I have an ASUS P4S8X motherboard and am using the on-board AC-97 sound hardware. I have not had any trouble with it until I recently updated the driver for it (that'll teach me to pay attention to Windows Update). Now I have a few extra control panel applications added to my system, and my "headphones on" listening experience is wrecked.
It's as though there is some "ad hoc" 3D sound emulation going on. If I run an MP3 player with the headphones on, it sounds that I am listening NOT to the MP3, but to the MP3 being played through cheap speakers in a padded room, from the viewpoint of somebody just outside the window. In games, I can hear what's supposed to be ambient noise perfectly, but anything happening in the field of view is muted, or I hear what are supposed to be echoes of it, but not the sound itself.
This is especially bad in first-person shooter games. I can't hear any sounds that the player makes, only echoes off nearby surfaces. Any player speech or user-interface noises are muted or lost entirely. And it sounds as though two paper towel tubes are taped to my head ... I have to turn sideways to something to "hear" it properly. Talk about a clumsily-exaggerated 3D audio effect!
On games that have their own support for 3D audio, the effect is mitigated, but not gone. It's the worst on those games without their own 3D audio support.
The wierd thing is, the sound is nearly perfect (or as good as it was before the driver update) if I'm using the speakers. At one point I had a cable-splitter in-line, with one output going to the speakers, and one to the headphones. The speakers would sound fine, no noticeable 3D "emulation," but what could be heard through the headphones was still craptacular. And since I actually enjoy playing FPS games with headphones on, to catch the full audio experience, and because I have neighbors who DON'T want the full audio experience of my games, playing them with speakers isn't a viable option.
I have tried shutting off everything I can. In the "CMI Audio Config" application in the taskbar, I have shut off every 3D audio emulation setting I can. There's another control-panel addition called "AC3 Filter" which appears to have been developed by Martians, for Martians ... it's entirely impenetrable, even to a hardened PC user like myself.
The only other thing that changed, around the same time, was that I had to buy a new video card, because Battlefield 2 won't run on a GeForce 4 chipset. But could a new video card really be screwing up my sound by forcing some sort of accursed, infernal 3D audio scrambling?
I've tried rolling back the driver, but that hasn't helped, probably because of other items that got installed at the same time. It appears that my only options are to shut off the on-board audio and get another audio card, or to wipe my boot partition and reinstall the OS, thereafter jealously guarding it against all audio software updates.
Here's the rest of my system's vital statistics:
ASUS P4S8X motherboard with P4 @ 2.53 GHz
1 GB of PC-2700 DDR memory
MSI NX6600GT-VTD128 video card (GeForce FX 6600 w/ 128 MB RAM)
Windows XP SP2
using on-board AC-97 audio hooked into 2+1 speaker/subwoofer system and headphones (currently switched with MS GameVoice puck).
I'm using the version 77.72 nVidia driver package, and
the latest audio drivers from the ASUS website.
this is where my witty tagline would go if I could be bothered to come up with one
I'd say get in touch with Asus and download the drivers from their site. Then in the device manager update the sound card drivers with exactly that. Then restart, and when back up check what's listed in the sound properties off the control panel. It should still list your onboard drivers from the various pull-down menus.