly_ (X =~10ms, Y=~0.1) regards, Mikk00 PS1, I can reconstruct the original with the process below but this method is very cumbersome: repeat { come up with some guessed X and Y sox knownsample.wav knownsample_delay_gain.wav pad 0 vol - // is also inverted sox -m -v 1 original.wav -v 1 knownsample_delay_gain.wav final.wav stat } until RMS amplitude reported by stat has reached local minimum I am after more streamlined way to remove known sample from given audio. PS2, The original problem is a two musical instruments recorded simultaneously in the same space. They have their own mics but the other instrument is audible in each recording. I want to remove the "wrong instrument" from each recording and have clean audio for both instruments.