[Chaay]

 
tl;dr: Can I get sound on my Xbox 360 from my sound card, and also get Dolby Headphone (5.1 or virtual 7.1) from the Ear Force DSS/Mixamp? I will be ordering the Xonar DG for use with this.
 
I have a couple questions about the best way to get sound on my Xbox 360. So right now I use an adapter that lets me plug my red/white RCA cables into the 3.5mm line-in jack. I then plug my desktop speakers into the audio output jack and it all works fine. This is using integrated audio.
 
I'm going to be getting the Xonar DG soundcard and will be using headphones primarily from now on. I'd like to get Dolby Headphone on my Xbox 360 and was looking at the Ear Force DSS or Mixamp, but after watching the videos I don't understand how it's possible for my setup to get sound? I am going to assume I have the Mixamp simply to make reading easier, though the DSS will do the same thing.
 
If I understand it right, I connect the optical toslink cable from my Xbox to the Mixamp, then plug the headphones directly into the Mixamp. The RCA (red/white cables) don't seem to be used at all now. So how can I get sound from the PC?
 
I get video from my computer monitor via VGA cable and sound from my PC sound card. The videos show setups for Xbox 360 or PC, but I don't know if it works sort of combined like I have it.
 
Everything involved in my planned Xbox 360 setup would be:
Computer Monitor, Asus Xonar DG sound card (inside the running PC of course), Ear Force DSS/Mixamp, Headphones.
 
I'm wondering if all that is enough to give me sound on my Xbox with Dolby Headphone through my headphones.

 

[darkmess]

I always had to switch out the optical cable and the RCA cables. Annoying, but that's seemingly the only way.