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Discussion Starter · #1 ·
My $199 Xbox outputs Dolby Digital 5.1 surround sound, which I can be connected to any surround amp, receiver, or speaker system that has optical digital input and DD5.1 decoding capability, without having to connect six separate analog cables. Why then does no manufacturer make a sound card for the PC that can *encode* (not decode, but encode) DD5.1? All the existing cards, including high-end ones such as Creative Audigy II and M-Audio Revolution claim to have digital outputs, but they are useless as they only handle two channel stereo, not 6 channels for surround!!! I know that the nVidia nForce2 chipset can encode DD5.1 (since it was originally made to be used in the Xbox, before Microsoft switched to Intel’s processor), but I need a sound card, not a new motherboard. I also know that Creative’s cards output two separate digital channels (for a totally of 4 channels) which can be connected using a proprietary cable to certain Creative brand speakers (in my case the FPS2000), but they are useless for connecting to a standard multichannel amp or speaker systems.
 

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What is your proposed use? Games? DVD? If it's just DVD then you can pass it thorugh. If you need 5.1 for games then you're out of luck.


And X-Box uses nvidia sound and video processors with an Intel CPU.
 

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Discussion Starter · #3 ·
Quote:
Originally posted by ianken
What is your proposed use? Games? DVD? If it's just DVD then you can pass it thorugh. If you need 5.1 for games then you're out of luck.
Yes, it is for games. Right now I have to switch between digital output and analog when I play games vs. watch a DVD. And on my other system, where I have Klipsch GMX-D5.1 speakers, I cannot get surround at all because the speakers only take analog stereo!!!

Quote:


And X-Box uses nvidia sound and video processors with an Intel CPU.
Yes, I know, but the nForce2 chipset was designed by nVidia for the Athlon processor (before Microsoft switched to Intel). It is not the same chipset as is in the Xbox (which was designed for the Intel chip).
 

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There is no need for DD encoding, because DirectSound 3D supports as many speakers as you have.


To layer DD on top of DS3D is just adding one more step- you'ld do better just by outputting a direct DS3D signal.
 

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The SoundStorm audio chipset found on the nforce2 (with real-time Dolby Digital encoder) is indeed the same as used in the XBOX.
 

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There are no consumer sound cards that does DD encoding because it's mostly useless, cost more money and degrade sound quality. You don't *NEED* Dolby Digital to get surround sound in games.


"but they are useless for connecting to a standard multichannel amp or speaker systems."


Any good receiver and speaker systems have multichannel analog inputs. True most old don't...but then if you go too old you don't have any DD decoding either anyway. What you would want is something along the line of digital audio over FireWire or something like that.



Still why to xBox does it? Because it requires less connector, easier to setup, don't care about sound quality and it's a good marketing gimmick. Most people are entirely clueless about surround sound so having a Dolby Digital stickers sells.
 

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Discussion Starter · #7 ·
To me, DD5.1 encoding is not a stupid gimmik, it's a very convenient feature. I doubt the sound quality of the explosions in my Xbox games is really suffering that much from DD5.1 encoding. When my friends bring their xboxes to have a LAN party, I'm glad they can all connect using just one optical cable (we had 4 Xboxes here last weekend, 13 players total).


My setup in the living room:


ReplayTV

HD-DirecTV receiver

D-VHS deck

Xbox

All are connected using an optical auto switch (audio authority 1154).

All except my HTPC. For that I have run six wires to the analog input of my receiver to get surround sound in games, and a separate optical cable to get DD5.1 bypass when playing a DVD, and switch the receiver's input when playing games. That's lame, it shouldn't take seven connections and two switches to connect an HTCP to a surround amp. All I want is a sound card with the capabilites of the darn Xbox, so I can play my games and watch my DVDs in surround without the jumble of analog wires. I doubt encoding the game's sound effects in DD5.1 really degrades it so much as to be noticable to me, I'm not playing a record on a $4000 turntable. As for DD5.1 making the card more expensive, well, the margin on soundcards must be the highest of any component in the PC- the graphics chips these days have some 50 million transistors and can do tens of gigaflops, and sell for the same price as a sound card!!! If nVidia can make an entire motherboard chipset including integrated graphics and sound (with DD5.1 encoding) for under $50, I'm not sure why they can't make a sound card for twice that price with just 10% of the capabilities.


Cheers,

Moaz
 

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Quote:
To me, DD5.1 encoding is not a stupid gimmik, it's a very convenient feature.
Didn't say it was stupid either, but is it used for maketing. Look at the Unreal II box for example...it's writen Dolby Digital on it! Where's the DD content in the game??? There isn't because in a game it's not pratical (except for cutscenes but I don't know any games that use this so far).

Quote:
optical cable to get DD5.1 bypass when playing a DVD, and switch the receiver's input when playing games. That's lame, it shouldn't take seven connections and two switches to connect an HTCP to a surround amp
Is it so hard to push one button?


