Can't get surround sound to work on my headphones

[ehyde1029]

I have a pair of Triton AX Pro 5.1 surround headphone that I used to use for gaming on my PS3 and they worked great. I recently ditched the PS3 and built a nice gaming rig. After hooking them up to the PC i noticed I couldn't tell where gunshots or footsteps were coming from. I tried to set up surround in the sound menu and it only shows front left and front right speakers with the surround sound box grayed out. As far as I know all my drivers are up to date. Any Ideas on how to fix this?

My headphone are hooked up to the PC through a optical cable if that makes a difference

 

[ehyde1029]

still can't figure it out if anyone has had the same problem