Hi @dannyboy153.

Thanks for reaching out and for your detailed post, let me help and check it for you.

To better understand, I need to ask a few more details, and the more information we can gather will help us resolve the problem. 

• Is the TV directly connected to the Playbar via optical audio cable?
• May I have the make and model of the TV?
• Have you checked if there are any audio settings on the Youtube app?
• This article lists the audio formats that are supported by your Sonos home theater products.

Kindly try playing audio from Youtube to the Playbar, then submit a diagnostic report through the Sonos app, and reply with the confirmation number. I'd start by reviewing your system as well as the status of the devices, it will help in identifying what's possibly causing the issue.

I’m looking forward to assisting you further from here.

If you have any other questions or run into any issues,  please do not hesitate to reach out,  we are always here to help.

Thanks Annabel,

Here’s the diagnostic confirmation number: 1204478700. 

To answer you questions…

• Is the TV directly connected to the Playbar via optical audio cable?
  • Yes. 
• May I have the make and model of the TV?
  • Sony XBR-75X850C. The YouTube app is install on the Roku Ultra. 
• Have you checked if there are any audio settings on the Youtube app?
  • YouTube app is install on roku. No audio settings. App is uptodate. Other  newer videos plays fine (Ex. Videos that play fine shows “Dolby digital 2.0” in play bar).
  • So I did some testing…
  • Though YouTube app on roku does not have sound setting, the roku itself does.
    • Roku audio S/PDIF set to “auto”. Sonos playbar shows “Dolby digital 1.0” and no sound for old video.
    • Set to “Dolby digital”.  Sonos playbar shows “Dolby digital 1.0” no sound. 
    • set to “Dolby digital plus”.  Sonos playbar shows “Dolby digital 1.0” no sound. 
    • set to “PCM-Stereo”. Sonos playbar shows “Stereo PCM 2.0” and has sound!
    • Stopped test other audio settings with DTS is not worth it as Sonos doesn’t support DTS. 
    • Conclusion:  in “auto” or “dolby” modes, roku try’s to convert the audio of old YouTube videos to Dolby digital 1.0.  Either 1) Sonos doesn’t support dobly digital 1.0 or 2) roku conversion is faulty.  I of course set the roku to “auto” as movies (ex. Netflix) streams in DD5.1 so I’m missing out if I force roku to use PCM stereo. 
    • I also tested the YouTube app on the Tv (Android tv) and played same video fine (Sonos shows play bar “Stereo PCM 2.0.”
• This article lists the audio formats that are supported by your Sonos home theater products.

Hi @dannyboy153.

Thanks for your response and my apologies for the delayed response.

Upon checking on the diagnostic report, it shows that the audio format the Playbar receives is Dolby Digital and cannot be transmitted through an optical cable if the bandwidth is too high, it should be via HDMI. The only audio format supported on Youtube is stereo/PCM. The audio source must be set to output a stereo/PCM signal to get audio from the Playbar.

If you have any questions or concerns, please feel free to let us know, we’d be glad to help.

Thanks Annazel.  Not sure if bandwidth issue, because it’s showing DD 1.0 which to me means a single channel (middle channel)...but don’t know enough about these technical things.  I think Roku is taking youtube and converting it not correctly and you’re right that it should probably be PCM.  In any case, not many videos are impacted, only occasionally old ones.

Hi @dannyboy153.

Thanks for your immediate response.

Have you tried to check the audio settings from Roku?

You may refer to this link from Roku Support and see if it will help in adjusting the audio setting:

https://support.roku.com/en-gb/article/360011704154

Let us know how it goes and if you have any questions feel free to reach out, we’re always here to help.

Yup. If I change the Roku to output PCM-Stereo, it works. But of course I do not leave it at this setting as movies would also be at Stereo vs DD5.1. 

Perhaps try this - set the Roku to output the Dolby Digital audio (not the plus version). Set the TV audio output to Dolby Digital 5.1 (if it’s not set to that setting already) and then shut down the TV completely (not standby) and unplug/power off the Roku device. 

After 30 seconds or so plug the Roku stick back in and power on all. This should create a new ’handshake’ between the Roku and the TV and then see if it works after that.