Games, audio formats, cable types?

grafixmonkey

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Hello,

All discussions of movies and blu-ray aside (because this system will never play a movie, a different system handles that)...


If I want computer games to transmit 5.1-channel audio to a home theater amp (probably from Onkyo) are there pitfalls I need to avoid in terms of the sound card I buy, the cable types I use, given that:

-- HDCP compliance is a non-issue,
-- I have not yet bought the receiver (looking at Onkyo) and can look for one with a specific feature,
-- the goal is 5.1 and 7.1 is a bonus that I don't even have the speakers for yet,
-- I probably can't fit the extra two speakers for 7.1 anyway, and
-- I am satisfied with DTS and do not need to have TrueHD?


When computer games play on, say, an Auzentech X-Fi-based card, will that card encode the game's audio into DTS and deliver 5.1 channel audio if I use (preferably) a two-pin SPDIF connection? Or are sound cards unable to encode DTS live, and only capable of passing an already-encoded DTS stream from a DVD, in which case according to what I'm reading I would end up limited to stereo?


Please keep in mind this system will have no need for HDCP compliance, and will never in its lifetime play a movie. My PS3 does that.
 
Solution
If your soundcard supports DTS Live, then an S/PDIF cable to your receiver should do the trick if DTS encoding is sufficient for you. That will only handle 5.1 though.

scotu

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If your soundcard supports DTS Live, then an S/PDIF cable to your receiver should do the trick if DTS encoding is sufficient for you. That will only handle 5.1 though.
 
Solution

grafixmonkey

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Not going to do 7.1. This is going in a 1-bedroom apartment and there's no good place to put the extra two speakers.

I may do 7.1 in the future but we're talking at least 3 years and by then I'll have to buy the new 11.3 receiver with HDMI 1.7 and telepathic HDCP that knows when you're -thinking- about copying a movie.

Thoughts on the Auzentech X-Fi HomeTheater HD for this purpose?

I would pair it with my existing Geforce GTX 260. I see a potential problem where the Geforce's "empty" audio stream could wreak havoc with an HDMI pass-through card. Does that cause problems?
 

scotu

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The Auzentech X-Fi HomeTheater HD is an excellent card in terms of sound quality. As my receiver predates HDMI, don't have experience with using an HDMI audio card, sorry.

Using HDMI audio, however, means you don't need to use DTS Live and can just run 5.1 24-bit 96kHz PCM audio directly to your receiver and get one of the best quality connections to your receiver possible.
 

grafixmonkey

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Since that Auzentech X-Fi HT HD has an analog out to connect my speakers to, it's probably one of the most ideal solutions.

I'm just worried about the whole situation where the Geforce card puts out its own (incorrect, empty) audio stream. If the HomeTheater HD card is blindly interleaving audio streams within a video stream that it does not attempt to interpret... Does it have a chance of being able to notice and replace the existing bad audio stream? Seems this would require it to read and interpret the HDMI signal in a way I'm assuming the card wouldn't try to / be able to do...

And this is better than analog cables why...... lol
 

astrallite

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Asus HDAV or the ATI 5000 series will both do HDMI audio--8 channel PCM and HD bitstreaming. The ATI video card method will probably be more convenient since you eliminate a pci component which lowers heat output in your computer.
 

grafixmonkey

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The question of the moment is whether the empty audio stream the Geforce puts out will be a problem when the X-Fi HT HD tries to inject its own audio into the HDMI.

I won't worry about it if that happens over separate pins or something, but if it's interleaved with the video stream somehow I'd worry about incompatibility, and I don't know how that stuff works yet.
 

scotu

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Given that that Auzentech card is designed for watching blu ray movies (which requires an hdcp compliant video card), I'm going to assume that it won't be a problem. You'll just have to plug the output of the graphics output into the Auzentech input, then the Auzentech output into your receiver.

p.s. HDMI is better than analog because it keeps the signal digital and thus immune to noise until it gets to your receiver, thus offering the potential of a clearer sound. That and you can get 8 channels over one cable, instead of over 4. Also, if your receiver's DAC is better than your soundcard's you'll get a better analog interpretation of the sound.
 

grafixmonkey

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That is a good point, if it didn't work with NVidia cards that would be quite a problem and I'm sure I would have heard of it by now.

Funny thing is I know a whole bunch of audio engineers who pay extra to work on old end-of-life analog equipment, specifically to get that noise... All I can say is analog doesn't have handshaking issues and version numbers. :)