HDMI out vs. Optical out

[toneystone]

For audio purposes, will HDMI out sound better than optical out on my HD satellite receiver to my audio receiver?

[turk690]

Since digital is the great leveler, digital audio out enabled from HDMI should have the exact same bits as that which will appear from optical audio out and so should sound the same.

[happydog500]

Sorry for posting on a old thread, but if someone looks this up, I noticed a HUGE improvement when I went from HDMI to Digital Optical. It took 2 seconds to notice. Not even close. Digital Optical is way better.
I called a friend who grew up in his dads recording studio, to tell him how much better it was, and he told me he did the same thing and found the same thing. Not even close.

Chris.

[sanlyn]

Ditto. And digital coax is even better.

(Hint: don't say "optical" or "HDMI" in font of seasoned audiophiles. They'll politely ignore you).

[johns0]

Digital optical and digital coax are exactly the same sound,hdmi output to a decent hdmi receiver will give you better sound with the proper equipment setup so unless you spent thousands of dollars on equipment optical or coax will be good enough.

Best if a mod put this in a new post since the technology has advanced a lot for audio and the old post isn't relevant.

[redwudz]

Digital coax audio and digital optical audio and HDMI digital audio outputted from the same audio device at the same original quality are the same quality. S/PDIF. At least with every audio card/chipset I have used. If I'm wrong, let me know.

[johns0]

Hdmi quality is higher since it can output better audio due to it's bandwidth which optical and coax are limited.

[redwudz]

Good enough for me. I just assumed the HDMI was the same format as the S/PDIF.

[Brad]

(Hint: don't say "optical" or "HDMI" in font of seasoned audiophiles. They'll politely ignore you).

Don't use the words "double-blind testing" around them either!

[happydog500]

Digital coax audio and digital optical audio and HDMI digital audio outputted from the same audio device at the same original quality are the same quality. S/PDIF. At least with every audio card/chipset I have used. If I'm wrong, let me know.

Not true. I could tell in 2 seconds and so did a friend that digital optical audio is better then HDMI, with the same equipment. Not even close.

[jman98]

Ah yes, the old "Me and my friend think so, therefore it's a fact regardless of what the facts really are" gambit. Well played, sir. Well played.
Perhaps next you could play the classic "Nothing beats vinyl" or "Nothing beats analog" lines.

[usually_quiet]

Assuming the equipment used is set up correctly and the audio data being sent is exactly the same, if HDMI sounds worse than optical digital audio then the most likely the HDMI source and HDMI sink aren't communicating properly. ...but the audio data received may not actually be exactly the same. The audio's source may transmit different data depending on the connection used.

HDMI supports HDCP, as well as 7.1 channel LPCM, Dolby TrueHD and DTS-HD Master Audio. Optical and coaxial digital audio connections don't support HDCP, 7.1 channel LPCM, Dolby TrueHD or DTS-HD Master Audio. Optical or coaxial digital audio is limited to 5.1 audio. If the audio source requires an HDCP protected connection or the signal would consume too much bandwidth, the audio can be downgraded to 2 channels for output over optical or coaxial digital audio.

[davexnet]

Here's an interesting article, the author talks about "jitter" or timing errors in the digital samples.
Apparently, HDMI has much higher jitter, thus more errors potentially affecting the sound:
http://www.madronadigital.com/Library/DigitalAudioJitter.html

[usually_quiet]

Here's an interesting article, the author talks about "jitter" or timing errors in the digital samples.
Apparently, HDMI has much higher jitter, thus more errors potentially affecting the sound:
http://www.madronadigital.com/Library/DigitalAudioJitter.html

At the end of the article the author "punts" the question of whether or not the additional jitter from HDMI is perceptible to human ears since it apparently isn't for most people.

[davexnet]

I agree, I read it myself, however I still thought it worth mentioning the article.
To be fair, it's an understandable conclusion. I think it could be a factor, but whether you hear it may depend on
the rest of the equipment. For example, different receivers may have better DAC error handling capabilities.

If you do a search on "jitter" and "sound quality" you get much the same. It's an undesirable thing,
but the audible effect is harder to predict.

[sanlyn]

True, not for "most people".

Also might be a problem with synergy between different system components. Some components (and some cables) are just cheaply made. That's everything from av i/o circuits to cheap or damaged connectors in wires, etc. I have an old VCR whose s-video output is the pits, while its composite output looks cleaner (the damn thing's s-video output even has dot crawl and the usual composite problems !!). I use it to rewind tapes. Another old VCR has grungy audio output that sounds completely different than my other machines (shrill, weak bass) -- and audio from old VCR's isn't all that great anyway. I have to clean up audio captures from that VCR with Audacity. I use a different digital coax from one CD player than I use for another CD player, both into the same preamp. Both cables sound OK from one CD player to preamp (I can't hear a difference, even with headphones), but one of those cables "reacts" differently with the other CD player. Go figure.

