Possibly a stupid question: I have built a new media PC using the onboard Realtek ALC888 of the mainboard for audio. It's running under Windows XP. It is connected to my receiver via 5.1 analog connections, and the Windows speaker configuration is set to 5.1. The Realtek HD Audio is set as default DirectSound output device.
Now, whenever I play a stereo source via the default DirectSound Device, I get some sort of 5.1 upmix from all 6 speakers instead of just the fronts. But I would prefer to just get the pure, unprocessed stereo from the fronts. As far as I can tell, there are no additional DSound filters involved, so it seems the Realtek driver is doing the upmixing, or possibly some kind of HRTF filtering (I have of course set the "Environment" to "none" in the Realtek sound manager). Is there any way to turn this processing off?