My friend and I puzzled over this at work today. He thought that a mono wav was basically a stereo wav with a hard pan. I had noticed that stereo wavs were twice as big as monos. I assumed that actually a stereo wav was like 2 mono files. Now I'm wondering if that's true.
I've read mp3 processor reviews and noticed an interesting 'encoding' criteria. The ability to reproduce an accurate image of the wav's pan field. Is the degredation of the stereo image after compression due to mp3 compression, or do the algorythms somehow sum both stereo channels, possibly along with generating code data for stereo playback?
I wish I had more knowledge instead of these guesses! I haven't tested this yet but I bet the mono mp3s are smaller than the stereo mp3s, but by over 50%.
I've also heard that if you dig a hole, there may be too much or too little dirt left over when filling it up. They say it all depends on the phase of the moon.
Hell, I saw a man use dowsing rods last week. If I see him again, I'll ask him about the mp3s!