I'm not sure I agree. I'd say most people that own the Xonar D2 are going to have a high end speaker system that has its own headphone jack.
Intel E6300/Nouctua NH-9U w/dual 92mm Panaflos
XFX 680i LT
Patriot PC2-6400 2X2GB LL
2 X BFG 8800GTX in SLI
Enermax Revolution 620W PSU
ASUS 24X DVD/Seagate 250GB SATA 2/THermaltake A90/Windows 7 Ultimate 64