Astro Mixamp VS Turtle Beach DSS

I am going to be getting a pair of Audio Technica every where I've read states that these paired with Dolby Digital 5.1 Surround sound is the best thing ever for FPS gaming.

My question is what is the real difference between these 2 pieces of equipment and why is the Astro Mixamp 70$ more than the Turtle Beach DSS Box and If the turtle beach DSS Box would be more than enough to achieve what I want?

http://www.amazon.com/Force-Channe [...] 199&sr=8-1 (Turtle Beach DSS Box)

http://www.astrogaming.com/mixamp-usb (Astro Mixamp Pro I do not want the wireless one)

http://www.amazon.com/Technica-ATH [...] 293&sr=8-1 (Audio Technica AD700)

So my intention is to pair the AD700's with one of these pieces of equipment to create Virtual 5.1 surround sound and Im wondering which one is going to be the best.

Dont know about the mixamp but I use the DSS unit and love it.My gaming is much more immersive.The only downside is DSS doesnt support DTS.Hope this helps