Cost wise the hardware isn't that bad but the license fee you have to pay Dolby for each chip isn't free. nVidia makes only a very slim profit on the nForce chipset. They don't make the motherboard itself nor pay the marketing, stocking, shipping, packaging, technical support for the motherboard. Volume market for motherboards (and the xBox) are also much bigger than soundcards. Like all console Microsoft actually loses money for each xBox that is sold, they make money by selling games.


Why do you think nVidia doesn't built a soundcard with the same capability?


ATI and nVidia don't even make much profit on their high end video card either. They make money with OEM contract, AIB and more mainstream mass market product (read lower end).


Sure using seven connection isn't the most convenient but it does work and it's also a very flexible method. The reason for DD was to cram more data in less space, not use less wiring.
 

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My question is why no 5.1 in Windows 2000? I just spent all this money fixing up my old computer to be my HTPC and now find out I'm gonna have to spend more money to get Win XP just to be able to watch HD movie trailers and T2 HD in 5.1 sound.
 

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Ok,


I just now have my HTPC running too. I even bought a Revo 7.1


How will we be able to have T2 WM9 play in 5.1? (my receiver will then turn it to 7.1 with my matrixed EX set up).


I thought something was wrong with my set up since every WM9 or HD trailer has only been in stereo.


What can I do? I have my Revo going to a Yamaha 100x6 receiver.
 

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Don't know why, I can't get 5.1 in WMP9 with Windows 2000 either. But with PowerDVD it's works perfectly. It should work with WinDVD too but for some reason it sort of crash on my PC.


Wouldn't surprise me if it was "broken" on purpose so that you would have to upgrade to XP. A bit like 192kHz support will never added in Win2k (7.1 too while I'm at it).
 

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Quote:
Originally posted by Gozer
Don't know why, I can't get 5.1 in WMP9 with Windows 2000 either. But with PowerDVD it's works perfectly. It should work with WinDVD too but for some reason it sort of crash on my PC.


Wouldn't surprise me if it was "broken" on purpose so that you would have to upgrade to XP. A bit like 192kHz support will never added in Win2k (7.1 too while I'm at it).
The Windows Media page says 5.1 WMP 9 requires Windows XP
http://www.microsoft.com/windowsXP/w...er/51audio.asp


Are you saying 5.1 sound with a Media Player 9 movie is working in WinDVD? If so I'll have to give that a try on my 2000 machine.


I don't think its right that they would force you to upgrade to XP for 5.1 sound when there is no technical reason that I can see that would require that.
 

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Didn't get it to work with WinDVD, I have a rather limited version. PowerDVD works.


From the Hi Def Trailer thread :
Quote:
Discreet WMA Pro 5.1 only works on XP. The basic OS support for MC audio in XP was far better than in older releases which helped make the implementation robust. We could have probably made it work most of the time in other releases, but we were afraid of all the variations and support calls we would get. So we opted to get a solid solution under XP, and a mix down to stereo for the rest.
There you have it. You'll only get stereo from WMP9 under Win2k no matter what. Unless MS decide to add support somewhere down the line for win2k.
 

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Discussion Starter · #14 ·
Quote:
Originally posted by DaveFi
There is no need for DD encoding, because DirectSound 3D supports as many speakers as you have.


To layer DD on top of DS3D is just adding one more step- you'ld do better just by outputting a direct DS3D signal.
That would work if my receiver/amp had a DS3D digital input, as such I wouldn't care about DD5.1, but as it is, I can only decode and amplify DD5.1 (or DTS) on my receivers/amps.


Essentially here are my choices when it comes to getting game suround sounds our of a sound card (other than nForce2):


1- use six analog connections, one per channel

2- use one PCM digital connection and get only two channels

3- use 2 PCM digital connections and propriatary wiring and speakers to get 4 channels


I would like to have a 4th choice, which currently only exists as part of the nForce2 motherboard chipset (SoundStorm):


4- use one digital connection and get however many channels, encoded using AC-3
 

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How about :


5 - one digital connection sending multiple uncompressed PCM channel. Don't what are the manufacturer waiting for. There's already a standard for doing this over FireWire. It's cheap, easy, fast, perfect sound. I guess that's the problem...


Btw, DS3D is an API not an encoding method.
 

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6- some cards let you do stereo PCM out over their digital connections but still keep the surround and center/sub analog outputs functional. that would reduce your theoretical wire count to 5 including your digital connection (really only 3 since the analogs are paired into the same entity, generally). Of course, this usually leads to needing to switch the digital output between passthrough and analog output. My Philips card does this easily, but I've heard horror stories of others needing a reboot to make the setting change function.


btw, I much agree that if we're going to have receivers do our surround decoding, we should be able to just hook up to firewire and then tell our system's control panel what we want sent over it . . . shouldn't even need a sound card then, just firewire capability and some software.