[usually_quiet]

True, not for "most people".

Also might be a problem with synergy between different system components. Some components (and some cables) are just cheaply made. That's everything from av i/o circuits to cheap or damaged connectors in wires, etc. I have an old VCR whose s-video output is the pits, while its composite output looks cleaner (the damn thing's s-video output even has dot crawl and the usual composite problems !!). I use it to rewind tapes. Another old VCR has grungy audio output that sounds completely different than my other machines (shrill, weak bass) -- and audio from old VCR's isn't all that great anyway. I have to clean up audio captures from that VCR with Audacity. I use a different digital coax from one CD player than I use for another CD player, both into the same preamp. Both cables sound OK from one CD player to preamp (I can't hear a difference, even with headphones), but one of those cables "reacts" differently with the other CD player. Go figure.

If some of your other posts on the subject of HDMI are to be believed, then even if everything is expensive or very well made, there is no guarantee it will all work well together. The premium gear you own apparently misbehaved until the "right" HDMI cables were found, while the cheap-ass consumer stuff most of us own works equally well with any HDMI cable as long as the cable was made to spec and isn't obviously defective.

[johns0]

Also when switching to hdmi you have setup your receiver/amp to receive the desired type of audio(DTS-HD Master Audio,Dolby TrueHD and dts 5.1,surround,dd etc...)and you have to setup your blu-ray/dvd player to what type of audio it can output cause if you don't it will use the default output mode for hdmi which is probably just plain 2.0 pcm.

[pandy]

Facts:

- Bandwidth for S/PDIF (optical or coaxial) is limited to around 6 - 9Mbps (i.e. maximum audio bitrate), most typical links are bellow 3.5Mbps (especially optical ones TOSLink family - Toshiba and compatible).

- HDMI have more supported audio types (thanks to higher bitrate) - some audio formats can be sent to AV receiver only trough HDMI - there is no alternative digital interface.

- Jitter is important ONLY when transmission clock is used directly as DAC clock to replay samples i.e. jitter in transmission is passed to DAC which nowadays not happen especially for HDMI where there is ALWAYS buffer (like FIFO) that accumulate some amount of samples (packets/frames) before replaying - HDMI is virtually jitter free for PCM audio and it is physically free for compressed audio, similar case for S/PDIF nowadays, each modern S/PDIF receiver is equipped with some buffer (data incoming asynchronously to outputting data).

HDMI is not worse for audio than any modern serial interface (USB, IEEE1394, PCI-expres etc)


There is no sense to measure HDMI cable jitter and compare this to S/PDIF cable - people performing such measurements and comparison have no clue how HDMI works - jitter shall be measured at the DAC input.

[sanlyn]

<sigh> Another bandwidth = bitrate post, and jitter denial. As they say in economics, it's supposed to work in practice but in practice it sometimes doesn't. BestBuy needs you.

[pandy]

<sigh> Another bandwidth = bitrate post, and jitter denial. As they say in economics, it's supposed to work in practice but in practice it sometimes doesn't. BestBuy needs you.

I'm not denying jitter - i'm trying to explain that jitter of interface will not affect DAC as clock for DAC is not taken from interface but locally generated thus all relevant jitter is related to DAC clock not to interface clock (and only DAC clock jitter counts as this jitter decide about conversion errors) - CD technology was designed in second half of 70's and first half of 80's of the previous century then indeed jitter was present and passed to DAC as there was no buffers between interface input and DAC - today data are buffered and played by different clock - i know that for non technical people it is not easy to understand and they prefer faith than science but sorry facts are different - it is particularly funny to read reports from measurement where people with help of sophisticated equipment proving that they have no clue about circuit topology they just measure...

About bandwidth and bitrate - are you capable to understand this http://www.toshiba.com/taec/components2/Datasheet_Sync/215/4884.pdf datasheet or not? If not then sorry but this is moment where discussion ends as i'm not interest to participate in religious debate.

[El Heggunte]

i know that for non technical people it is not easy to understand and they prefer faith than science...

.... but this is moment where discussion ends as i'm not interest to participate in religious debate.

I think there is no point in acting like a "new atheist" (read: antichristian TROLL).

Just my 2 cents, alright.

[pandy]

i know that for non technical people it is not easy to understand and they prefer faith than science...

.... but this is moment where discussion ends as i'm not interest to participate in religious debate.

I think there is no point in acting like a "new atheist" (read: antichristian TROLL).

Just my 2 cents, alright.

Ok what you will wrote when you read statement like - "bandwidth, bitrate is irrelevant" - such claims are nothing else like kind of religious self declaration and personally i believe that everyone can believe in everything he wants but reasonable people will not discuss about personal believes as this have no sense - i've expressed that bandwidth, bitrate and jitter exist, they can be measured but you need to know how and where they should be measured - without knowledge how circuit (signal path from input to output) is designed there is no sense to measure something something" only to prove that you know how to select particular measurement function on AP - more important is how jitter from interface will affect DAC output than how big is jitter in the interface itself.

