I just encoded the Beatles' Anthology albums with alt-preset extreme, and many of the demos and live recordings end up with very low bitrates. Quite a few tracks, in fact, end up with a flat 128 Kbps for the entire file--now that's stretching the definition of variable bit rate!
Now, I understand APX is not selling my music short. If it says I only need 128 Kbps for the entire file, then I believe it. I also understand that the fact that many of these tracks are mono means it can save a lot of bits. Would it be fair to say that encoding a "mono" file (even though it technically has two channels) at 128 Kbps is comparable encoding a stereo file at 256 Kbps? Or is there too much overhead for that? Basically I am just trying to understand what is so different about this music that it needs so little bits to encode it, and would like to get reassurance that i do not need to beef up my encode to get better quality for this music. Thanks.