Quoting Jonty Needham <jmn20@xxxxxxxxxx>: > Many thanks for the replies, but one thing I don't quite understand. I'm > not sure what you mean by "left -right". Would that not be reversing the > polarity of the signal and then adding them together, or am I missing > something critical. Sorry, my haste got the better of me last time :) Do the left minus right operation first. This way you'll end up with what Ismael told you: ths "karaoke" signal with all components common to l/r removed. To get the reverse (only the common components), you need to remove the karaoke signal from a mono version of the original signal. I'm not sure how well this will work.. Tell us if you decide to try! ;) Sampo
