[AUDIO] HDMI 1.3a or Optical?

[Leceur]

Ok my Onkyo receiver supports both HDMI 1.3a and Optical audio. What is better or is there no difference? The only upside I've come up with that I have 1 less cable to hide behind my setup (and with all those cables back there that can really make a difference )

[sammal]

(01-08-2009 04:02 PM)Leceur Wrote:  Ok my Onkyo receiver supports both HDMI 1.3a and Optical audio. What is better or is there no difference? The only upside I've come up with that I have 1 less cable to hide behind my setup (and with all those cables back there that can really make a difference )

it depends from your audio source quality .
If you want to listen regular audio cds, watch dvd videos with ac3, dts or other digitally encoded multichannel audio streams then optical cable (S/PDIF) is good enough.
In technical way the S/PDIF standard supports the following sampling rates:
* 44.1kHz from a CD
* 48 kHz from a DAT tape
* 32 kHz from DSR

if you have audio with higher sampling rates (like dvd-audio or audio from blu ray disc) and you dont want to loose in source quality then you should transfer audio over hdmi cable.
In the real world, ofcourse, you will need also suitable player, good amplifier with suitable DAC and good speaker system to feel the difference

As i understand, currently pch is not very good in playing high quality multichannel audio, yet. But several threads in this forum are giving the hope that maybe one day it will be happened.

[cdx47]

In the realm of films only then standard dvds and anything that is DD or DTS is fine over spdif. High Def audio requires HDMI.

Basically what the previous poster said but shorter

[linuxworks]

(01-09-2009 08:24 PM)sammal Wrote:  it depends from your audio source quality .
If you want to listen regular audio cds, watch dvd videos with ac3, dts or other digitally encoded multichannel audio streams then optical cable (S/PDIF) is good enough.
In technical way the S/PDIF standard supports the following sampling rates:
* 44.1kHz from a CD
* 48 kHz from a DAT tape
* 32 kHz from DSR

you can also run 96k over copper spdif (but not optical). I've recently played around wtih 24bit 96k digital audio and that works ok over coax-spdif. the wire format does support that.

the only time you 'need' hdmi audio is for the vendor lock-in formats that are dripping with DRM ;( the 'true hd' stuff is pure marketing. stick with regular spdif over copper or fiber. 'lossy' 5.1 is still better than your home stereo is (seriously). going lossless is overkill and accepting hdmi audio is not worth it given that home receivers can't resolve better than existing lossy formats.

[BigLarry]

I'm too jealous to reply.

What onkyo is it?

[Derrick]

(01-09-2009 09:39 PM)linuxworks Wrote:  you can also run 96k over copper spdif (but not optical).

Why would that be? The only difference is the transmitter

[linuxworks]

(01-09-2009 10:52 PM)Derrick Wrote:  Why would that be? The only difference is the transmitter

that's the point. as I understand it, there is not enough bandwidth in the WHOLE toslink chain: fiber, tx and rx. they are all designed for the lower frequency spdif signal, not the 96k version which is clock at a higher frequency.

I don't think toslink officially supports 96k, does it?

update: 96k is very iffy for toslink but there ARE some reports of it working. it seems on the edge of what cheap consumer fiber and the toslink modules can do but there ARE some reports of it working.

192k simply won't work on toslink and no one seems to be saying they have it working.

I still suggest coax for 96k and up.

[jofa]

96 kHz 24 bit stereo works very well over optical SPDIF. Both from my NMT, a HDX-1000, and my Tvix-5000, both connected to my Marantz SR7001.
Find some samples here:
http://www.itrax.com/Pages/HelpFAQs.php#1

/J

[linuxworks]

(01-10-2009 12:16 PM)jofa Wrote:  96 kHz 24 bit stereo works very well over optical SPDIF. Both from my NMT, a HDX-1000, and my Tvix-5000, both connected to my Marantz SR7001.
Find some samples here:
http://www.itrax.com/Pages/HelpFAQs.php#1

/J

what kind of toslink cable are you using? how long is it?

have you tried longer ones? just curious.

great that 96k is working for you. I forget which piece of gear I was looking at but they 'stopped' toslink at 48k and insisted the user go with coax for 96k and above.

I also wonder how much jitter rejection you can get when using toslink at such high speeds. some people are worried about jitter at 'only' 48k clock rates

[Leceur]

(01-09-2009 09:42 PM)BigLarry Wrote:  I'm too jealous to reply.

What onkyo is it?

Onkyo TX-SR605:

I'll just leave it on HDMI as that works fine and passes on all audio

[vis-tec]

i would just use hdmi, cuts down on cables, great machine the 605, i have the 606 and its the same but i have 4 hdmi inputs

[SirNickity]

I haven't yet had two devices in the same room that both understood 24/96 SPDIF, but for what it's worth SPDIF optical and ADAT use the same interface hardware. With the ADAT protocol at least, you can send 8 channels of 24-bit 48kHz, or 4 channels of 24-bit 96kHz over one fiber cable. 1.1MBps required bandwidth for that. I just use regular old off-the-shelf SPDIF optical cables, usually decent quality ones at or less than 6' length.