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John Dawson Was Right!

Discussion in 'Arcam Forum' started by gbaby, May 14, 2008.

  1. gbaby

    gbaby Member

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    In the past, John Dawson, CEO for Arcam stated that Arcam has not implemented two channel sound over HDMI due to sonic degradation. Apparently he was right. In a recent issue of the respected audio magazine, "The Perfect Vision", renowned audio guru, Robert Harley, states that when he compared the two channel sound of HDMI vs. digital coaxial, he found that the sound over HDMI was thin, bright and hard with a strange, phasey character in the midrange compaired to digital coaxial. In a separate system using an Arcam AV9, Robert Harley indicates that sound through the Sony ES Blu-ray player he used was "outstanding" from the Sony's analog outs due the the Sony's ES great D/A converters. So, for us Arcam AV9 owners, we would be better off forgetting about two channel sound over HDMI and pursue getting a Blu-ray player with superior D/A converters so we can enjoy the new surround codecs from Blu-ray. :thumbsup:
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  2. cjohnson6

    cjohnson6 Member

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    Humm. Does that mean Arcam won't do building an AV10 with sound via HDMI? ;)
  3. gbaby

    gbaby Member

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    To me it means we should not focus on buying new equipment for audio over HDMI, but rather, focus on a blu-ray with a good D/A converter, and with analog outs for playing back the new surround codecs.
  4. shadow 8

    shadow 8 Member

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    "Renowned guru Robert Harley???":rolleyes: Geez, I can find a lot of better reasons to agree with John other than Harley's subjective opinion.
  5. regent8

    regent8 Member

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    What about R Harley (I don't have any history of his contributions to the world of audio = know nothing, yet)?


    The subject is highly interesting, as there are some (Arcam + some others) which refuse to implement audio over HDMI, out of quality reasons.

    All inventions are not for the best - HDMI is convenient but seems not to be an uncompromising solution
  6. Crustyloafer

    Crustyloafer Active Member

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    It won't stay that way for long I can assure you.
  7. regent8

    regent8 Member

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    Perhaps you have som inside info? Arcam don't refuse it out of any policy issues - if it is a good enough solution, they will include it.

    Geoff Meads Brand Manager for Arcam wrote 2 years ago
    "Next-generation gaming devices are almost certain to use HDMI for their high-definition outputs, and PCs, especially media centre types, will almost certainly follow, meaning HDMI will soon become part of our everyday lives.

    HDMI's audio capabilities are constantly developing and, short-term issues aside, the security and bandwidth it provides are certain to ensure that its use becomes commonplace. In recent years, sound quality within home entertainment systems has often come a poor second to picture size, with large portions of the budget being diverted to the latest projectors and flat panel screens. The fact that so much development effort has taken place to allow very high audio performance over the HDMI interface suggests that this may change, and that customers and studios are demanding more from their audio systems, be it from TV, DVD, video games or even good old music."
  8. Ian_S

    Ian_S Active Member

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    I'm sure Arcam will implement HDMI and process audio over it. However, as I understand it, which may well be wrong, the only way to fix the audio signal over HDMI is to buffer it and regenerate the clock accurately in the receiver. Doesn't sound too difficult until you realise that unless you want the audio lagging the picture (which is bad) then IMO you have to buffer the video as well. One 24-bit audio sample is 3 bytes. One line of 1080p video is at least 6KB, more if deep colour is being transmitted. So buffer costs escalate as does the complexity of doing it.

    The alternatives as I understand it are to separate out the audio and use a dedicated interface such as iLink, DenonLink etc... or if you look at Pioneer's upcoming LX71 Blu-ray player, they have implemented PQLS over HDMI, but for CD only. This buffers the audio in the receiver and then reclocks it. My guess would be they limited it to CD as including video gets too complex. Their solution also requires a Pioneer component at both ends.

    A far better solution would be on that can fix the HDMI audio signal for any incoming source.

    So I think analogue connections with high quality DACs still has a lot of benefits, not least the fact that someone like Arcam can keep the audio decoding totally under their control in one box with no HDMI issues. I just hope any such player they may produce for Blu-ray includes full bass management and also the ability to add audio delays to the processing for analogue output to compensate for video processing time later on in the chain.
  9. gbaby

    gbaby Member

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    I apologize as I forgot that I was posting on UK site and not a USA site. In any event, Robert Harley worked at an American magazine entitled, "Stereophile", which later branched off to another magzine called "Sterophile Guide to Home Theater" where he was editor. He has since left this magazine and now is editor of a hign end audio magazine called "The Absolute Sound." Goggle him and you will find that he is an audio guru.
  10. spl23

    spl23 Active Member

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    Hmmm - "an audio guru"? Just to quote what the editor of "The Audio Critic" says about him:

