This little output plugin for xmms should let you output audio directly to the SGI Audio Library. It seems to work well on my O2 and Indy computers, but your mileage may vary. See the BUGS file for problems I've encountered so far. Please send me (Jesse Barnes) any bugfixes or improvements so that I can include them in later versions, and check the sgial home page for updates.
sgial-1.0pre: description + notes
xmms-IRIX, this plugin only works on IRIX 6.5 systems.
To auto-install this package, go back and click on the respective install icon.