Sitting on an old MSI P35 Neo2 motherboard with integrated sound card ... Realtek ACL888. Windows 7.
For some time (can have been since the installation of windows 7 last spring) a strange phenomenon on some movies on youtube where voices have become murky. They become weak and slightly metallic.
I checked the sound settings and have no strange environment settings, etc.I have plugged the headphones in the back and set them as just headphones. Worked with XP without problems. Now it is just as if it had done some kind of backwards conversion from multichannel to two channels (get very clear on the third film of XCOM in steam where the comments are quiet while the music at the end is very high). When I am in realteks program to arrange speakers etc and Press the right speaker the sound can be heard in both speakers. Same thing with the left. If you pull the balance the sound disappears logical in each headphone. Have updated drivers without much difference. It is as if the left / right front are merged and windows thinks there is a center (which unfortunatly is missing on most headphones :-\). I suppose this could explain the murky phenomenon of voices that are unnaturally quiet / metal etc.. Anybody heard of it? Tested to throw in my old audigy1 but it had apparently been disappointed being in a box gathering dust and have moved on to the next life, unfortunately.
I've been googling for the same error but most seem instead to have problems with 5.1 audio, run different sound in the rear and front panel, etc.. You can put up with it in the most games I play but when you are watching WW2 documentaries on youtube it gets a little frustrating.