Quick question about sound drivers (esp. snd_hda)

[Brian Waters]

It seems to me that under /dev, you can have the following
sound-related device files:

dspX
dspX.Y
(among others)

I'm having some trouble getting my sound to work (Dell Inspiron
E1705/Inspiron 9400 with Sigmatel STAC9220 codec). I've read the
manpages for snd and snd_hda (which is the appropriate driver), and
increased the verbosity of the drivers and read the kernel log and
/dev/sndstat, but I still can't quite wrap my head around everything.

What I'm wondering is: what exactly is the meaning of X and Y above?
I'm assuming that X comes from the "association numbers" in the
snd_hda driver, but I could be wrong. Please correct me!

Thanks,
Brian Waters