Kensai
 

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Ok, I think i got it.


For DVDs, use the coax, digital output and run it to a coax input on my receiver. I set software to SPIDF.


Now, for other computer audio, including games and Quicktime trailers, etc, I need to buy six 1/8 to RCA adapters and run them to the following analog inputs on my receiver:



Main L-R

Center

Surround L-R

Subwoofer


Is this correct?


I take it I could then switch between 5.1 and digital on the fly with my Revolution?
 

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Got to give props to the Dolby marketing guys for convincing the world that DD 5.1 is the Holy Grail of audio.


I've lost count of the number of people who are convinced that they need DD 5.1 or they can't use or shouldn't bother using something. Right or wrong, that's been my experience.


PC GAMES:

Nearly all games have the audio compressed in some fashion in order to fit on the physical media (CD, DVD, etc.). This compression varies greatly from a little to lots.


During game play, this audio gets un-crunched into RAM to be played/triggered by the game engine. DirectSound 3D or OpenAL route this playback directly to analog speakers connected to the PC.


However, some people are so concinced that DD 5.1 must be better, that they'll happily buy an nVidia equipped motherboard, take that already once-compressed, once-decompressed audio, mash it up again, this time at 12:1, along with compression of the music soundtrack, shove it down the digital pipe to their receiver, where it all gets decompressed again.


I wouldn't tell someone what to do so if you want to do this, be my guest. As a former audio engineer and award-winning sound designer for games, I can tell you I wouldn't choose this process as an ideal delivery method for my hard work, but hey at least the little light on your receiver will turn on when playing a game. That's gotta be worth something, eh?


Console Games:

Again, audio is compressed to fit on the media. The lack of 5.1 analog outputs requires stereo, Lt-Rt output, or discrete digital compression as talked about in the above example. Sometimes even more so because of the small capacities like in the GameCube. RAM and other resources are limited and often slim once the graphics and engine guys are done with everything, so audio is almost an afterthought. X-Box automatically compresses nearly everything to DD 5.1 to go out the digital out If it sounds good to you, then great! Enjoy it.

even compressed 5.1 is usually more appealing than basic stereo. I have no qualms about using the CSII or PLII deocding in an AV receiver by using two-channel PCM output to an AV Receiver.


Other consolegaming platforms don't use DD 5.1 real-time encoding. They do, however use Pro Logic II encoding. If you decode this with a Circle Surround II or Pro Logic II decoder on your receiver, it will sound great.

I think this experience, even using all PLII equipment is more enjoyable than real time DD 5.1 encoding. I know I'll probably get flamed for that, but frankly I don't care about DD 5.1 all that much.


I would prefer the CSII decoded 6 channel output from the M-Audio Revolution, going to the 6 channel analog input of an AV receiver, over compressing and decompressing discrete audio repeatedly just for the sake of using a digital pipe.


The Bottom Line:

For me, it has always been more important that it sounds great than what technology is used. You can get incredible results with CS encoded or PLII encoded content, and the experience can be as good as discrete for some. For others (most it seems), DD 5.1 is the only way they'll be satisfied, regardless of compression artifacts. We should all be thankful there are so many solutions to choose from today.
 

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That's all fine and good, but what about those of us who have a 5.1 system with a receiver that only accepts dolby or dts input over optical or coax digital?


If we have an HTPC and we want to use it to play media other than DVDs (e.g., the new HD T2 Extreme DVD in WM9 format), what's our solution?


I also wonder which is worse--the conversion to DD or the conversion to analog on a typical PC 5.1 sound card.
 

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 This might be what you are looking for:

Quote:
SAN FRANCISCO (March 13, 2003) -- Dolby Laboratories and Texas Instruments Incorporated (TI) (NYSE:TXN) announced they have jointly sponsored the design and development of a device that allows consumers to easily connect PCs with 1394 connectors to their home theater systems.


The FirewireTM-S/PDIF converter allows Dolby® Digital and PCM audio to be transferred from a network of IEEE 1394 devices (which may include laptops and desktop PCs) to the S/PDIF connection commonly found on today´s home audio equipment. This allows music and gaming enthusiasts to play back popular stereo and multichannel 5.1 computer music files, such as MP3, AAC, and WMA, through their home theater systems from their PCs. A prototype implementation of this design was shown at Texas Instruments´ booth at the Consumer Electronics Show (CES) in January.


The converter, created by Island Digital Media Group, consists of an IEEE 1394 connector at one end and a coaxial S/PDIF connector at the other. It requires no additional wires if power is available from the 1394 cable, though a DC connector is available on the device for an external power supply, if needed. The device runs on a Texas Instruments iceLynx-micro (TSB43CB43A) chip.

...
Tomas
 
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