IGN tested audio in Windows Vista and their conclusion is that it sucks:
So imagine your surprise when you fire up one of your favourite games in Vista - say World of Warcraft or Prey - only to find your fancy EAX-endowed soundcard and 5.1 surround speakers are dribbling out flat, unenhanced stereo sound. Then, in a vain attempt to spruce up the audio by enabling EAX, you get a nice taut error message saying EAX is not detected on your hardware. What's going on?
Welcome to the world of Vista audio. And a brave new world it is.
The root of all these problems? Microsoft's Windows team made the bold decision to rewrite the Vista audio stack from the ground up, and in doing so they removed hardware acceleration for DirectSound. That's right. They took hardware support away from the most ubiquitous sound API implemented in games over the past several years.
