So my plan was to use squeezeslave on a nslu2 slug with a terratec 7.1 usb soundcard and my old 5.1 soundsystem to play music in my bathroom (front left/right), the anteroom/hallway (rear left/right) and the toilette (center).

Now after fiddling a while and finding out that etch doesn't even have the surround51 preconfigs, I upgraded to debian lenny and FINALLY came up with an asound.conf which does what I want.

Only thing I might improve on is getting the mixing of left/right for the center channel to work, and possibly some filtering for the subwoofer – however I am not exactly sure if that's a good idea given the limited cpu power of the slug.

Anyways here's the asound.conf – note that squeezeslave refuses to work without a sample rate of 44100.

upmix output is outputting the stereo signal to all channels, the rest is for adressing/splitting between individual channels.

So i.e. you could run one application outputting to the frontspeakers and one to the rear.

Thanks to some guy on the internet (i am sorry I can't find the link anymore) for the asound.conf I based this on (it had everything apart from the combined upmix output)

pcm.dshare {
	type dmix
	ipc_key 2048
	ipc_key_add_uid false # let multiple users share
	ipc_perm 0660 # IPC permissions (octal, default 0600)
	ipc_gid audio
	slave {
		pcm "hw:0,0"
		rate 44100
		format S16_LE
		period_time 125000
		period_size 6000
		buffer_size 24006
		channels 8
	}
	bindings {
		0 0
		1 1
		2 2
		3 3
		4 4
		5 5
		6 6
		7 7
	}
}
 
pcm.upmix {
	type plug
	slave {
		pcm "dshare"
		channels 8
	}
	ttable.0.0 1
	ttable.1.1 1
	ttable.0.4 1
	ttable.1.5 1
 
	ttable.0.2 1
	ttable.1.3 1
 
	ttable.0.6 1
	ttable.1.7 1
}
 
pcm.frontx {
	type plug
	slave {
		pcm "dshare"
		channels 8
	}
	ttable.0.0 1
	ttable.1.1 1
}
 
pcm.centersub {
	type plug
	slave {
		pcm "dshare"
		channels 8
	}
	ttable.0.2 1
	ttable.1.3 1
}
pcm.rearx {
	type plug
	slave {
		pcm "dshare"
		channels 8
	}
	ttable.0.4 1
	ttable.1.5 1
}
 
pcm.sidex {
	type plug
	slave {
		pcm "dshare"
		channels 8
	}
	ttable.0.6 1
	ttable.1.7 1
}