Soundcard vs. DAC
Oct 9, 2011 at 2:09 PM Post #16 of 37
No difference...except for the gaming features I mentioned. In a nutshell, sound card as DSP only, when those DSP features are desired.
 
Did you check if the Xonar could even output Dolby Headphone-processed S/PDIF? Very different card to what I'm using, but the whole point of a setup like this relies on the capability to output processed surround sound for headphones over stereo PCM when gaming, which can just as easily be turned off with a checkbox for music listening. (Not that I can test this if I have no DAC with S/PDIF input...)
 
Balancing EAX-era PC game audio and audiophile-grade output for music is such a tough act...
 
Oct 9, 2011 at 2:37 PM Post #19 of 37
Quote:
Remember that most realtek chips do NOT have digital out and if you use analog out you hardly hear the music over the noise with sensitive headphones.


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Quote:
http://www.realtek.com/products/productsView.aspx?Langid=1&PFid=28&Level=5&Conn=4&ProdID=173
The ALC889 incorporates Realtek proprietary converter technology to achieve 108dB Signal-to-Noise ratio (SNR) playback (DAC) quality and 104dB SNR recording (ADC) quality, and is designed for Windows Vista premium desktop and laptop systems.
...
Support for 16/20/24-bit SPDIF input and output with up to 192kHz sample rate offers easy connection of PCs to consumer electronic products such as digital decoders and speakers. The ALC889 also features secondary SPDIF-OUT output and converter to transport digital audio output to a High Definition Media Interface (HDMI) transmitter.

 
The bias against onboard audio here is really bewildering, and this is coming from someone whose source costs more than most people's entire chains.
 
Oct 9, 2011 at 3:15 PM Post #20 of 37
 
Quote:
Dolby Headphone doesn't work over S/PDIF, but Dolby Pro Logic IIx does.


That's not a good sign. I hope my X-Fi cards don't have the same issue.
 
You'd think that Dolby Pro Logic IIx would be unnecessary if using S/PDIF, though, by which I mean "Why not just use Dolby Digital Live instead?"
 
Quote:
Remember that most realtek chips do NOT have digital out...


That's not the case on the vast majority of desktop motherboards I've seen over the last 8 years. Most of them have both RCA/coaxial and Toslink/optical S/PDIF outputs, and one of the earlier examples I can think of uses the old ALC650, not the newer ALC889A or ALC892.
 
Oct 9, 2011 at 3:44 PM Post #22 of 37
 
Quote:
You get that, too. Pro Logic is an option under Digital Live.


I'm not sure exactly how that would work out.
 
My understanding is that the Pro Logic family of Dolby technologies is to matrix extra surround information into two sound channels, so that it can be output with conventional stereo equipment. A proper receiver that can decode this matrixed surround information can then place the sounds in the right spots.
 
However, I don't see how it can possibly be as good as having discrete channels like AC-3/Dolby Digital. I'd think there would be too much chance of bleed/crossfeed and general signal degradation. Basically, if the system can do Dolby Digital to begin with, there isn't much point in doing Pro Logic since there's no need to compress 6 channels into just 2 and expand them back into 6 when they could keep all 6 discrete from the start.
 
Given the way Dolby Labs pitches Pro Logic IIz on their site, though, I'm not even sure anymore...I really don't like it when companies give very different features similar names. (Creative's just as guilty with "CMSS-3D" potentially referring to three completely different features, depending on speaker setting...two of them kind of overlap, but one's meant for headphones and the other's meant for stereo speakers. The third's simply a stereo upmix to play the same sounds in the rear channels, seemingly like what the original Pro Logic was designed to do.)
 
Oct 9, 2011 at 3:57 PM Post #23 of 37
From my understanding, using brief tests when I first got the card, Pro Logic IIx takes a surround sound signal (or a downmixed stereo signal in the case of Dolby Headphone) and allows fine tuning of the sound source. You can adjust sound to play more or less from the virtual front speakers, increase the width of the center channel, etc. I keep it disabled regardless.
 
Sure would be nice if companies just named their products and settings by what they do. But we live in a society driven by buzz words.
 
Oct 9, 2011 at 8:37 PM Post #24 of 37
Sure would be nice if companies just named their products and settings by what they do. But we live in a society driven by buzz words.


So true.

I can confirm that Titanium HD's optical out will carry CMSS-3D, in case anyone was interested.
 
Oct 14, 2011 at 7:24 PM Post #26 of 37
Quote:
WHAAAAAAAAAAAAAAAAAAAAAAAAAAAT?????????
 
tell me this isnt true.
 
ur telling me if i use spdif to connect from pc to external dac i wont be able to use dolby headphone in foobar? 


You won't be able to use ASUS's Dolby Headphone implementation, which is tied to the headphone jack. The Dolby Headphone plugin in Foobar is completely unrelated.
 
May 24, 2013 at 2:18 PM Post #28 of 37
You seem to be confused here, the answers have been correct but not very clear. As I understand it:
 
  • All PC motherboards have an inbuilt sound card.
  1. The sound card takes digital information, and converts it into analogue audio output (it is therefore a DAC)
  2. Think of the internal sound card (whether PCI, or on the motherboard) as an internal DAC.
 
  • If you are using an external DAC you bypass the sound card.
  1. You are sending digital output, straight from the pc (probably via USB), into the external DAC.
  2. The external DAC then converts this into analogue. 
 
They are two separate systems, which both convert digital information into analogue audio output. If you are using one the other is absolutely unused.
 
Is this an answer to your question?
 
May 25, 2013 at 4:35 AM Post #29 of 37
Holy crap, this is quite the thread bump! Takes me back to the old days before I got a bit more audio experience...didn't have my Titanium HD or SU-DH1 back then!
 
Quote:
You seem to be confused here, the answers have been correct but not very clear. As I understand it:
 
  • All PC motherboards have an inbuilt sound card.
  1. The sound card takes digital information, and converts it into analogue audio output (it is therefore a DAC)
  2. Think of the internal sound card (whether PCI, or on the motherboard) as an internal DAC.
 
  • If you are using an external DAC you bypass the sound card.
  1. You are sending digital output, straight from the pc (probably via USB), into the external DAC.
  2. The external DAC then converts this into analogue. 
 
They are two separate systems, which both convert digital information into analogue audio output. If you are using one the other is absolutely unused.
 
Is this an answer to your question?

 
Actually, I can now say with certainty that sound cards ARE still functional when outputting S/PDIF to an external DAC...it's just that they're merely DSPs (only relevant for PC gaming) and a transport now. I can prove that by comparing my X-Fi cards' analog outputs and S/PDIF outputs running through my SU-DH1.
 
USB DACs are really external sound cards without any extra features, just clean analog output. As such, they're considered an entirely separate audio device from an internal sound card and would be indeed totally bypassing any internal sound cards if set as the default audio device.
 

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