5.1 surround

Discussion in 'Archived Threads 2001-2004' started by Sacha_C, Jan 20, 2003.

  1. Sacha_C

    Sacha_C Second Unit

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    5.1 audio tracks are really recorded in 6 discrete channels right?

    How to non surround (stereo) systems playback 5.1 sound? Does the DVD player downmix to stereo or is there a seperate stereo track on DVDs?

    Someone keeps telling me 5.1 surround sound is encoded in a stereo signal. When I told him I returned my minisystem for a receiver because I want a digital input to have surround sound, he said I didn't need that since the 5.1 signal is encoded in the stereo signal.

    I'm sure 5.1 cant be encoded in a stereo signal, I think he's confusing Pro Logic and 5.1

    He also says 5.1 audio is only 2 channels at the source and the decoder decodes the extra encoded channels out of the stereo signal, he says the source isn't really 6 channels.
     
  2. Steve Schaffer

    Steve Schaffer Producer

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    Sacha,

    Your friend is confusing 5.1 and Pro Logic, just as you suspect.

    Players can and do downmix 5.1 soundtracks to 2 channel stereo for those who don't have 5.1 capability, you don't have to select a 2 channel soundtrack on the dvd.

    Some dvds have both options because 5.1 and 2 channel Dolby surround (or Pro-Logic) really should be different mixes.
     
  3. Sacha_C

    Sacha_C Second Unit

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    Arghhh! He's really driving me nuts now! He is convinced that nothing is recorded in 6 sperate channels and that you can send 5.1 in a stereo signal.

    I showed him this thread I started on another board:
    http://www4.head-fi.org/forums/showt...threadid=24305

    Now guess what he says?

    "LIke I said who do you trust?
    You cannot trust everything you read on the Internet.
    The informatioin is unregulated.

    Lets just drop the subject."
     
  4. Sacha_C

    Sacha_C Second Unit

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    Oh my f**cking god! now look what he says after I said even sony says I need a digital connection for 5.1:

    "Look at it this way, Retailers will tell you you have to
    have a digital connections. This is how they make money.
    If these 10+ people were convinced by a salesman too then I can say they fall into the same category as you. You have been duped."

    I can't beleive him! Damn it frustrates me!
     
  5. ChrisWiggles

    ChrisWiggles Producer

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    Sacha... it's really quite simple. go to Dolby.com and have him read up there. They are the "makers" of Pro-Logic, Pro-Logic II (both matrixed from stereo) and Dolby Digital (5.1 discrete channels). If he can't trust us, I think he'd trust the people who actually designed and invented these surround systems.

    Here's a quote from Dolby:



    And unless you have a DVD player with an on-board 5.1 decoder, which is quite rare now-adays, yes you DO need a digital connection to your receiver in order to get 5.1. To put it politely, your friend is wrong. No fear though, there are SOOOO many people out there that are totally confused and bewildered by surround sound and all it's many connections and formats and compatibilities. The idiots working at chain electronic stores don't do anything to help the matter either.
     
  6. Sacha_C

    Sacha_C Second Unit

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    Thanks, I emailed him that quote. Obviously now he'll say Dolby 5.1 and Dolby Digital 5.1 are 2 different things.

    There is no such thing as Dolby 5.1 (not digital) right?

    Thanks
     
  7. ChrisWiggles

    ChrisWiggles Producer

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    Well, he may be confusing Pro-logic II as "Dolby 5.1" which it most definitely is not. Dolby 5.1, Dolby Digital are one and the same.

    And also, Dolby Digital in its essence is an encoding format akin to say, MP3. It compresses the audio, and supports UP TO 5.1 discrete channels. Just to point out, Dolby Digital may not always be using all those channels. Old movies, for instance, that were only mixed in stereo, or even mono, may be left like that when put onto a DVD.

    Again, have him read through the info at Dolby.com
     
  8. Sacha_C

    Sacha_C Second Unit

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    Great, now he says "If you think you're right then so be it."

    Then he shows me this document that "discribes how the 5:1 signals bandwidth is compressed into the stereo signal", and all the document says is that DTS 5.1 is compressed so the 6 seperate channels take as little place as 2 channels on a normal CD.
     
  9. ChrisWiggles

    ChrisWiggles Producer

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    Both Dolby and DTS are lossy compression formats that reduce the data, like MP3 for instance. It is still 6 discrete channels. Pro Logic II is not compressed, because it's analog, and it's folded into 2-channel stereo. He's flat wrong, and he won't admit it.
     

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