Nvidia graphics card is limited to 2 channel sound output.
Nothing I've ever heard of - plenty of HT guys run nVidia and ATi cards and stream 7ch. But it would not surprise me to hear that yet another HDMI related feature is broken.
I said "uncompressed LPCM" because I wasnt sure if there was some software method to compress it, transport it, and then decompress it (like winrar on the fly or something).
Yeah, it's called Dolby Digital Live and/or DTS: Connect. But you lose some fidelity in the compression (but it doesn't matter, as I've told you three times now, for videogames or movies, because those are already heavily compressed).
S/PDIF gets you 2 channels, but I cant think of a reason that multiple toslink/coax cables couldnt be used in the way that multiple RCA cables are used to transfer LPCM.
Except that you can't use multiple transports or sync things up that way, and that S/PDIF does not work that way, and that it would have clocking issues. AES and ADAT can do this, but you don't want to know how much that costs. S/PDIF can do up to 7 channels (6.1) with Dolby Digital or DTS (as I've said, three times now).
I guess HDMI does that without requiring multiple cables though, or rather it does that but bundles the cables into a much more manageable package.
HDMI has a substantially (SUBSTANTIALLY) higher bandwidth, as opposed to S/PDIF. So it can carry more data. 8 channels of PCM audio is BIG (there's a reason Blu-ray still uses compression, albeit lossless compression).
Why wont DDL/DTS:C matter? I'd love the elaboration on this. I thought DTS:C is a much higher quality compression method, like the difference between 128kbps MP3 vs 320kbps MP3
Because they're extremely similar in principle and with games you're taking compressed audio in and sending it out, so as long as your "re-compression" isn't narrower than the inlet, it won't kill the fidelity (and in this case, that reigns true for the most part). DTS is not "much higher quality" - both can run right up to 1411kbps, neither live encoding method takes advantage of this though. DTS *technically* would have an edge at extreme HF (where nothing exists) because it doesn't sum, but they're so tight-lipped about what the Connect encoder actually does, it may very well be summing. The point is, it is *not* like the comparison you're making. For stereo music you do not want to use either of these methods, you want to send stereo PCM.
Obviously both would be high enough quality that one wouldnt notice except for on higher end equipment, if at all
Yet another myth.
Also, I recall something about DTS having discrete rear channels while dolby had interpolated rear channels or something like that. I read it a long time ago, I might be confusing it with something else entirely.
Pure fabrication. Dolby and DTS both provide 5.1 discrete, and 6.1 matrix (and DDL/DTS:C cannot do 6.1 EX/ES output, but if your receiver has PLIIx (or z) or Neo:6 it can apply the same matrix). Perhaps you're thinking of Dolby Surround (aka Dolby Pro Logic) which is four channels, and uses a mono, band-passed surround?
All I really NEED from the reciever is pre-amp outputs, and all I really NEED in terms of preamp outputs is front channel, or possibly rear channel preamp outs. The pioneer does this, but its not really a terribly future-smart purchase. It has HDMI audio but as I said, nvidia only supports 2 channel audio over HDMI and my motherboard has no HDMI. It has an S/PDIF header but no S/PDIF port, otherwise I woudlnt even bother with the sound card except for the DTS:C and DDL capabilities when I wanted them in the future.
That Pioneer has no such outputs. S/PDIF ports can be added to headers very cheaply (at least coax ones, it's a simple two pin wire rig - you can buy them premade for a few dollars also), but I doubt your board has DDL (it might, I've seen some newer boards include the license (it's all software)).
If you just need 5.1 analog pre-out, the soundcard (or whatever) can drive that all day. You might not be able to go up to 100% output depending on the Vrms output of the card relative to the sensitivity of your amps, but you won't hurt anything as long as you don't run the amp into clipping (you'll hear this, it's very noticeable).
Right now I'm using a borrowed stereo preamp/stereo power amp. The stereo preamp has pre-outs and i'm using them with a pair of Pioneer HPM-60's paired with Audioengine A5's and Dayton Audio Titanic Mk III subwoofer. Overall, it makes for a great 2.1 combination, (arguably 4.1) but the stereo image is rather lacking, especially given my horrible room acoustics.
That is not 4.1. Not even close. And it also explains the poor stereo image - you're running two of the same speaker = all sorts of nasty interference. What are you using for bass management, also?
The dolby headphone capabilities of this sound card will help with gaming immediately, but the 5.1 capabilities are what i'm really looking forward to. And maybe eventually 7.1 once i'm not college broke.
Dolby Headphone (or CMSS-Headphone via Creative) is indeed a nice feature, and I do agree about it's merits with gaming. Same for proper surround out into your speakers.
Here's roughly what I'd suggest:
Run your soundcard's 5.1 analog out (configured to 4.0/4.1 (nobody does a true 4.1 output)) into your pair of stereo amps or powered speakers or whatever, use the soundcard/PC as the volume control, and hook-up the sub on the front L/R with whatever you're using for bass management. If none of that applies to your situation or can apply to your situation (due to some other unknown variable), go with a modern AV receiver into 4+ speakers and feed it stereo PCM via S/PDIF for music (which is already the tops, you get no benefit from going to HDMI for this one), and DDL into 5.1 for surround sound (and then configure the receiver's output map to match your speaker array, and let the receiver do all bass management and channel leveling, and the computer acts as a source, like a DVD player).
If you need more specific info, feel free to ask.
