EAX is environmental sound, cannot exactly be described as 3D sound. It sure doesnt have the capabilities A3D has, but it has its own advantages. In games that supports A3D you'll notice the difference(only if you have a very nice 4 speaker set), in games support EAX, you probably wont hear that much of a difference. If you're worried about future support, or if you're going to use Win2K, the Live! is probably your only bet.