Low voice

I'm running a DivX file which has really low voice. The background music is allright. I've installed official DivX codec, DivX Audio filter, DirectVOB Sub, Koepi's XVID.

I'm checked the file with GSpot but I don't get the program. All I know is the sound is compressed as mp3.

Do I need to install anything else to play the file properly? I'm trying to install minimal number of codecs since I only want to play, not encode, so I 'm trying to avoid codec packs.