you know, i never got 3d sound to work properly with nvidias drivers. I needed to go get the raw drivers of who ever makes the sound chipset (cant remember who right now, and im not at home). nvidia drivers simply copied sound into the back speakers. I discovered this when playing doom3 as I wanted the 3d audio to be superbly tuned. Cyrix was it? Unfortunatly they have a butt ugly control panel, and some games like unreal 2k4, while the 3d sound was there, the streamed music simply would not go to the sub woofer channel so it sounded something awfull tinny.