Why do Laser Discs sound consistently better than their DVD counterparts?????

Discussion in 'Archived Threads 2001-2004' started by Dwayne, Oct 14, 2001.

  1. Dwayne

    Dwayne Supporting Actor

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    In light of the the upcoming release of TPM on DVD, and the early reports of the DVD not using the same mix as LD, I find myself asking the eternal question, "Why do Laser Discs sound consistently better than their DVD counterparts?".
    This seems to be the case with many films released on the two formats. When someone keeps telling you how great a particular soundtrack sounds on LD, and DVD doesn't perform on the same level, it can be quite frustrating.
    If anything, I want to understand why this happens so often. Are there technical reasons why? It was to my understanding the DVD was suppose to be superior in all areas, not just video. I just don't understand why the studios cannot duplicate a great sounding LD soundtrack onto a DVD. Is there a method to this madness?
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  2. Brian Harnish

    Brian Harnish Screenwriter

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    Dwayne- From what I've heard in previous posts, the audio is usually encoded at a lower bitrate than it was on the LD. That way, studios can make more room for extras.
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    My DVD Collection
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  3. Neil S. Bulk

    Neil S. Bulk Screenwriter

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  4. Daniel L

    Daniel L Stunt Coordinator

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    Here's the basic reasons:
    For Pro-Logic, Stereo & Mono material:
    Aside from the early years, LD's used PCM (Pulse Code Modulation) which is a less compressed audio format. Generally, DD just doesn't cut it.
    For LD Dolby Digital 5.1 vs. DVD Dolby Digtal 5.1:
    1. LD's do not use dialog normalization. (This is proabably the case for Phantom Menace.)
    2. LD Dolby Digital tracks never had to compensate pro-logic down mixing, thus forcing the low-end frequencies to be comprimised. Of course, if every studio took the time to include both a 5.1 mix & pro-logic mix, as Dobly Labs advises, you wouldn't have this problem either. (See Heat and numerous other Warner titles that only have DD 5.1.)
    For LD DTS vs. DVD DTS:
    Plain and simple, the studios did not have their own DTS encoding equipment until the DVD market. All DTS LD's were mastered by DTS.
    Daniel L
     
  5. Dwayne

    Dwayne Supporting Actor

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    Thanks, Daniel and all. I have a question though:
     
  6. Michael Reuben

    Michael Reuben Studio Mogul

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  7. Robert George

    Robert George Screenwriter

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    Well, so far, a mixture of truth, half-truth, and error...
    The first point to make is that "better" is a subjective term and can't be quantified. One has to define what "better" is before it can be identified.
    Technical facts associated with AC-3 on both formats...
    True, LD 5.1 tracks were all fixed at 384 kb/s.
    Some DVDs do have 384 DD tracks, but most are 448 kb/s. Warner is the only major label to still use 384. All other majors have been using 448 fo DD 5.1 for over two years. Fox and Paramount have used 448 since their very first discs.
    Dialnorm was used on AC-3 tracks on LD, though very few used it to the degree it is used on DVD (most simply used the default setting, as pointed out by Michael).
    2-channel PCM does not have anything like Dialnorm. Most DVD 5.1 tracks use the default Dialnorm setting of -27dBFS which will itself account for a 4dB overall volume difference between a DD encoding and a PCM track.
    If one is comparing 2-channel PCM to DD 5.1, that is really an "apples & oranges" comparison due to the format differences. A true 5.1 mix will usually have completely different levels in the various channels from a Lt/Rt surround mix.
    Discrete 5.1 and matrixed surround from 2-channel PCM are very different animals and will sound very different. Again, "better" is subjective.
    [Edited last by Robert George on October 14, 2001 at 03:10 PM]
    [Edited last by Robert George on October 14, 2001 at 03:11 PM]
     
  8. RobertR

    RobertR Lead Actor

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  9. Shane Martin

    Shane Martin Producer

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  10. Robert George

    Robert George Screenwriter

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  11. Shane Martin

    Shane Martin Producer

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  12. Dwayne

    Dwayne Supporting Actor

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    I understand that many DVD soundtracks are mix for near-field environments, but why even bother if they already have a great sounding mix on the LD? Just throw an additional 2-Ch mix and be done with it, IMO.
    I still don't understand Lucasfilm's comment stating that the DVD soundtrack is a direct port of the theatrical mix. Again, if so, what was the mix on the LD? Is it possible that the DVD is more faithful to the theatrical soundtrack and the LD is "overcooked"? For some reason, I feel that many here do not think that this is the case. Fine. But why would LF make that comment?
    Also, can someone please tell me if the corrected JP DTS DVD sounds like the LD?
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    -Dwayne
     
  13. Dwayne

    Dwayne Supporting Actor

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    This is taken from the digital bits:
    quote:
    Question: Were there any changes in the soundtrack in the Dolby Surround EX mix for home theater?
    Rick Dean: No, there were not. We were very keen on keeping the original acoustic design of Episode I that was used in the theatre for the home as well.
    [/quote]
    Taken from http://www.thedigitalbits.com/articl...dvd/qanda.html
    So what I gather from this is that with all things being equal (the mix in particular), soundtracks will sound inherently better on LD than they will on DVD. Or it insists that the soundtrack on the LD was overcooked. What gives?
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    -Dwayne
    [Edited last by Dwayne on October 14, 2001 at 05:30 PM]
     
  14. RobertR

    RobertR Lead Actor

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  15. RobertR

    RobertR Lead Actor

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    quote: I still don't understand Lucasfilm's comment stating that the DVD soundtrack is a direct port of the theatrical mix. Again, if so, what was the mix on the LD? Is it possible that the DVD is more faithful to the theatrical soundtrack and the LD is "overcooked"? [/quote]
    The mix on the Japanese LD was done by Pioneer of Japan. The mix on the DVD was done by Lucasfilm itself. Given that fact, it does sound reasonable to think that the DVD is more faithful.
    Of course, one can always say "the hell with faithful. Give me what I like".
     