You may think about this like on normal paper letters - they appear on your mailbox randomly (jitter way) but you can read them in own speed (local clock) if information in letter describe world with day resolution and you receive mail on regular, each day fashion - then information is not lost at all - even if postman put letter in the mailbox around 1 hr jitter.

I never argued that HDMI have lower jitter than S/PDIF - but i pointed that HDMI work on completely different principle as a interface than S/PDIF - this principle make HDMI virtually jitter free from DAC point of view.

btw
why antichristian? - perhaps antisomethingelse?

[sanlyn]

<sigh> Another bandwidth = bitrate post, and jitter denial. As they say in economics, it's supposed to work in practice but in practice it sometimes doesn't. BestBuy needs you.

I'm not denying jitter - i'm trying to explain that jitter of interface will not affect DAC as clock for DAC is not taken from interface but locally generated thus all relevant jitter is related to DAC clock not to interface clock (and only DAC clock jitter counts as this jitter decide about conversion errors) - CD technology was designed in second half of 70's and first half of 80's of the previous century then indeed jitter was present and passed to DAC as there was no buffers between interface input and DAC - today data are buffered and played by different clock - i know that for non technical people it is not easy to understand and they prefer faith than science but sorry facts are different - it is particularly funny to read reports from measurement where people with help of sophisticated equipment proving that they have no clue about circuit topology they just measure...

About bandwidth and bitrate - are you capable to understand this http://www.toshiba.com/taec/components2/Datasheet_Sync/215/4884.pdf datasheet or not? If not then sorry but this is moment where discussion ends as i'm not interest to participate in religious debate.

Been there. I agree, there is no use debating between science and religion -- especially when science becomes a religion. It's too much like trying to force a religious conversion en masse. It seems that a forced conversion of this magnitude occurred in an ancient Roman province around 33 A.D. ...and look at the hassle that involved.

[pandy]

Been there. I agree, there is no use debating between science and religion -- especially when science becomes a religion. It's too much like trying to force a religious conversion en masse. It seems that a forced conversion of this magnitude occurred in an ancient Roman province around 33 A.D. ...and look at the hassle that involved.

http://en.wikipedia.org/wiki/Credo_quia_absurdum

[El Heggunte]

First of all, apologies for the long delay

btw
why antichristian? - perhaps antisomethingelse?

Because the "sheeple" who have blind faith in pseudo-skeptics like Sagan, Randi, Dawkins, Dennett and etc. seemingly don't know any other religion than Christianism. Also, the preferred/only target of their "activism" is the Christian faith. Just take a look at trolling sites like Yahoo! Answers.

Besides, just like the revolutionary fanaticals from the 18th century, they also believe there exists a conflict between religious faith and scientific activity. Obviously such belief is groundless, not to say *fallacious* (a crystal-clear example of «false dilemma»).

http://en.wikipedia.org/wiki/Credo_quia_absurdum

«
We take the side of science in spite of the patent absurdity of some of its constructs, in spite of its failure to fulfill many of its extravagant promises of health and life, in spite of the tolerance of the scientific community for unsubstantiated just-so stories, because we have a prior commitment, a commitment to materialism.
It is not that the methods and institutions of science somehow compel us to accept a material explanation of the phenomenal world, but, on the contrary, that we are forced by our a priori adherence to material causes to create an apparatus of investigation and a set of concepts that produce material explanations, no matter how counter-intuitive, no matter how mystifying to the uninitiated. Moreover, that materialism is an absolute, for we cannot allow a Divine Foot in the door.
»

^ How good is that? As a proof that working with Science does NOT make anyone automagically become a champion of intellectual honesty, the quote above is very-good indeed.

P.S.: Agnostic greetings ^_~

[sanlyn]

I don't know how this got into specific religious "faith". I think it started with statements about science ("digital" specifically) being mythically faultless, or something like that, and the less-scientifically-faithful saying that they tried a piece of wire that seemed to sound "better" in some respects than another commonly accepted piece of wire. It's a worldwide occurrence, and certainly a subjective judgment, and the difference in perception might have to do with some unknown but perhaps (I said "perhaps") measurable scientific ciriteria where some component or other did not comply strictly with scientific theory or implementation in some way. Science knows that 2.5769 and 2.5769 should equal 5.1538, but if some device makes it equal to 5.2634, then somebody screwed up on the device. If you have so much faith in science as to believe that it can't go wrong after humans have messed around with it, it doesn't negate science. There is often a guy named Murphy afoot.

[sambat]

First time this has happened.

[bendixG15]

Some day, soon perhaps, you guys with the "golden ears" will have old age creep up on you and then everything will sound just great.....

[sanlyn]

.....and I'll save a whole lotta time and $$$.