ATV4 Surround Sound Issues

Discussion in 'Apple TV and Home Theater' started by iphonetravel, Oct 30, 2015.

  1. iphonetravel macrumors member

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    #1
    My ATV4 arrived last night, so felt the urge to go and set it up. Seems the ATV4 software is still very buggy which surprises me as I would have felt that really tvOS is still at its very core using iOS and a version of the ATV3 code in the background.

    What I have noticed with my 5.1 setup is that surround sound support is poor. If the surround settings are set to "auto", my amplifier reports that the sound is in multichannel mode. Dolby digital content plays in this mode rather than Dolby Digital, and whilst the sound does sound multichannel, I can't imagine that iTunes nor Netflix would want to pipe 5.1 using 5.1 streams of AAC which as some of you know would be a very inefficient use of bandwidth.

    If I set the ATV4 to "Dolby Surround" rather than "Auto", my Amp will correctly report "Dolby Digital". What is interesting however is that content I know is encoded with Dolby Digital + (e.g. some Netflix content), will only show as Dolby Digital, yet my Fire TV (yes, I do have both) will correctly play the content with the higher encode audio.

    Anyone else out there noticing these oddities? For what it is worth, the AT4 seems very much like a beta product at the moment rather than just an evolution as I was expecting.
     
  2. mjcxp macrumors regular

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    Jul 12, 2008
    #2
    I am having the same problem too in regards to the audio problem. I just left it on Dolby Surround for now. Hopefully apple will quickly release new updates to address these issues. Their own apps are also buggy. Some TV shows that I have purchased are missing artwork and will not play, but will play perfectly fine on my other devices.
     
  3. Knowlton82 macrumors newbie

    Knowlton82

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    Oct 31, 2015
    #3
    I'm having the same problem as well. It's a little annoying that they have released it with some any bugs. Feels like we are back at the first iPhone .
     
  4. pob42 macrumors newbie

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    Sheffield, UK
    #4
    Yes I've noticed it too. I guess when set to 'Auto' the Apple TV is internally decoding the Dolby Digital or Dolby Digital Plus stream and then outputting it as PCM over HDMI - similar to how early BluRay players decoded TrueHD/DTS-HD before bit-streaming of HD codecs was common.
    Slightly annoying as I would prefer to have my high-end Amp carry out the decoding as it gives me more control.

    I tried setting the Apply TV to Dolby Digital and that nearly worked fine. It sent a DD 5.1 stream to the amp for decoding. Unfortunately when I watched a program that was only 2.0 it still sent as a 5.1 DD stream (with just Left and Right active) making it impossible to then apply Pro-Logic decoding.

    Hopefully in the future a software update will fix this and allow the raw bitstream to the output. My Amazon Fire TV Stick does this and it works well. I get Dolby Digital and Dolby Digital Plus streams sent to my amp as appropriate.
     
  5. Grumpyman macrumors regular

    Grumpyman

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    Dec 28, 2013
    #5
    its the same as with ATV3, need to select DD rather than auto. dunno why but when using DD it works as expected. Auto just doesn't seem to pick up the DD stream sometimes.
     
  6. pob42 macrumors newbie

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    #6
    My ATV3 was always okay in Auto mode. I got DD5.1 when available and stereo for everything else allowing proper Pro-Logic decoding if needed.
     
  7. Gueeds macrumors member

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    Jul 29, 2015
    #7
    Multichannel mode just means you are getting 5.1 PCM. Nothing is wrong, you are getting surround sound, just the ATV is deciding the surround signal then sending it to your receiver.

    I actually prefer this on the ATV4 only because if you set it to Dolby it auto converts stereo sound to Dolby Digital and you can't use Pro Logic to "fake" surround sound on 2.0 sound sources like Hulu and Showtime
     
  8. iphonetravel thread starter macrumors member

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    #8
    As with others, I never had a problem with the ATV3 when set to auto. In fact my only concern with the ATV3 was lack of apps and no support for DD+ which allows for higher encodes than normal DD, and therefore better fidelity.

    If anything the Fire TV has been more problematic when it comes to surround sound as with the exception the native Netflix and Amazon players, getting other files to play (e.g. with Plex) is near impossible with full DD, DD+ or DTS despite apparent hardware support.

    That said, Apple seems to have miss-stepped here. Hopefully a software update will come out soon, although some of us will need to call Apple support to have the call logged, otherwise they will never know it, especially since so few people have proper 5.1 systems.
     
  9. nivekr11 macrumors regular

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    #9
    Mine is 5.1 on receiver. My hdmi goes through my tv before reciever.
     
