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Discussion Starter #1
Hi, Folks!


I just ran across a new sound card at Bluegears , the folks who distribute the XMystique 7.1. Like the XMystique, the new XPlosion DTS does real-time Dolby Digital encoding. However, it also adds real-time 1.5M bps DTS encoding !! There's also a DTS-only card, the X-Raider DTS. I've been trying to chase down the details on the CMI8770 chipset, to verify that this is a true hardware encoder, but haven't yet been able to find good references.


This could be a really interesting find! With a 1.5M bps audio stream, this should significantly outperform the audio quality of Dolby Digital, and allow very high-quality digital transport for all sound, including games and WMVHD!


I can't wait to get my hands on one of these to try it out!


Cheers!

MarkF


P.S. Please accept my apologies if this has already been posted. I did try searching first...
 

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Discussion Starter #2
Howdy!


By the way, for folks who aren't familiar with the XMystique card, these cards are actually very well-designed, with high quality audio circuitry. The main disadvantage to them in the past has been the limitations of Dolby Digital itself for high-quality music playback. With the new DTS encoder, this could be an excellent solution, even for folks who are very picky about their audio!


Have Fun!

MarkF
 

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Discussion Starter #3
Hello!


After digging around, I've found that ZipZoomFly will be selling these, with the X-Raider streeting for ~$75, and the XPlosion for ~$125. As soon as they're in stock, I'll pick one up and will post my test results here.


FYI!

MarkF
 

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Hi, Folks!


It's true - this is a genuine hardware DTS encoder. I just found the relevant link on the C-Media chipset site here.


Very cool.


Have Fun!

MarkF
 

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Quote:
Originally Posted by Mark J. Foster /forum/post/0


As soon as they're in stock, I'll pick one up and will post my test results here.

Thanks for being the guinea pig.


I'm looking forward to hearing your test results.


ProofTech
 

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Mark,


Thanks for posting this. Those cards have tempting prices...



I'm interested in reading your review and testing methods.


What kinds of music/movie soundtracks/concerts do you use for reviewing? Please post your list if you can.


I would be interested in your opinions on a DTS audio CD vs redbook CD->Xmystique encoding.


- Steve O.
 

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Discussion Starter #8
Hi, Folks!


Thanks! I've been using the XMystique for about six months, and have been very happy with it, other than wanting even higher fidelity for music. To be clear, as my header suggests, I'm primarily a videophile, and don't claim to be an audiophile. I've recently picked up a pair of Sennheiser HD600 headphones, though, and they're definitely pushing me in that direction!


I'll certainly try a variety of music - one of my favorite albums with the HD600s thus far is Steely Dan's Gaucho. However, the best testing technique I've found is actually a bit different. About a year ago, I developed a prototype of an advanced software-defined radio receiver that used audio in place of RF for development purposes. As part of that effort, I tested many different sound cards using the excellent RAL (Realtime Analyzer Lite) audio analysis program, while running QPSK-encoded and EFQPSK-encoded data streams through the audio outputs. RAL provides extensive FFT analysis, as well as an oscilloscope for checking signal quality. With this combination, I can directly measure noise floor, and get a much better feel for phase noise performance than with anything else I've tried (on the latter, it's not quantitative, but errors are highly visible).


Beyond that, I'll obviously also listen to movies!



Have Fun!

MarkF
 

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Quote:
Originally Posted by Mark J. Foster /forum/post/0


I've recently picked up a pair of Sennheiser HD600 headphones, though, and they're definitely pushing me in that direction!

You should also consider sealed in-ear headphones, like those from Shure & Etymotic. The HD600s are excellent, too. How are you driving them - with a dedicated headphone amp? I hope it's not directly from the PC...

Quote:
Originally Posted by Mark J. Foster /forum/post/0


As part of that effort, I tested many different sound cards using the excellent RAL (Realtime Analyzer Lite) audio analysis program, while running QPSK-encoded and EFQPSK-encoded data streams through the audio outputs.

Please educate me - what's QPSK/EFQPSK?


Explain to me in layman's terms how you compare the DTS encoding capabilities of the sound card to reference DTS audio source. For example, I'm pretty sure there is a DTS audio CD of Steely Dan's Gaucho (highly recommended, if you already like Aja.) How would you test a track from that album against a standard 2-channel CD encoded to DTS with the card?


p.s. You should try out some high-end pro audio cards (Lynx, RME etc) while you're at it. I'm sure blazar is going to jump in here and knock down that idea



Thanks!


- Steve O.
 

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Discussion Starter #10
Hi, Steve!


I drive the HD600s from my Denon AVR-5700 receiver (though I do use a dedicated headphone amp for portable use).


QPSK is Quadrature Phase Shift Keying, a data format where two bits are sent every symbol time, where one of four signal phases encodes the data. EFQPSK is Enhanced Feher-patented QPSK, a similar format that's designed for higher bandwidth efficiency. The beauty of these formats (particularly EFQPSK) is that they have a unique signal pattern when viewed on an X-Y oscilloscope - unfiltered EFQPSK is a perfect circle on an X-Y scope. Any distortion, phase error, DC offset, or level mismatch is instantly recognizable, even errors which would never be audible on sound material to a mere mortal!