    "The most influential, and at the same time, least qualified writer on digital audio (among other subjects). He got his job at Stereophile by winning an essay contest, for crying out loud! There seems to be no evidence that anyone asked for his academic/technical credentials. His blunders on the test bench and on the printed page are the laughing stock of degreed engineers and academics; he has been skewered and punctured both in print and face-to-face so many times that he resembles a sieve; but he keeps plowing right ahead with his flawed tests and reviews - and his published and editor let him! He appears to believe every half-baked tweako cliche ever put forth, and in his case I am almost certain he is sincere."

    http://www.theaudiocritic.com/back_issues/The_Audio_Critic_24_r.pdf

    So I wouldn't necessarily cite him as an authority, myself...
  11. ianmacd

    ianmacd Member

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    Does that make him the equivalent of What Hifi over here? ( /me ducks and runs for cover :rolleyes: )
  12. DOBLY

    DOBLY Member

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    Nice one IanMcD !!:D:thumbsup:;) - my thoughts exactly !!
  13. gbaby

    gbaby Member

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    Well, I certainly did not cite Mr. Harley for him to endure this type of mockery. Regardless of the critcs and your opinion, he certainly knows something about audio. In fact, I purchased a pair of Infinity Composition Prelude speakers based upon his recommendation in a Stereophile article, and I found his description in that review to be quite accurate. Also, besides him, I have read others describe the sound of 2 channel music through HDMI as "thin." Lighten up, and be nice rather than so personal and critical. :lesson:
  14. gbaby

    gbaby Member

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    It was funny.:)
  15. shadow 8

    shadow 8 Member

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    Again, just because of the coincidence that you and Harley like the same speaker does not make him an audio guru. Any one who can hear can describe what he hears if he is literate. That you both heard the same thing is not unusual. On the other hand, HDMI transmission of an audio signal raises technical questions which can best be addressed by someone with the appropriate background in design and implementation, such as Mr. Dawson.
    That an HDMI audio output may not sound as good to Harley as a digital input may be explained by any number of reasons, but not necessarily that HDMI is a flawed audio medium.
  16. spl23

    spl23 Active Member

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    So you haven't actually heard the sound of HDMI audio yourself, but you are quite prepared to believe what the audio "gurus" tell you about it anyway? Numerous academics and engineers do not regard Mr Harley as being an authority, or his opinions as being worthy of respect - much to the contrary. Given that you were citing him as an authority on the subject, and that seemed to be the sole evidence for your initial statement, I rather felt that the other side of the argument might be relevant.

    And for what it's worth, what I wrote was a direct quote - it wasn't *me* who was being personal and critical. That said, from what I know of Mr Harley and his publications, the criticism in the quote is justified.
  17. gbaby

    gbaby Member

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    Harley is not the only person I read who stated the problems with two channel audio over HDMI. Most high end audio manufacturers share the same sentiments including John Dawson. In fact, they all describe the same sonic trait of the sound of two channel audio over HDMI.
  18. gbaby

    gbaby Member

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    I will admit, I have not heard two channel audio over HDMI. But, time has taught me that you can trust the opinion of certain people. I happen to trust Robert Harley because I've read his description of certain equipment, and purchased them without hearing it, and was able to enjoy all the sonic traits he described of the equipment. With finite resources and almost no ability to hear and test equipment. I rely on what I consider respected publications. I have followed Robert Harley since his Stereophile days, and purchased my speakers (Infinity Composition Preludes), pre/pro (Arcam AV9), Velodyne HGS-18 sub, my ES Sony SACD player, and other equipment based upon his reviews and they performed as described. Yes, I did rely on Robert Harley's impression of what he heard in 2 channel audio over HDMI as well as John Dawson, who has credibilty by virtue of his status with Arcam. Both describe a degradation in the sound quality with 2 channel audio over HDMI so I am not in a position to keep changing equipment on a whim to challenge what they have already experienced with it. I am relying on their judgment until proven otherwise.
  19. HeweyBoy101

    HeweyBoy101 Member

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    Presumably the same issue applies to multichannel audio over HDMI?
  20. ianmacd

    ianmacd Member

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    The issue seen maybe reduced by using both an arcam source and processor so they can do some funky re clocking/some other magical thing over hdmi.

    We know that the physical medium is not necessarily the problem and could be just the protocol on top of it which could be worked around or enhanced.

    I still am in the camp for a newer version of an audio digital connection (ideally both optical and electrical) to succeed toslink/spdif.