  10. Gueeds macrumors member

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    Jul 29, 2015
    #10
    PCM/Multi Channel is 5.1, the Apple TV is doing the decoding instead of your receiver when you set it to Auto. There is nothing wrong with the ATV. When you set it to Dolby Surround, it sends a Dolby Digital signal through. It's just bitstream vs PCM, same audio, just where is it being decoded.
     
  11. iphonetravel thread starter macrumors member

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    #11
    I actually prefer my amp to do all the heavy lifting - not the ATV. I have far more control, which I don't get if the ATV4 does it instead. Also based on my short experiments I don't completely believe the DD+ support.
     
  12. Gueeds macrumors member

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    Jul 29, 2015
    #12
    If you do great, but the Dolby Digital setting is buggy on the ATV4. It upconverts stereo to DD while still only being 2.0 so I can't use Pro Logic on my receiver to get fake surround from Hulu or Showtime or the rare Netflix stereo source. On auto, it correctly sends the stereo signal so I can extend it out more.
     
  13. CaTOAGU, Oct 31, 2015
    Last edited: Nov 1, 2015

    CaTOAGU macrumors 6502

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    #13
    OK, I've no idea how I did it, possibly unplugging/replugging the HDMI cable combined with a power cycle, but now when I set it to output Dolby Surround in the Audio/Video setting section, it correctly bitstreams Dolby Digital during movies and Stereo during music. Before it would try to play music in Dolby Digital too. I realise that theoretically there shouldn't be much difference between the Apple TV doing the decoding and the receiver but when set too Auto the PCM levels were just to damn low and I'm sure there was a loss of detail with it too.

    [Edit: new information]
    The only issue with using it this way is that, it won't bitstream Dolby Digital Plus (DDP). There are only a very few titles that make use of this though and depending on the bitrate that DDP is using, it might not even give any benefit over regular Dolby Digital.
     
  14. CaTOAGU macrumors 6502

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    #14
    Is the sound set to Auto in the audio/video settings?
     
  15. xsmett macrumors member

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    Nov 1, 2015
    #15
    There must be kind of a bug then. Cause i still dont get it work. Even with ur method :(
     
  16. CaTOAGU, Nov 1, 2015
    Last edited: Nov 1, 2015

    CaTOAGU macrumors 6502

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    #16
    Yeah it's definitely buggy, mine just went back to playing music in Dolby Digital. Cycling the setting put it back right but it doesn't feel reliable to me. Hopefully there'll be a bug fix release soon, it's annoying that it's not correct out of the box though.
     
  17. iphonetravel thread starter macrumors member

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    #17
    I don't have that experience with my amp. If in DD mode it does revert to stereo when playing a track without DD encoded material, so I am then able to get my amp to put in either DD Prologic or DTS Neo sound as appropriate. That said, I have not seen DD+ appear when the ATV is placed in DD forced mode.

    All of this seems like it was rushed.
     
  18. CaTOAGU macrumors 6502

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    #18
    Out of interest is yours connected to your TV first or directly to your receiver?
     
  19. OC513 macrumors 6502

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    NYC
    #19
    I am using a Denon AVR, HDMI from Apple TV4 to Denon and then HDMI from Denon to TV. I can not get it to play anything but stereo. No matter what setting I put it on it plays movies in stereo instead of 5.1. Do I need to use the digital audio out on ATV4 and get that cable into my Denon? I shouldnt but I am not sure. Also should I leave the setting in ATV4 settings for sound to my Apple TV or change it to my AVR? Any help would be greatly appreciated.
     
  20. iphonetravel thread starter macrumors member

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    #20
    The ATV4 is connected directly to the receiver via HDMI.
     
  21. CaTOAGU macrumors 6502

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    #21
    Thanks, it's interesting that yours seems to work correctly. I can sometimes get mine to drop back to regular stereo for the appropriate material but it's extremely unreliable. Very frustrating.
     
  22. CaTOAGU macrumors 6502

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    #22
    I've reported the Dolby/PCM issues I've been having to apple at this address

    http://www.apple.com/feedback/appletv.html

    It'd be great if as many of us as possible could do the same to ensure it gets resolved as soon as possible.
     
  23. Gueeds macrumors member

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    Jul 29, 2015
    #23
    What kind of movies are you trying to play and from what apps?
     
  24. OC513 macrumors 6502

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    #24
    Movies I have ripped into iTunes from DVD's. So I go into the 'Computers" app and go into my Movies section. I have tried many and all are playing as stereo.
     
  25. Gueeds macrumors member

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    Jul 29, 2015
    #25
    I loaded up the Dolby test file encoded in DD through iTunes home share. Worked as expected with each channel producing the right sound and getting 5.1 surround out. Are your files encoded in Dolby Digital/AC3? Is your receiver at least lighting up in Multi Channel In or something to that effect?
     

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