In short, most MP3's are STEREO. The entire idea of MP3 is to shrink the filesize and there is no reason carry more channels than 99.99% of the people will have.
The reason the other setup may emit sound is that it's setup to just copy stereo out that back channels.
Your SKILL in finding all the settings may be needed, but I do not see any flaw in hardware or software here.
Bob
Why don't I have sound in my rear two speakers when I play mp3's?
All appears to work well other wise. The test on the Audigy control panel works. The voice says: "Front left. Front right. Rear right. Rear left."
The setting is correct on the panel: 4/4.1 speakers.
I get sound in the rear speakers during video games. Birds chirping, guns, etc...
I used two different players wmp and Music Match just to see if the problem was with the player, but neither let the rear speakers work.
I sometimes swap cards with an old Game Theater XP and that card plays sound out the back with mp3's.
Anyone have an idea why I have no sound in my rear speakers when I play mp3's using my SB Audigy 2 ZS?

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