Static in sound playing any video rips

I get a static hiss when I try to play the disks through XBMC but work fine when played through MPlayer OSX Extended. I recall reading something about the BBC Blu-Ray and sound but can't find anything addressing this. Right NOTHING (whether .mkv .mp4 or .vob) plays sound through XBMC on my Mac Mini 10.8.3 and Frodo

Thanks, Rich