By the way, you're right about my reference being Gaucho - I'd accidentally said Aja above, and corrected it just before you posted. To compare the "live" DTS encoding to the pre-encoded version, I'm afraid that I don't have any test instruments other than my ears!
To perform that test, I'll use the Advanced Audio version of TheaterTek Version 2.2.1 to internally decode the DTS audio, and then I can just switch between the card's 24-bit, 96 KHz analog connections, and the real-time DTS encoding connection over S/PDIF. I'll also try pure DTS-passthrough over S/PDIF for completeness.


I've not used Lynx or RME cards, but I have used M-Audio's sound cards for several years before moving to the XMystique, so that's my standard reference.


Cheers!

MarkF
 

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Discussion Starter #11
Hi, Folks!


Just to give you some idea of what EFQPSK looks like in conventional oscilloscope mode, here's a plot of EFQPSK showing the left and right stereo channels sending a data sequence:




If you look at this on an X-Y scope, it really is a perfect circle! One useful thing about this data format is that the spectrum is quite broad, testing almost all audible frequencies - when you listen to it , it sounds like white noise.


Have Fun!

MarkF
 

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Hey, cool post! I am interested in what you find out. I am currently using an older Nforce2 motherboard because it has built-in MCP-T Nforce audio with Dolby Digital Live encoding. I like the sound quality and compatibility (especially that it is hardware instead of software based). I would be keenly interested in its compatibility with decoders such as the popular ones (nvidia, windvd, etc.). Thanks for digging this up. I may buy one myself for my next upgrade!
 

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Discussion Starter #13
Hi, DenyArt! (what's up with that?
)


Thanks for the kudos! I suspect that you're going to be a very happy camper! From my experience with the XMystique, my guess is that you won't have any compatibility problems whatsoever. As long as the X-Raider and the XPlosion use the same basic technique, what the earlier card did was to digitally receive all the sound channels, and then run them directly into the hardware encoder, without ever entering the analog domain. The beauty of this approach is that it's impossible for the originating program to even know that the hardware encoding is occurring!


I know that you'll want the results with the actual cards, and I'll be happy to provide it, but for what it's worth, I've tested the XMystique with TheaterTek/nVidia, PowerDVD, WinDVD, Windows Media Player, WinAmp, and a variety of games, too. I've never had any compatibility problems at all, thanks to the excellent architectural approach that they chose for the card.


For techies that are still curious about EFQPSK, I posted the source code for a reference transmitter a couple of years ago here .


Cheers!

MarkF
 

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Just curious but what would be the main reason that someone would want the XPlosion over the XRaider ? For a HTPC that connects by stereo analog to a TV and S/PDIF to an AV receiver would their be any difference between the two cards? Also it is good that real-time DTS encoding has come to the PC and I too would be interested to hear how much of an improvement their is between DTS and DD real-time encoding.
 

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Hi, Richard!


Let's see... uhhh, because the XPlosion has a cooler name!
The most obvious benefit of the XPlosion is that it'll be easy to do fast A/B comparisons between Dolby Digital Live and DTS Live encoding. In addition, while I have to base this comparison solely upon the writeup on the BlueGears website, it appears that the XPlosion has higher-quality analog audio circuitry (regulated +8V/-8V power, eight socketed op-amps, etc). Whether this will make a substantial difference to us mere mortals is a great question!


I'm not promising this, but I've been thinking about picking up both cards so that I could provide the most information on just these issues for folks here. I'll let you know how my budget's doing when the time comes!



Have Fun!

MarkF
 

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Discussion Starter #16
Hi, Richard!


If only they'd called the low-end card the "X-Rated"... I think the choice would've been a lot easier!



Have Fun!

MakF
 

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Thanks Mark, and I am rather amazed that a company like BlueGears is currently pushing the PC audio world far more than any of the other sound card companies. For instance not only were they the first company to add Dolby Digital Live to an audio card but now they are the first company to add DTS Connect. Also just curious but how would the XPlosion allow faster A/B comparisons compared to the XRaider?
 

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Discussion Starter #18
Hi, Richard!


Since the XPlosion has both Dolby Digital and DTS, based upon the implementation in the XMystique, changing between Dolby Digital, DTS, or analog outputs should be as easy as clicking a single button in the C-Media control panel applet to switch between them!


By the way, Bluegears is just the U.S. distributor. I'm quite familiar with the company behind the XMystique and XPlosion cards - it's HiTeC, a Korean firm that's done incredibly well in the radio controlled airplanes/helicopters space. They have indeed been aggressive with both technology and pricing, and it looks like they're up to it again here!


Best Regards!

MarkF
 

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So why does the Bluegears site on the Xplosion say: Package content: HDA X-Mystique 7.1 DTS Connect audio card / MPC to MPC(2pin-2pin) CD S/PDIF audio cable / TOSLINK fiber optic digital cable / installation CD / warranty card / owner's manual
 

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FusionRx, the full name is "HDA X-Mystique 7.1 DTS Connect audio card " so I would guess that they upgraded several of the components on the XMystique card. The most noticeable upgrade is that they replaced the C-Media CMI8768 that is used with the XMystique with the newer C-Media CMI8770 that is used on the XRaider and XPlosion. Another difference is that the XRaider can connect to the front headphone jack on a PC, which is mentioned in the XMystique FAQ .
 
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