thick question regarding surround sound on headphones

[darkgen]

As the topic suggests, I'm after some headphones which provide surround sound.

Apparently "Sennheiser HD 555" are one of the best to go for but.. how do you enable surround sound when playing games?

I'm presuming I need to get a card which allows for EAX and then some how get the game/OS to recognise the fact I'm using headphones?

*prepares to be enlightened/ignored for thickness*

Cheers, Paul.

 

[darkgen]

Hmm well OK, thanks for the responses.

I decided to look at the Audigy 2 nx or Creative Xmod External USB Sound Card, since I do not have a spare pci slot ,and then after a little more delving it would seem (on the surface) pointless to bother.
Neither eax or cmss3d work correctly/are fully supported within vista x64. According to various articles etc I've read, a lot of functionality appears to be lost etc.

Oh well, Paul.

EDIt to include "Creative Xmod External USB Sound Card"

 

[darkgen]

OK, so what, if any, is the best USB solution to provide surround sound (CMSS-3d) to games (vista x64).

Does one even exist?

Cheers, Paul.