Sound card problem

[guitarman]

Hi,
My sound card seems to be really messed up idk what happened but after pluging anything into the subwoofer/center channel output on my audigy 2 card my sound gets all distorted with lots of hissing. If you plug it in about half way you can get some sound out of the subwoofer and the hissing and distrtion goes away but plugging it in all the way just screw it all up for some reaons. Also it seems like differnt thing you plug into it produce different type of distortion, like if you plugin a pair of headphons the tone seems to sound different then if you plug the subwoofer. Not sure what causing it but thinking maybe the output jack got jammed or something so was wondering if anyone knows if it uses a special jack for the output or if i can just get a regular stereo 1/8" output jack and solder it onto the board?