what a legacy....
well im using debian which is requires some loving for ut2004 to work properly
firstly one removes the ut2004/System/libopenal.so and links it to /usr/lib/libopeal0.so
then similarly remove and link the libSDL
but you need to force openal to use alsa... (for the longest time i thought it was just my soundcard sucking - in addition to the oss layer sucking)
http://ubuntuforums.org/showthread.php?p=2325660
one needs to force alsa in the ~/.openalrc file
ie
echo "(define devices '(driver))" > ~/.openalrc
# native (OSS)
sdl (Simple DirectMedia Layer backend, see above Q/A)
arts (arts backend)
esd (ESounD backend)
alsa (ALSA)
waveout (Output a wav file)
null (no sound)
echo "(define devices '(alsa))" > ~/.openalrc
UseDefaultDriver=False