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ledzep1
Headliner II
November 16, 2020

Dolby 5.1 content outputting as multichannel PCM 7.1 (since LPCM update)

Hi

Thought I would create this thread as a few have reported this issue in the lpcm update threads that are marked as solved so perhaps best to keep it separate.

Issue:

Before the LPCM update last week my sonos arc would receive atmos and Dolby digital 5.1 from the Apple tv 4k box, audio settings were set to the default AUTO-Atmos available.

My LG CX is capable of passing LPCM.

 

Now since the LPCM update with the above settings I still get atmos from apps such as netflix, apple tv + on the apple 4k box, but any content in dolby 5.1 is now outputting as multichannel PCM 7.1, 7.1 being the issue, it should be outputting as multichannel PCM 5.1

 

I have seen similar posts with this issue on the same device and other devices as well.

 

Thank you 

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    57 replies

    Bilal
    Trending Lyricist I
    November 16, 2020

    No issues here LG B9 and sonos arc with Apple TV output 5.1content as multichannel PCM 5.1

    ledzep1Author
    Headliner II
    November 16, 2020

    Just to update happens on my xbox series x as well, which is set to uncompressed 5.1, and sonos arc outputs as 7.1

    Perhaps its an lg cx issue, I know i’m not the only one with this issue, those that have the problem please state what tv you have.

    jthomas009
    November 16, 2020

    I get the 7.1 if it is set to passthrough.  It changes to 5.1 if I set the tv to auto.   This is on 2020 75 LG Nano 90 and I also just got a 55 LG OLED CX.  It was the same, so I just returned it and just now realized my Nano 90 is doing the same thing.

      ledzep1Author
      Headliner II
      November 16, 2020

      I get the 7.1 if it is set to passthrough.  It changes to 5.1 if I set the tv to auto.   This is on 2020 75 LG Nano 90 and I also just got a 55 LG OLED CX.  It was the same, so I just returned it and just now realized my Nano 90 is doing the same thing.

      Yeah seen a few mention AUTO works on lg cx, but for those that want to pass full fat atmos (true hd) from say a 4k bluray player, it needs to be set as passthrough.

      Certainly a strange issue/bug.

      argonaeut
      Lyricist I
      November 16, 2020

      I also have the 7.1 issue. I just wanted to chime in and say that AUTO does not work to output Multichannel PCM in 5.1 on the LG CX for me. If I do AUTO, then it will only play PCM 2.0.  My settings are HDMI Input Audio Format set to Bitstream and Digital Sound Out set to Pass Through. On my PS5, I have the Audio Format set to Linear PCM. When I play games,  the About My System page in the Sonos app shows Multichannel PCM 7.1. 

        ledzep1Author
        Headliner II
        November 17, 2020

        I also have the 7.1 issue. I just wanted to chime in and say that AUTO does not work to output Multichannel PCM in 5.1 on the LG CX for me. If I do AUTO, then it will only play PCM 2.0.  My settings are HDMI Input Audio Format set to Bitstream and Digital Sound Out set to Pass Through. On my PS5, I have the Audio Format set to Linear PCM. When I play games,  the About My System page in the Sonos app shows Multichannel PCM 7.1. 

        Good to know, hadn't tried Auto on the cx myself, just thought someone had mentioned that works, but perhaps not then.

         

        Briinthesky
        Trending Lyricist III
        November 17, 2020

        Hi

        Thought I would create this thread as a few have reported this issue in the lpcm update threads that are marked as solved so perhaps best to keep it separate.

        Issue:

        Before the LPCM update last week my sonos arc would receive atmos and Dolby digital 5.1 from the Apple tv 4k box, audio settings were set to the default AUTO-Atmos available.

        My LG CX is capable of passing LPCM.

         

        Now since the LPCM update with the above settings I still get atmos from apps such as netflix, apple tv + on the apple 4k box, but any content in dolby 5.1 is now outputting as multichannel PCM 7.1, 7.1 being the issue, it should be outputting as multichannel PCM 5.1

         

        I have seen similar posts with this issue on the same device and other devices as well.

         

        Thank you 


        Hi

        I have an LG OLED B7 and since the update I can now get my OPPO 203 to play pcm 5.1 when a DTS disc is in use which is great. the volume was a lot lower than when Atmos is playing. however it means I don’t need another Blu ray player.

        ledzep1Author
        Headliner II
        November 18, 2020

        Can anyone from Sonos please advise, this might be more of an LG CX and latest LG models issue, but your update caused it.

        Thank you

         

          khaz22
          Avid Contributor III
          November 18, 2020

          I was really hoping that today’s speaker update was going to fix this.  Anyone able to see if this was addressed? The 5.1 content from Netflix through my ATV still shows Multichannel 7.1

          billiejoe87
          Chromatic Producer I
          November 19, 2020

          Can anyone from Sonos please advise, this might be more of an LG CX and latest LG models issue, but your update caused it.

          Thank you

           

          Exactly. To be honest even if the LG OLED is passing through a 7.1 LPCM signal, the Sonos Arc should be able to downmix it to 5.1. There is no such thing as Dolby Multichannel PCM 5.1 as the Sonos reports with certain content either, so clearly the first version of LPCM support on the Sonos Arc is buggy.

          1 x Arc, 1 x Beam Gen 2, 1 x Amp, 2 x Sonos In Ceiling Speakers, 2 x Sub, 4 x Sonos Ones, 2 x Sonos Era 100, 5 x Symfonisk Lamp (Gen 2)
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