surround sound 5.1 cables: 6 RCA vs toslink vs HDMI

Discussion in 'High End Audio' started by willbill, Nov 11, 2007.

  1. willbill

    willbill Guest

    surround sound 5.1 cables: 6 RCA vs toslink vs HDMI

    for DVD movies with half decent DD5.1 and/or DTS5.1
    sound, anybody else notice that their AVR (that has 6 RCA
    inputs for 5.1, as well as a player with 6 RCA outputs)
    sounds better when used with the 6 RCA cables?

    i.e. than 5.1 audio via either a toslink connection
    or an HDMI connection

    for the moment, i'm inclined to not buy either
    of the new hi def movie players (i.e. HD-DVD
    and/or Blu-Ray) unless it has 5.1 via 6 RCA cables

    agreed or disagreed?

    willbill, Nov 11, 2007
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  2. willbill

    ScottW Guest

    I'd suggest that if you're making this kind of comparison
    you might be unaware that the settings for channel
    levels or bass management might not be the same
    in the two configurations and therefore create a sound difference.

    ScottW, Nov 11, 2007
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  3. willbill

    Sonnova Guest

    Sounds to me like what you are saying is that you like the surround-sound
    decoder chip in your DVD player better than you like the one in your AVR
    because that's the only difference. TOSLINK and HDMI carry the un-decoded 5.1
    DIGITAL bit stream from the player to the Dolby/DTS decoder in your receiver,
    where it's processed into analog, while the 6 RCAs carry the already decoded
    ANALOG signal from your DVD player (many of which have surround-sound
    decoders already built-in). So the choice is yours decode the sound in the
    player or decode the sound in the receiver.

    Here's the rub: just because the surround-sound decoder in your DVD player
    seems to be better than the one in your receiver, doesn't necessarily mean
    that the decoder that comes in a Blu-ray or HD-DVD player will continue that
    tradition and there is no way (except by auditioning at home before buying)
    to tell beforehand. In other words, the type of interconnect is NOT what is
    determining the quality of the surround-sound in your system. It's the
    decoder you are using. With the 6 individual RCAs you are decoding the
    surround-sound in the DVD player itself, and with TOSLINK or HDMI, you are
    using your AVR to do the decoding. It is possible for one decoder chip to be
    better sounding than another and that's doubtless what you are experiencing.
    Sonnova, Nov 12, 2007
  4. willbill

    willbill Guest

    yes, i'm well aware of the issues of SPL levels
    when making listening comparisons; and yes the
    AVR's bass management (level adjustment) is also
    different when the sound comes in via toslink
    vs. via the 6 RCA connectors

    willbill, Nov 12, 2007
  5. willbill

    willbill Guest

    my DVD player = $230 OPPO DV-981HD

    my AVR = $800 Denon AVR-2307CI

    if it is due to a decoder quality difference,
    i hardly expected it to favor the OPPO;
    meaning that it raised a couple of other
    possibilities including that the audio data
    transmitted via either toslink or HDMI may
    not be as "good" as that via 6 RCA
    yes, i'm aware of that
    tell me about it!

    i still remember my 1st big, heavy, expensive
    solid state amp, circa 1975

    what a major learning experience/disappointment
    that was. :(

    but since you bring the subject up, and since i'm
    thinking about getting one of the Toshiba HD-A2 players
    (or the still newer HD-A3), and assumming it has 6 RCA
    as well as toslink and HDMI, does it decode/sound ok?

    also, don't get me wrong, the Denon AVR is rather
    good and i don't plan to toss it out
    as far as i'm concerned, it's still an open question,
    and hopefully i get closer to a more informed judgement
    as to what reason(s) the difference is due to

    for the moment, so long as i can set up the unit remotes
    to easily switch to the best sound setup, i'm a happy camper

    willbill, Nov 12, 2007
  6. Do you have bass management and delays and speaker level settings
    on in you player *and* your receiver?

