Well, i wish i had a fancy soundcard, cause then it would be easy to solve it, but I don't.

I can't rely on things like MPC either, cause this is most often a problem in games. I need something that intercepts all audio on some deeper level. Like a virtual sound driver or something. And whole channels is ew. I don't want monophonic audio. Btw, mapping each channel to 50% would be just the same as mono too :p.