[PlanetCCRMA] everything is installed, but no sound.

[youyou]

i don't understand, i've installed all alsa packages, i've heard sound 
when testing the sound in kde sound server, so i've tried to run jack 
and it failed, i've tried to load a wav file in kdeplayer, it said
"open audio is not possible, make sure you have selected right output 
plugin, make sure that no other app is using sound, make sure your 
soundcard is configured"
i don't know wich pulgin i must choose, did i forget something in ccrma 
method?
my sound card is configured, if it wasn't i wouldn't hear sound.
i don't know if some other sound app is running...
i must have forgotten something very simple, alsamixer worked, then i 
tried alsaplayer, it didn't work, it just froze, i had to kill the program.