Dolby Digital vs. Pro Logic Sound Levels

Discussion in 'AV Receivers' started by Todd Henry, Jun 6, 2005.

  1. Todd Henry

    Todd Henry Second Unit

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    I have the Pioneer 1014 with 5.1 Infinity surround speakers.

    I have run the Auto MCAAC utility with the Pioneer. However, if I listen to a program with the sound set at -40 dB using the Pro Logic II settings the volume levels are fine. However, with the same volume settings and I switch to a program with a Dolby Digital soundtrack, the sound levels esepecially voices are way to soft out of the center channel.

    Is this a config issue or a fact of the 5.1 sound mix that I need to raise the volume when watching 5.1 programs. Is there a better setting to us for non 5.1 programming?

    Todd
     
  2. John S

    John S Producer

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    Inconsistancy amoung levels is quite common between sources and even content these days, hard to say if that is what is happening or not.

    I do tend to adjust my center and sub per content, I never really think twice about it anymore.

    I played with a 1014 for a couple of weeks, and did not notice anything like thsi going on in particular though others have reported it as well. Very similar to what you are saying here.
     
  3. Rich Malloy

    Rich Malloy Producer

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    John is quite correct that there is no consistency in the mastering of audio tracks on DVDs (or CDs, LPs, cassettes, etc.), with some louder than others, and many mastered far, far too lound, beyond the dynamic range capabilities of the given medium. This abominable practice ran rampant in CD mastering for the last ten years, the so-called "loudness wars" (or the quest to produce the all-time shittiest sounding CD).

    But I don't think that's the exact issue you're talking about. I suspect that what you're discovering is the greater dynamic range of the DD5.1 track (whisper quiet conversations to foundation shaking explosions). The pro-logic track has lesser dynamic range, hence a smaller degree of difference between the volume of a whisper vs. that of a gunshot.

    There are features that address this, sometimes referred to as "midnight modes", as they're primarily intended for late-night watching when volume needs to be controlled for sleeping spouses, children, neighbors, etc. These reduce the dynamic range of the DD-5.1 track (that is, reduces the gap between the loudest and softest sounds).
     
  4. John S

    John S Producer

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    Great point Rich.....

    Keep in mind, that what your are supposed to have with DD/DTS is loud, clear, quiet passeges with blow you out of your seat loud passages, just as if you went to a nice theater to see a movie. [​IMG]
     
  5. Todd Henry

    Todd Henry Second Unit

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    Thanks for the feedback. Just to add some more information, I am watching Comcast Cable. I'm guesing it just how the two listening modes handle the soundtrack.
     
  6. Charlie Campisi

    Charlie Campisi Screenwriter

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    That may be your culprit right there. If your DD material is on the premium movie channels, they are routinely broadcast lower than the other channels. I don't have comcast anymore, and don't know the explanation for it, but even on a SD program in stereo, the premium movies were always broadcast at much lower sound levels than all the other stations. It really made channel surfing a nightmare as the volume would jump all over the place.
     
  7. Rich Malloy

    Rich Malloy Producer

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    Yes, there's a big difference between the volume levels of the HD vs. non-HD channels on my RCN digital cable service (non-HD channels much louder), but it doesn't seem to matter whether the HD channels are being broadcast in DD-5.1 or pro-logic. Generalizing a bit, but for the most part it's still the same volume discrepancy.
     
  8. LanceJ

    LanceJ Producer

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    Every time I have activated DPLII on a system the center channel is much too loud for me. This has happened with every brand of receiver and HTiB I've personally played around with. And this is with all channels set to the same numerical level on the component's display.

    As far as the volume level of HDTV vs. regular television stations vs. premium movies, I'm wondering if the lower level for HD is because this allows for a wider dynamic range for the soundtrack (because the DACs of the TV or receiver only have so much electronic dynamic range themselves), which in turn creates more emotion for whatever you're watching. I.e. this contributes to the realism of the entire audio/visual experience. But I don't have HDTV so I'm just guessing here (but as Charlie mentioned I have also noticed quite a few big movies over the years being lower in level).
     
  9. Rich Malloy

    Rich Malloy Producer

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    To a large extent, I think you're right. The DD-5.1 tracks do seem to top-out at a level commensurate with the non-HD pro-logic channels. But many of the broadcasts on the HD channels are only pro-logic (particularly the upconverted SD material), and these are of a notably lower volume than their non-HD counterparts. For example, if I'm watching "The Simpsons" on Fox-HD or a game on ESPN-HD at a nice volume level and then switch over to the same programming on the Fox/ESPN SD channels, the volume is considerably higher.
     

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