Originally Posted by lemm
Sending computer audio to process in a separate DSP for virtual headphone surround is why I needed DDL. Like yourself headphone use was what I wanted from the computer and DDL input is needed to process that in my DSP. hdmi vs analog was just an extension of that thought since I had all the equipment to achieve that too for when I'm not using headphones.
Thanks for the links. I thought I read somewhere that CMSS-3D is very different from Dolby Headphone, but if CMSS-3D and Dolby Headphone both work with native 5.1 then I guess I'd be ok with either implementations.
You really want to process headphone audio with a sound card, not some other separate DSP (like a receiver)
Creative Labs (CMSS-3D) and Asus (Dolby Headphone) sound cards can take a 6 or 8-channel digital audio feed and convert it into (modern) Headphone Surround Sound, Headphone Surround Sound is a 2-channel audio signal (can be digital or analog), Creative Labs & Asus can send this Headphone Surround Sound out thru the front speaker/line-out (green) jack, as an analog audio signal or thru S/PDIF (optical or coaxial) as a digital audio signal.
The Philips and other receivers can take in this digital or analog signal and send it to their headphone jack.
You need DDL (or DTS-Connect) only if your are trying to send more then 2-channels of audio thru S/PDIF (optical or coaxial).
In the past if you wanted good headphone surround sound for PC games, game makers would include built in support in the PC game, for Creative's EAX 5.0, that would work with the Creative sound card EAX 5.0 hardware/software. The Creative Recon3D and Z series audio processors do not come with the EAX hardware, that the older (Titanium) cards had. Today a lot more gaming audio is processed using software and the computer's CPU, then with the sound card's audio processor itself.