This “mixes” the left and the right channels to create a single mono track. This is most useful when the stereo track has very different left / right channels and you want both sides in the mono version.
This literally splits the stereo track so that the upper (left) channel of the stereo track becomes one mono track, and the lower (right) channel becomes another mono track.
This is particularly useful if you have a stereo recording with one good channel and one bad channel. You would (of course) discard the bad channel. It is also useful when the two channels in the stereo track are the same, or very nearly the same, because it is so much quicker than mixing down to mono.
Thanks for that very good explanation. Is there a way to analyze each track to see how similar they are? The look the same and basically sound the same. It’s an ebook so I assume they’re basically the same, but I’d be curious analyze them in a more precise way. Thanks.