    "As human beings, we understand the world through simile, analogy,
    metaphor, narrative and, sometimes, claymation." - B. Mason
    Steven Sullivan, Nov 13, 2007
  7. again, if you are applying processing to the
    signal in the player for one output, and in the
    AVR for another, then unless the processing is the
    same, the final sound may be different.

    For a fairer test, turn off all processing in
    both (except perhaps for speaker levels, to match
    levels) and compare the two.

    "As human beings, we understand the world through simile, analogy,
    metaphor, narrative and, sometimes, claymation." - B. Mason
    Steven Sullivan, Nov 13, 2007
  8. willbill

    Sonnova Guest

    Let's try again. TOSLINK and HDMI are not carrying audio at all, they are
    carrying the digital bit stream. The RCA's ARE carrying audio. The OPPO has a
    very good reputation for sounding extremely good, so it doesn't surprise me
    that you find the OPPO's decoder to be better than the Denon's.
    I have an HD-A2. I use coaxial digital to connect to my Harman-Kardon
    AVR-7000. This receiver uses Lexicon surround-sound processing - which is why
    I bit the bullet and paid close to $2000 for it and is excellent. I've never
    tried the 6 analog outputs from the player.
    Actually, it's not an open question. You are comparing apples to oranges.
    HDMI/TOSLINK is digital, and the RCAs are analog. You're just moving the
    location of the digital decode for your surround sound. It's that cut-and
    Sonnova, Nov 13, 2007
  9. willbill

    willbill Guest

    processing in the player is the same
    for both listening comparisons

    the primary diff is the decoder used,
    secondarily the audio cables used,
    with a third small diff being the
    subwoffer boost

    willbill, Nov 13, 2007
  10. willbill

    willbill Guest

    audio is audio

    the diffs are the transport mechanism and whether
    the mechanical recorded source is digital or analog;
    the usual starting source (performance) is normally
    analog audio
    yes, the OPPO does have a great reputation

    so yes, the decoder is a very real possibility
    the Toshiba HD-A2, that you have,
    does *not* have 6 analog outputs!

    correct me if i'm wrong. :)

    you might consider doing an a/b of inputting
    surround audio via coax digital (which you apparently
    presently do) vs. toslink optical (also digital)

    odds are that you will find a noticable improvement
    with the toslink optical input. :)
    in my long experience, audio is *never* cut-and-dry

    and i'm confident that i'm not comparing apples to oranges

    willbill, Nov 13, 2007
  11. willbill

    willbill Guest

    i think you're missing the point

    the question was/is: if digital audio
    via toslink and/or HDMI cables is equal
    to that via 6 RCA cables

    my ears tell me that it is not, and
    my hunch is that this is really true
    that it is not

    fwiw, i've pulled down some of the specs
    on HDMI from (.wikipedia.?)
    and maybe this will get me to do a detailed
    look through them. not sure if i've got
    anything from wiki on toslink specs

    willbill, Nov 14, 2007
  12. Unfortunately, that arrangement does not permit you to enjoy any of
    the new lossless CODECs (Dolby TrueHD, dtsHD-MA) which can be output
    only over HDMI (as bitstream or LPCM) or over analog outputs.

    Kalman Rubinson, Nov 14, 2007
  13. willbill

    Sonnova Guest

    It doesn't matter. What you are "wondering" is if the method of transferring
    a digital bit-stream, whether optically or via coaxial (HDMI) a few inches
    (from the laser pickup in the player to the on-board surround-sound
    processor) or several feet from the player to the surround decoder in your
    Denon AVR can make a difference in sound quality. If the length of the signal
    path had any effect on the bit-stream, what does that say about downloading
    music from the internet where the path may be thousands of miles over fiber
    optics and coax (and maybe even twisted pair)? The answer is, of course, NO.
    If all the bits get to the decoder it doesn't matter how long the transfer
    path is. Bits is bits. Whether the decoder is in the player and you are
    routing the six channels of audio to your receiver, or if you are taking the
    digital output from the player to the digital input of your receiver, the
    digital signal is, ostensibly, the same in either case. The only difference
    can be what the two surround decoders do to the decoded audio once it has
    been processed.
    Sonnova, Nov 14, 2007
  14. And the answer is, much depends on the settings
    being applied to each. And the relative performance
    of the DAC and post-DAC stages involved.
    Your reasoning about causes and effects is flawed.

