Got a problem with AC3 filter sound

[Desertfox92]

I've just got a 5.1 surround set and they all 5 boxex sub are working, how ever I wanted something else then the Realted HD audio configuration tone when you test your speakers. I have this dolby digital sound test disc which hass all those intros from THX, DTS dolby etc... but I wasn't getting surround sound.(sound that should be behind me was in front of me) so I went to the AC3 filter config and saw that the input was 5.1, but the output was 2.0 so I changed it to 3/2 SW (3 front 2 back sub) (as the manuel also suggests) but now all the sounds are really low qualety and its really loud, especially voices main sounds. the output is now the same is the input (5.1) but I don't think its supposed to be like this.

Thanks.

edit: just read the sticky about things you should post so here we go:

BS player 2.40 april 2009 build

Windows vista 64bit
Dual core 2.8 ghz
ATI HD4850 512mb
4 gig dual channel 800mhz ram