Originally Posted by silikone
There is something about CMSS that I dislike. It seems harsh on my ears, and it also appears to normalize the audio, which can be very annoying. While Dolby Headphone colours the sound a lot to sound like a room, it does a really good job of widening the soundstage, which may or may not be a good thing.
I like both over Razer Surround, which I think sounds like crap.
CMSS-3D Headphone tends to emphasize treble and dial down bass a bit. Dolby Headphone does the opposite. That might explain some of it.
While the sound quality degradation is not lost on me, the positioning is what I prioritize, and thus far, the only thing that's even comparable to my ears for pinpoint positioning, enough to give me that "your head's in the game!" sensation, is Aureal A3D on a Vortex-chipset card set to headphone mode. This is, of course, assuming native DS3D/OAL/A3D (API) in particularly old cases.
Not everyone is willing to sacrifice sound quality to that extent for better positioning, however. We need better options than the ones we have now, really.
There are some promising new contenders out there, like RealSpace 3D Audio as Fegefeuer pointed out, but they have to be implemented on a per-game basis.