Uriel is bang on the money there. TBH I wouldn't want to use the Grado's for gaming, although they are superb for music. Goldring's would be a much better match with a Xonar. I use some DR150's with a Xonar Essence, which also uses Dolby Headphone, same as the DX, and it's a superb combination. The HD595's are likely to be superior for music, but for gaming, as Uriel said, they are not the best pairing with Dolby Headphone. Sure, they will work, just like the Goldring's will work fine with a Creative X-Fi, but the way the phones are designed, makes the Goldring's more compatible with Dolby Headphone, found on Xonar's, and the HD555/595's are more compatible with CMSS 3D found on X-Fi's.