Everything Dolby Digital?

Discussion in 'TiVo Series3 HDTV DVRs' started by generaltso, Oct 8, 2007.

  1. generaltso

    generaltso Well-Known Member

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    Nov 3, 2003
    Vermont
    For the past year, I've been using my S3 with the Dolby Digital to PCM setting enabled and just the stereo speakers on my TV. I decided it was time to enjoy 5.1 surround with my HD recordings, so I hooked up a receiver and changed the TiVo setting to Dolby Digital.

    I figured that the HD channels would be Dolby Digital, but the SD channels would just be regular stereo. But the receiver says that EVERYTHING coming from the S3 is Dolby Digital (with the exception of the menus). I can't imagine that ALL of my channels are encoded with 5.1 surround channels, so is the TiVo doing its own encoding to 5.1? Is there a way to have it just pass the native audio so that HD channels get sent as 5.1 and SD channels get sent as stereo? Basically, I only want to lose the TiVo sound effects if I'm truly getting 5.1.
     
  2. bkdtv

    bkdtv New Member

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    Jan 9, 2003
    DC Metro Area
    Most digital channels are Dolby Digital 2.0 (i.e. stereo). Most -- but not all -- HD channels are Dolby Digital 5.1.

    Most receivers will display lights or some other indicator to differentiate between DD2.0 and DD5.1. You should enable Prologic IIx mode on your receiver so you can get surround audio on DD2.0 channels.
     
  3. generaltso

    generaltso Well-Known Member

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    Prologic IIx mode is enabled, and it indicates that its in Pro IIx mode when I'm at the TiVo menu or when I'm playing a TiVoCast program. But when I play anything recorded from TV, the receiver says it's in Dolby Digital mode and it indicates that all the surround speakers are active. It doesn't really say if it's 5.1 or 2.0, but I assumed it was 5.1 since all the speakers are active.

    I have another receiver that may have more info. I'll hook that one up and see if I can tell which Dolby Digital version is really being output.

    If I change the S3 output to PCM, but have Prologic IIx enabled on the receiver, will I get all the surround channels without losing the TiVo sound effects? Would that just encode all of the surround channels into a stereo signal?
     
  4. bkdtv

    bkdtv New Member

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    Jan 9, 2003
    DC Metro Area
    No, PCM only outputs two discrete channels, similar to DD2.0. Some surround information can be encoded in those two channels, but it's not comparable to DD5.1.
     
  5. CharlesH

    CharlesH Member

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    Aug 29, 2002
    Sacramento...
    Prologic is something of a hack to extract something reasonable from the two channels that can be sent to the additional speakers. DD5.1 has six discreet streams of audio. HD channels usually use DD5.1, from what I've seen on my A/V unit.
     
  6. generaltso

    generaltso Well-Known Member

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    Nov 3, 2003
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    I hooked up my other receiver, and it confirmed that most of the channels are DD2.0 and the HD channels are DD5.1.

    It's annoying that the receiver that I'm planning to use doesn't differentiate between the two. Whether it's DD2.0 or DD5.1, it just says that it's Dolby Digital and shows all 5 speakers and the subwoofer as active.
     

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