Here's how it works with X-Fi.

You set windows audio control panel to 5.1 (Advanced Audio Properties). This is required for some games. Newer games might ignore this settings completely and use whatever settings are in the options. I always have my windows control panel set to 5.1 though (it always works and I've not personally tested otherwise).

Then you need to enable CMSS-3D in X-Fi control panel. Two options are now viable when using headphones.

1) If you set the speaker settings to Headphones in X-Fi, you get perfect 3D emulation, in all 3 dimensions. You can hear sounds from left/right/front/rear/above/below. And not just hear them. The emulation makes the sounds with such tones that you actually can "feel" where the sound is coming from. I have a good and expensive set of 5.1 speakers, and this CMSS-3D headphones on X-Fi does 3D better.
There's a drawback with these settings. The emulation algorithms change the sounds to be so different from originals that they appear boomy and muddy. In fact, these changes often make good expensive headphones sound like a pair of cheap ones, primarily in clearity of the sound.

2) Another possibility is to set X-Fi control panel to 2.1 speakers, while still using headphones. This completely eliminates the muddy sound problem with CMSS-3D headphones mode. The sounds are perfect, as if no CMSS-3D was ever enabled.
There's a drawback to this setting as well. You completely lose the above/below 3D emulation. Sounds are still perfectly emulated in the horizontal plane. You can hear left/right/front/rear, but there's no distiction in elevation.

Another drawback, which can be fixed, is that by default, the speaker positions can only be set at -60 to +60 degrees in the X-Fi control panel (THX console). Obviously, to get correct 3D sound positioning with headphones, the speakers would have to be set at -90 to +90 degrees.
This can be accomplished by hex editing 2 X-Fi configuration files. I usually set the angles at -89 and +89 degrees, as I've had some problems with X-Fi mode changer overwriting to the original limits of -60/+60 in some instances at -90/90.

Even though you lose the 3D emulation in the elevation axis, you still get perfect emulation in the horizontal plane + clear sounds. This is what I use all the time on my X-Fi, and it's wonderful.

I have to make a special note that the X-Fi 3D emulation through headphones is absolutely brilliant. It's far superior to anything I've seen before X-Fi in software emulation (HRTF), older creative cards hardware emulation, and (as I've heard from others) Dolby Headphone.
And I mean FAR SUPERIOR. Like I said before, it's better than the real 5.1 setup.


I only have one question. Has anyone tried both CMSS 3D headphones/2.1 and the comparable technology on the new Asus Xonar cards? How do they compare?