    Ian.
  21. gbaby

    gbaby Member

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    My understanding is that there is no problem with multi-channel sound over HDMI, only 2 channel.
  22. spl23

    spl23 Active Member

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    Oh, *please* think about this! Multichannel audio over HDMI will require at least as high a data rate as 2 channel, and almost certainly will require more. If you can send multichannel audio over HDMI without problems, you will also, by definition, be able to send stereo over HDMI without problems.

    Furthermore, I've been re-reading mr Harley's original claim - "when he compared the two channel sound of HDMI vs. digital coaxial, he found that the sound over HDMI was thin, bright and hard with a strange, phasey character in the midrange compaired to digital coaxial". What does "thin, bright and hard" mean in an audio context? Usually, lacking in bass and mid, and with an over-emphasised treble. HDMI is a *digital* connection, and you cannot have frequency-dependent effects resulting from it. So this claim is almost certainly nonsense. Ditto "a phasey character in the midrange" - again, a frequency-dependent effect, so unlikely in a digital transmission line. All the HDMi cable is doing is sending samples - no cable or transmission medium that is doing this can cause frequency-dependent effects.

    It is possible that the HDMI connection was connected to a different DAC or filter from that used by the coaxial connection, which might result in frequency-dependent effects. Similarly, there may have been a difference in the analogue output path used by the two links. But the effect described by Mr Harley cannot be down to the HDMI transmission itself.
  23. gbaby

    gbaby Member

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    I most certainly understand what Mr. Harley means when he says the sound is thin, bright and hard, and I've got some old Sony equipment as proof. :) Again, Mr. Harley is not the only reviewer I've read who described this sonic traits with the sound of HDMI over 2 channel audio. Perhaps these traits are less apparent in low fi equipment and more audible in high end more revealing components. I don't know. But, I'd hate to dive in in find out he's right. I'll wait until the dust settles.
  24. ianmacd

    ianmacd Member

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    I also wonder if he also read these other reviews and theymay have influenced his description of the effects he is hearing.
  25. gbaby

    gbaby Member

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    This is scenario strains reasoning as Mr. Harley has access to equipment by virtue of his standing in the audio community. But, lets not make this about Robert Harley. Goggle some pre/pros with HDMI 1.3 and you'll read the same comments from other reviewers about the effect of HDMI in 2 channel audio. I see you own the AVR300, and our very own John Dawson fundamentally concurs that there are problems. I have heard your receiver, and it has a very "sweet" sound that I find appealing. You would not want to loose that sonic trait if the sound was over HDMI.
  26. Ian_S

    Ian_S Active Member

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    I'm not going to pretend to completely understand what's written here, or given its vintage whether it's all still completely relevant. I also don't know if the tests were valid, but they seem to indicate that jitter if present at certain levels does affect what we hear by introducing spurious additional frequencies that show up...

    http://www.stereophile.com/reference/1290jitter/

    I'm sure stuff has moved on in terms of how good DACs are since then, but if the basic principle is correct it at least should show why control of jitter is important, and as I understand it, this is where HDMI is not necessarily very good right now.

    I think it would actually require John Dawson, or 'Designer' to perhaps comment on whether that article is correct or not.;)
  27. gbaby

    gbaby Member

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    John Dawson has already commented on the negative effects of jitter in audio played over HDMI. You can play a video of his discussion of this issue by visiting the Arcam home page.
  28. Ian_S

    Ian_S Active Member

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    I know John Dawson has said that HDMI has issues with jitter. What I meant was I don't know if the article is a valid one or not. If it is, then it shows how jitter can affect sound, which would go against spl23's claim that a digital signal can't affect frequencies.
  29. gbaby

    gbaby Member

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    Sorry, you are right. Also, google the topic "audio over HDMI." I did and I read an article by an Arcam engineer from 2005 talking about clock speed and error causing jitter and affecting the sound quality. It seem to initimate that this is only a problem for those manufacuters making high end or audiophile gear, and may be completely inaudible for regular consumer gear which would not be as transparent and musical as high end gear anyway.
  30. Len44

    Len44 Member

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    Agree, should not be so much about Mr. Harley (although I have seen his opinions thoroughly dissed by a variety of folks)... The sad reality is the whole HDMI thing is pretty pathetic -- and decidedly unfriendly to those of us who treasure fine audio. The numerous versions of HDMI already foisted on us would be hilarious if not so outrageous. I mean, when might we expect this thing to settle down? Answer: probably never...easy for gear to go outdated much more quickly. :thumbsdow

    I am confident that Mr. Dawson and ARCAM will, in the near future, devise an elegant and quite workable solution to this issue, including ensuring the sound quality is up to snuff, whether for 2-channel or multi-channel playback. Of course, if Mr. Dawson would care to share his current thinking on all this, I'm quite sure it be welcomed by all.:)

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