Any difference in sound via hdmi (video card vs soundcard)

[sonic123]

Hi. I have a HD5870 video card that, as you may know, comes with a HDMI output. It is my understanding that the audio signal via the HDMI, if connected to a HDMI input does not need any internal DAC conversion and that actually the video card that has the HDMI output only acts like a pass through device with no processing at all. If that is true, supposing that I am playing a concert BD from my PC, would I get the EXACT SAME QUALITY in sound if I use the video card HDMI output or if I use a dedicated soundcard HDMI output or even if I decide instead to play the concert BD via my PS3? I mean, is the sound provided by HDMI always the same no matter the device that has it? Thank you!

 

[saaiello]

The sound that is output via the HDMI is the same no matter what device its coming from. It sends a purely digital signal to your amplifier or TV and all the processing of the sound is done externally so it doesn't matter if its your motherboard, soundcard, or video card all the sound processing is done externally.

 

[leon2006]

5870 Supports TRUE HD Audio 24 bit 7.1. Do you know what your Sound Card can do?

 

[twipley]

The sound that is output via the HDMI is the same no matter what device its coming from. It sends a purely digital signal to your receiver and all the processing of the sound is done externally so it doesn't matter if its coming from your motherboard, sound card, or video card.

He could not be more right.

Another thread talks about this too, although as relating to the video-card HDMI audio output: http://hardforum.com/showthread.php?t=1648732

 

[gnomio]

With digital it will depend on the device you connect it other. The Radeons got the same DAC as your avg mobo these days.
With 16bit content any modern DAC will do and there won't be difference unless your one of those audiophiles who spend more time listening for ghosts rather than sort out the wiring on the systems. I mean at 16bit all your DAC need to fill is 96gb.

With 24bit content they will start to add noise to the signal normally. 24x 6 = 144db
Minus that with your DACs value and you will get the noise that will be added. There's more math to zoom in on it but the above is the simplest method to think about it.

If you got a receiver at home connect it up the normally got a couple of good DACs on them

 

[Guest]

No you do not get the original audio by default. Unless you are specifically using bitstreaming in the player, the audio is run through Windows' mixer and may undergo sample rate conversion and other pollution such as sounds from other applications, mouse clicks etc.

Even the PS3 has the same problem unless you enable bitstreaming. The PS3 can also decode (and thus mixes) the original audio to LPCM like a PC instead of bitstreaming if you change the settings.

 

[gamerk316]

When using digital, some OTHER device is going to be responsible for converting the sound back to analog before it is sent to the speakers. At the end of the day, you typically want the device with the best DAC doing this conversion.

In any case, be aware some audio processing will still be done at the driver level, but you shouldn't expect any significant change in audio quality when passing to another device using digital.