SPDIF out only supports up to 48 kHz sample rate and unknown sampling


#1

I just conducted some basic tests of WD TV HD unit (2nd Gen updated firmware etc.).

I used a generic 24bit/96 kHz stereo wav files and connected SPDIF from one good sound card to a reference sound card (X-Fi Elite Pro). I played back this wav file over spdif from the first sound card and the reference sound card displays the status of the incoming SPDIF signal as expected: 

     “24 bit, Stereo, 96000 Hz”.

Then I used the same 24/96 file on a USB drive connected to the WD TV HD unit and connected the SPDIF from WD unit to the same reference card, with everything else kept fixed. When I played back the 24/96  file via the WD HD unit the reference card displayed:

  " ,  Stereo,  48000 Hz"

This demonstrates that the WD TV HD definitely does NOT support 96 kHz sampling rate at the SPDIF out. Also, the “unknown bit” information indicates that perhaps the SPDIF implementation in WD TV HD is not quite right.

Now I really wonder what the implemented quality of audio is over HDMI for high-resolution audio with WD TV HD! 


#2

It wouldn’t be the first thing they didn’t get ‘quite right’. Look around and you’ll also see that they didn’t get mechanical specs for HDMI and USB quite right either. I’m sure this list could be grown a mile long which all comes together in one lousy user experience.


#3

I wouldn’t quite put it that way ;-)  … i.e my experience hasn’t been lousy. I rather like the product but I just wish it was easier to find out the exact specs. For what it costs, I think it is a great product.


#4

Testing the stereo line-out performance with RMAA shows good audio performance:

Using 24 bit and 48 kHz test audio:

  THD ~ 0.005%  (very good)

  IMD  ~ .03 %  (good)

  Noise Level  ~ -91 dBA (very good)

For some reason the crosstalk between channels isn’t great.

However, I’d say that based on these basic tests, you can get very good audio from the RCA lineouts particularly if you rip to WAV (instead of to MP3) … assuming that you feed into a good power amplifier.