HDMI and HDCD

[percy]

I will just bundle two questions in this post -

Does HDMI have any advantage over typical digital coax/optical connection for audio ? I know it has benefits when it comes to video but I not sure what is there to gain for audio. What's in it for audio ?

Does it make sense to play HDCD on a non-hdcd player and use a digital connection to a receiver that has hdcd decoding ? Since regular CDPs recognize a HDCD disk and do play it, does it actually transmit the actual HDCD digital data to the receiver or a compromised version of it ?

Secondly, this is what I found from the hdcd website faq -

"Every CD player has a digital filter that is an integral part of its sound reproduction electronics. In addition to decoding HDCD recordings, the HDCD decoder chip used in consumer products also contains the HDCD high-precision digital filter that improves the sound quality of all types of digital audio recordings. This means that any A/V receiver, CD player, DVD player, and MiniDisc player equipped with HDCD will produce significantly better sound from your entire collection of CDs, DVDs and MDs."

It's basically saying you should always buy a player or a receiver that has hdcd capability even if you wont be using hdcd. Is this true or just a marketing gimic ?

 

[Eric_R]

Since HDMI sends the clock and 6 (or is it 8) channels of digital separatly it has two advantages.
Less clock jitter problems than SP-DIF and that the reciever does not need to decode the audio.
So new formats and compression standards is not a problem since the source (set top box or DVD etc) takes care of decoding.

 

[percy]

that the reciever does not need to decode the audio.

I am not quite following you. There is no set top box meaning the decoding will happen in the player ? What if I dont want to use the player's dac and use the receiver's dac instead for music ? In that case does hdmi have any benefit.

 

[Eric_R]

I am not quite following you. There is no set top box meaning the decoding will happen in the player ? What if I dont want to use the player's dac and use the receiver's dac instead for music ? In that case does hdmi have any benefit.

Yes that works well. With S/P-DIF you could not do that if your reveiver didn't support the standard. For example mulichannel AAC audio from a player would be decoded to 2ch stereo before tranmitting over S/P-DIF but could stay multichannel over HDMI.

 

[percy]

Hmm..
I realize that spdif would carry only 2-ch but I was really wanting to compare with a digital coax/optical connection that runs from the dvd player to your HT receiver which I believe is already multichannel. Or am I misunderstanding something..?

 

[gmarsh]

Hmm..
I realize that spdif would carry only 2-ch but I was really wanting to compare with a digital coax/optical connection that runs from the dvd player to your HT receiver which I believe is already multichannel. Or am I misunderstanding something..?

SPDIF doesn't natively support multichannel (>2 channel) operation.

In multichannel applications, AC-3, DTS or some other format is used to compress 5 channels into a "non-audio" bitstream, which is then sent over SPDIF.

 

[percy]

Thanks for clearing that up.

compress 5 channels into a "non-audio" bitstream, which is then sent over SPDIF.

Now Eric_R did already suggest that hdmi carries the clock and all channels in the multichannel seperately, so if you have receiver with a good dac it should benefit by using hdmi.

Besides that, does this "compression" compromise the quality ?

Sorry for asking so many questions...and thanks for answering them.