Restoring audio quality by differencing mono channels? 2016-09-28 13:48:04 I have a recording for which the master tape and safety copy have both been lost.(un)fortunately, the only surviving version is a mediocre quality 128kbps mp3 made about 10 years ago. It's passable, but not great - there is audible compression artifacting, especially noticeable on things like cymbals, which sound rather watery.This mp3 is dual mono. Due to an error on the engineer's part, none of the tracks were panned, and thus instead of being a stereo mix-down, the mp3 has two channels of the same mono content.However, when I invert one of the two channels and sum them to mono, the result is not silence - there is a difference between the channels. Presumably the mp3 encoder treated each channel slightly differently.See the attached FLAC file: this is the resultant signal, which seems to be composed entirely of digital compression artifacts.My question to you is this: is there some way to use this resultant information to restore/improve the quality of this file? Some sort of averaging or differencing perhaps? Is this pie-in-the-sky thinking, or something that's theoretically possible? Has anybody ever attempted something like this?