    "As human beings, we understand the world through simile, analogy,
    metaphor, narrative and, sometimes, claymation." - B. Mason
    Steven Sullivan, Nov 14, 2007
  15. willbill

    Sonnova Guest

    and digital is digital, but digital isn't "audio" until it is decoded, nor is
    "audio" digital.
    But the transport mechanism is the same for both sets of outputs.
    It might not, I've never actually looked.
    I've never heard any difference between TOSLINK digital, and Coax digital
    I doubt if there is any difference. In fact, when TOSLINK first appeared,
    many audiophiles found just the opposite to be true. I.E., that TOSLINK
    sounded distinctly inferior to either coax or glass-fiber, and indeed, some
    tests showed that the bandwidth of many early TOSLINK setups was much
    narrower than that of either coax or glass-fiber. However, that difference
    has been long since addressed. The optical transducers on both ends of modern
    TOSLINK connections have been significantly improved.
    Believe me. It CAN'T be anything else.
    Sonnova, Nov 14, 2007
  16. willbill

    Sonnova Guest

    What makes you think that the AVR-7000 does not have 6 discrete audio inputs?
    Sonnova, Nov 14, 2007
  17. willbill

    willbill Guest

    fwiw, i thought that it did but then went
    out to and checked and
    discovered that of the 6 current models
    only the most expensive of each line
    has 6 analog outputs!

    so i can't justify one for it's ability
    to upscale normal DVD movies
    you might actually try connecting sound
    with toslink again with your current AVR

    the main key thing that i listen for
    is that the sound is less flat

    but going back to your HD-A2, do you find the
    surround sound of the HD-DVD movies, that you've
    so far gotten, to be noticeably superior to that
    of ordinary DVD movies?

    to my mind, better surround audio is the one real
    trump card that they can play with hi def movies.
    but so far they don't seem to have done it;
    at least not yet. they certainly have plenty
    of great source material in the vaults

    willbill, Nov 14, 2007
  18. willbill

    Sonnova Guest

    I do use TOSLINK from my HD-A2 to my H-K AVR-7000 and I have tried coaxial.
    No difference.
    Absolutely, but not for the reasons that I suspect that you think. Most DVDs
    are Dolby 5.1 encoded. AFAIK, all HD-DVD releases are DTS. DTS sounds
    superior to Dolby 5.1.
    Cinema sound does not impress me that much. It is highly processed, and on
    older films overdubbed to the hilt. As long as they do a good job on the
    surround effects, and the dialog is good and clear, I'm not that critical.
    Like I said, I do notice that music sounds better from DTS than from Dolby
    5.1, and I suspect that the new lossless compression schemes used by both
    High-Definition DVD camps (Blu-Ray and HD-DVD) are even better. But with
    movies, the main emphasis is visual and most modern films sound better in my
    home theater than they did in the cinema. That's about all I think one can
    expect. A film soundtrack is certainly NOT going to sound like a great
    recording of the NY Philharmonic, and I don't expect it to.
    Sonnova, Nov 15, 2007
  19. Simply because I misread your statement and responded to the first
    mention that you "use coaxial digital to connect to my Harman-Kardon

    OTOH, the HD-A2 lacks 6 discrete audio outputs, afaik.

    Kalman Rubinson, Nov 15, 2007
  20. willbill

    willbill Guest

    typo? every HD-DVD movie, that i've looked at
    the back of, has shown the audio to be DD

    agreed, with the footnote that that's a comment
    on those regular DVD movies that offer both
    5.1 formats
    i guess it impresses me more than you. ;)

    for one thing hi end audio, by itself,
    would never have gotten this amazing
    surround AVR equipment on the market

    and without those AVR units, would we
    have mutichannel SACD audio disks?

    willbill, Nov 15, 2007
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