Hi I'm using alsa in 5.1 mode.

pcm.ch51dup {
         slave.pcm surround51
         slave.channels 6
         type route
         ttable.0.0 1
         ttable.1.1 1
         ttable.0.2 1
         ttable.1.3 1
         ttable.0.4 0.5
         ttable.1.4 0.5
         ttable.0.5 0.5
         ttable.1.5 0.5
}

The 5.1 mode works but I get sqeaky sound in one of the speakers but it's not there once I turn it back into stereo mode and turn on the matrix mode. The speakers are the Logitech X-540. I do have onboard sound but I've disabled via the sound preferences applet in gnome

I'm using a Audigy2 ls with ubuntu lucid. Why is this? The asoundrc is the only file I've played with. I enable 5.1 using the sound preferences applet provided by gnome.