ALSA Surround - Rear channels
 

Please forgive my ignorance if this has been asked before, I couldn't find anything.

I'm trying to get my 4.1 surround sound working on Slackware 10, kernel 2.4.x.
My sound card is a Sound Blaster Live!, and I'm using ALSA.
The module loaded by alsaconf is snd-emu10k1.

I've tried the settings in alsamixer, but none seem to help.
I'm using the speaker-test program from:
alsa-project.org slash ~james slash speaker-test
to test my configuration, using the device surround41 and specifying 4 channels
speaker-test -Dsurround41 -c 4
This program plays tones for every channel, like Front Left, Front Right, Rear Left and Rear Right. However, my Rear Left speaker plays the same tone as my Front Left speaker, although at a very low volume. The same is true for my Front- and Rear Right speakers.
There is only silence when speaker-test plays the Rear tones.

This is not limited to speaker-test, though. It seems as if the front channels are just duplicated to the rear channels, at a lower volume. I can't change that volume, either, not even with the controls on the speakers themselves.

Any help would be greatly appreciated.