  16. Shane Martin

    Shane Martin Producer

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  17. Vince Maskeeper

    Vince Maskeeper Producer

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    quote: 1. LD's do not use dialog normalization. (This is proabably the case for Phantom Menace.)[/quote]
    Silly- and false. LD did use Dialog Norm, it's part of the DD spec... but an adjustment of 3db of overall gain won't make that drastic an effect on the fidelity of the disc...
    Besides every LD I've ever seen does have dialog norm of -4!
    quote: 2. LD Dolby Digital tracks never had to compensate pro-logic down mixing, thus forcing the low-end frequencies to be comprimised. Of course, if every studio took the time to include both a 5.1 mix & pro-logic mix, as Dobly Labs advises, you wouldn't have this problem either. (See Heat and numerous other Warner titles that only have DD 5.1.)[/quote]
    Well, only a few studios are doing "downmix compensation". Fox, for one, absolutely does not do this. This is not an explaination that would carry much weight imho. I watched engineers at Fox drop audio direct from Mags into protools and they do no additional mixing... raw theatrical 5.1.
    The thing that hurts this whole issue is the lack of education. Again- as when the Jurassic Park issues came up- I had a problem with them, but not for the same reason the majority had a problem with them.
    Again- this issue has come to the front with me. There is certainly an audible difference- which unfortunately is more than bass level, between LD and DVD.
    Anyone who knows me knows I'm not the type to jump on a bandwagon as far as this stuff goes. I don't buy into the bullshit- and I don't make subjective claims as fact. However, that being said- I have found some very strange issues when comparing DD 5.1 on laser and DD 5.1 on DVD-- and the shocking number of times the LD has come out in favor.
    It is not a bass issue, it is a soundstage issue. It is fidelity issue. It's, for lack of a better word, a depth issue.
    And it seems to happen a bit too consistantly for me to believe it is a fluke. If anything 9 out of 10 DVDs should toast the LD counterparts-- but it seems to be happening the other way around- and I'm curious to know why.
    The only real theory I could imagine would be encoder issues. I don't know what the popular outboard DD encoder was at the time of LD- but it is possible that the industry standard encoder was a better unit THEN than what is currently used. It's a shot in the dark, but the only think I can think of...
    I think it's got to be something in the process of how things are done now.
    It could be that now audio stems are dumped into pro tools for encoding to DD, and I imagine it stays in the digital realm for throughput from protools to the encoder. How was it done before pro tools? Possibly that the A/D stage in protools isn't providing the fidelity the previous process offered? I think the previous processes were offering better fidelity in some stage of the encoding process.
    I'd really love to hear from someone working in high end film production and prep to talk about the processes and how they may have changed over the years. I would imagine the houses preparing masters for AC-3 laser (like Pioneer Japan) are using older equipment, and possibly different prcoesses than the modern DVD production studios are using- and I wonder what those differences are- and if they are having an effect on what I'm hearing.
    Again- please understand that I am a rather critical listener- and a little bit of exra bass will not fool me into preferring one version over another. The are some real differences going on- differences which cause me to prefer the LD versions. And I am at a complete loss to give a real answer as to WHY!
    -Vince
    [Edited last by Vince Maskeeper on October 14, 2001 at 07:36 PM]
     
  18. RobertR

    RobertR Lead Actor

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    Interesting theory, Vince. I can think of a bit of detective work that would be useful in helping to prove or disprove it:
    If I'm not mistaken, aren't there some DD LDs and DD DVDs that were essentially made by the same producer during the same time period? I'm thinking of the period between the time that DVDs came onto the market and the collapse of the U.S. LD market. It's reasonable to think that a given studio wouldn't have used different audio equipment to make each format (ie no "older" equipment was used for LD).
    If such a comparison shows that they sound the same (taking into account obvious level or bass differences), then your theory is supported. If they still sound different, that would tend to disprove your theory.
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  19. Vince Maskeeper

    Vince Maskeeper Producer

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    quote: If such a comparison shows that they sound the same (taking into account obvious level or bass differences), then your theory is supported. If they still sound different, that would tend to disprove your theory.[/quote]
    A-ha... however...
    What I'm wondering is if DD ever had an encoding process that would output a raw RF modulated DD stream for LD? In otherwords, would the strict format needed for DD on LD come at the encoding stage, or done at the mastering stage?
    To put it even another way, is the analog RF signal needed for LD created from the digital bitstream (thus possible that the same bitstream was used for LD and DVD)--- OR is the RF created at the encoder stage- so a specific encoder had to be used for LD (and a different for DVD), and thus the whole encoding process would be completely different.
    If that were the case, you could still have differences between LD and DVD coming from the same hands!
    I know the DD LD of Savig Private Ryan was made at the same time as the DVD, yet the sound on the laser is "better" than the DVD and even gives the DTS DVD a serious challenge. Did they purposefully sabotage the DD DVD to give an edge to the DTS DVD?
    Lots of weird options- I wish I had my own encoding system and there was recordable LD- just so I could encode some things and do some tests of each as a digital carrier and see what happened.
    Anyway- there is something weird going on, and I don't think even the studio people are really aware of it. Something is different, but I can't put my finger on what.
    -Vince
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    [Edited last by Vince Maskeeper on October 14, 2001 at 08:28 PM]
     
  20. Dwayne

    Dwayne Supporting Actor

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