Dolby Digital Plus

Discussion in 'Apple TV and Home Theater' started by StevieT8848, Nov 7, 2015.

  1. StevieT8848 macrumors newbie

    Joined:
    Nov 7, 2015
    #1
    Hey everybody...im new to the forum. I have a quick question. I love the new ATV4 but I have one issue. When i play netflix on my apple tv through my av receiver, it shows Dolby Digital on my receiver. When i play the same movie through my roku 3, it shows Dolby Digital Plus? I cant tell any difference in sound but i thought the AVT4 supported DD+? Thanks for your help.
     
  2. purpleparrotuk, Dec 2, 2015
    Last edited by a moderator: Dec 2, 2015

    purpleparrotuk macrumors 6502

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    Jun 26, 2010
    #2
    One of the main reasons I swapped from the ATV3 to 5 is the fact that is was advertised as producing DD+ Audio (great I thought for Netflix). I currently use my PS3 or Chromecast to get DD+.

    Because the audio settings only have an option for Auto or Dolby Digital I assume the plus has not been implemented?

    Doesnt look like it supports DD+ even though it was supposed to. My chromecast and PS3 DD+ netflix films sound way better than the ATV4 in just DD, I know there should not be much difference but to me its like night and day. So I am still using my other devices to watch Netflix at the moment which I am a bit peeved about.
     
  3. CaTOAGU macrumors 6502

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    Jul 15, 2008
    Location:
    Manchester, UK
    #3
    Yes it can, the sound has to be set to Auto in audio/video settings. In that case the ATV4 will decode the DD+ stream itself and send the result as 7.1 multi channel PCM. It also needs to be plugged in directly to a receiver to do this. Some people have their ATV4's connected directly to a TV and are sending the audio via the Audio Return Channel (ARC). The ARC can not handle Multi Channel PCM, it will only handle up to Dolby Digital 5.1

    The only trouble I have is that PCM output levels seem quite low, this may make other sources like a Chromecast sound subjectively better, as the human ear can interpret louder sounds as better ones. I don't have a Chromecast in order to test this however.
     
  4. loekf macrumors 6502

    loekf

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    Mar 23, 2015
    Location:
    Nijmegen, The Netherlands
    #4
    Silly design decision, so it can only bitstream 5.1 DD (or DTS) and 5.1/7.1 PCM, but not DD+ ?

    Maybe it's a hardware limitation. DD+ can be a far high bitrate, up to 1500 Mbps. However, I have seen passthrough (bitstreaming) to work for DTS up to 1536 Mbps with the MrMC (Kodi) beta.

    Silly design decision @ Apple...
     
  5. purpleparrotuk macrumors 6502

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    Jun 26, 2010
    #5
    But the apple TV is supposed to send DD plus as DD plus to the amp not pcm. The amp needs to see it as this but the apple tv isn't sending it. So it's not working as it should be.
     
  6. Mac... nificent macrumors 6502

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    Nov 20, 2012
    #6
    You know what they say about assuming.

    :apple:TV4 supports the following;

    HE-AAC (V1), AAC (16 to 320 Kbps), protected AAC (from iTunes Store), MP3 (16 to 320 Kbps), MP3 VBR, Audible (formats 2, 3, and 4), Apple Lossless, AIFF, and WAV; Dolby Digital 5.1 and Dolby Digital Plus 7.1.
     
  7. purpleparrotuk macrumors 6502

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    Jun 26, 2010
    #7
    It is supposed to support it, that is the in the specs that you have listed. But it sends it as pcm to the amp. Which is wrong
     
  8. purpleparrotuk macrumors 6502

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    Jun 26, 2010
    #8
    You might as well say it supports thx and true HD because it sends them as pcm too.
     
  9. Mac... nificent macrumors 6502

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    Nov 20, 2012
    #9
  10. CaTOAGU macrumors 6502

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    Jul 15, 2008
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    Manchester, UK
    #10
    It's not wrong necessarily, it is annoying though. It's a perfectly valid design decision and it's the only way of doing it if the device needs to mix its own sounds in, which is what I suspect is happening here. The Xbox one also does this and plenty of early blu Ray players couldn't bitstream true hd or dts ma, they would send a multi PCM stream as well. Personally I'd prefer if it did bitstream though.
     
  11. z06gal macrumors 6502

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    Aug 30, 2011
    #11
    I love the Atv 4 UI but the surround sound is terrible. I don't understand why there is no pass through option. I would much rather my receiver handle that than the Atv.
     
  12. purpleparrotuk macrumors 6502

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    Jun 26, 2010
    #12
    It is wrong because the specs say it can handle Dolby digital plus and it can't. False advertising.
     
  13. CaTOAGU macrumors 6502

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    Jul 15, 2008
    Location:
    Manchester, UK
    #13
    The specs are correct, it can handle Dolby digital plus, it just decodes it on onboard rather than bitstreaming it to the receiver to decode, so it's not false advertising. It is frustrating that there's no bitstreaming option though.
     
  14. purpleparrotuk macrumors 6502

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    Jun 26, 2010
    #14
    Then the specs aren't correct. It should send it to the receiver as is it not decode it on board. Otherwise it is giving us nothing different to what the apple TV 3 does. Especially if you only have 5 speakers anyway.
     

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