Hi allI have a Samsung UE55AU8000 TV, which is connected a Ray via optical cable. I use the Plex app on the TV to watch my movies, which are stored on my Synology DS224+ NAS. My movie collection is encoded with HEVC. I like a lot of old films from the 40s and 50s and many of these have AAC Mono audio. When I play one, there is no sound from the Ray :( To get sound, I have to go in to the TV Settings > Sound > Expert Settings, and change Digital Output Audio Format from ‘Auto’ to ‘PCM’ and I’m getting really fed up of having to do this. Can someone explain:The reason for this; I’d expect mono to be a fairly simple thing to deal with, and regardless of how many speakers there are, they should all simply play the same mono signal. Would that not be a better solution? If my solution is the correct one, if not, is there another way of dealing with this? I have ordered an Apple TV 4Kand intend to use the Plex app on that instead of the one of the TV. Not for this reason especially, but because it’s supposed to be a lot faster than the TV Plex app, and just a generally more enjoyable experience. Am I still going to be dealing with this same problem when that is connected?Any help is appreciated - thanks!

Trending Lyricist I

Answered

Why wont my Ray play Mono audio?

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Hi all

I have a Samsung UE55AU8000 TV, which is connected a Ray via optical cable. I use the Plex app on the TV to watch my movies, which are stored on my Synology DS224+ NAS. My movie collection is encoded with HEVC.

I like a lot of old films from the 40s and 50s and many of these have AAC Mono audio. When I play one, there is no sound from the Ray :( To get sound, I have to go in to the TV Settings > Sound > Expert Settings, and change Digital Output Audio Format from ‘Auto’ to ‘PCM’ and I’m getting really fed up of having to do this.

Can someone explain:

The reason for this; I’d expect mono to be a fairly simple thing to deal with, and regardless of how many speakers there are, they should all simply play the same mono signal. Would that not be a better solution?
If my solution is the correct one, if not, is there another way of dealing with this?
I have ordered an Apple TV 4Kand intend to use the Plex app on that instead of the one of the TV. Not for this reason especially, but because it’s supposed to be a lot faster than the TV Plex app, and just a generally more enjoyable experience. Am I still going to be dealing with this same problem when that is connected?

Any help is appreciated - thanks!

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brokenboxesAnswer

Trending Lyricist I

I received my new Apple TV 4K today. After setting it up and playing the above film and several others with mono audio, there is no longer a problem. The Apple TV 4K seems to convert any audio to multichannel LPCM. Problem solved.

Glad I didn’t spend hours tinkering with Plex settings, or transcoding my whole library, eh!

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Ken_Griffiths

@brokenboxes,

As per the attached screenshot, the transcoder on the Plex server works automatically and so if it’s not transcoding your movie audio automatically then yes you do need to convert the movie files to get them to play in a compatible Sonos Home Theatre audio format as stated here:

https://support.sonos.com/en-us/article/supported-home-theater-audio-formats

Handbrake is perhaps worth a try to see if that might work for you.

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brokenboxesAuthor

Trending Lyricist I

@brokenboxes,

As per the attached screenshot, the transcoder on the Plex server works automatically and so if it’s not transcoding your movie audio automatically then yes you do need to convert the movie files to get them to play in a compatible Sonos Home Theatre audio format as stated here:

https://support.sonos.com/en-us/article/supported-home-theater-audio-formats

Handbrake is perhaps worth a try to see if that might work for you.

Never mind.

It remains a mystery if the Apple TV 4K can convert from mono to stereo PCM. Who knows. I guess I’ll find out when it arrives tomorrow. If not, I’ll have to re-acquire the films in question from a different source and be a bit more careful with the audio format.

I’ll not bother with converting, though appreciate that is one solution.

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brokenboxesAuthorAnswer

Trending Lyricist I

I received my new Apple TV 4K today. After setting it up and playing the above film and several others with mono audio, there is no longer a problem. The Apple TV 4K seems to convert any audio to multichannel LPCM. Problem solved.

Glad I didn’t spend hours tinkering with Plex settings, or transcoding my whole library, eh!

Corry P

Sonos Staff

Hi @brokenboxes

Welcome to the Sonos Community!

I am glad to hear that upgrading your Apple TV fixed this issue for you. Thanks for updating the thread!

I had just obtained a version of “The Night of the Hunter” to play on Plex, but only the commentary was in mono AAC. As it took me a while to get it, I figured I’d share my findings anyway:

It did play, and I could hear the audio. Looking at my Sonos app, Stereo PCM was reported. I assumed this is because my TV output format is set to Auto, so I tried Passthrough instead, but I still see Stereo PCM reported. I presume this is because the communication between the devices is informing the Plex app that the AAC codec is not supported by the audio device, so Plex is converting to PCM. Something, somewhere is doing the conversion, anyway. I was testing on a nVidia Shield Pro, but I have Dolby conversion off, so I don’t think it is the system doing the conversion. In terms of Audio, my Plex settings are at their defaults.

Long story short, Sonos Home Theatre devices do not support the AAC codec via HDMI/Optical - only when streaming or playing from Music Library. To play a movie with such a sound track, conversion must be performed at some point in the playback chain to a supported format.

I do now wonder if there was a way to do it with your older Apple TV.

"Common sense is the collection of prejudices acquired by age eighteen." - Albert Einstein

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brokenboxesAuthor

Trending Lyricist I

Hi @brokenboxes

Welcome to the Sonos Community!

I am glad to hear that upgrading your Apple TV fixed this issue for you. Thanks for updating the thread!

I had just obtained a version of “The Night of the Hunter” to play on Plex, but only the commentary was in mono AAC. As it took me a while to get it, I figured I’d share my findings anyway:

It did play, and I could hear the audio. Looking at my Sonos app, Stereo PCM was reported. I assumed this is because my TV output format is set to Auto, so I tried Passthrough instead, but I still see Stereo PCM reported. I presume this is because the communication between the devices is informing the Plex app that the AAC codec is not supported by the audio device, so Plex is converting to PCM. Something, somewhere is doing the conversion, anyway. I was testing on a nVidia Shield Pro, but I have Dolby conversion off, so I don’t think it is the system doing the conversion. In terms of Audio, my Plex settings are at their defaults.

Long story short, Sonos Home Theatre devices do not support the AAC codec via HDMI/Optical - only when streaming or playing from Music Library. To play a movie with such a sound track, conversion must be performed at some point in the playback chain to a supported format.

I do now wonder if there was a way to do it with your older Apple TV.

“Long story short, Sonos Home Theatre devices do not support the AAC codec via HDMI/Optical - only when streaming or playing from Music Library.”

All my movies have AAC audio and play fine; it’s just the mono ones that wouldn’t play. Also, AAC is supported by Sonos according to the documentation.

“I do now wonder if there was a way to do it with your older Apple TV.”

I didn’t have an older Apple TV, was just using the plex app on the Samsung TV. Either way, it now works, I’m not exactly sure on what was going on technically that prevented it.

Corry P

Sonos Staff

Hi @brokenboxes

“Long story short, Sonos Home Theatre devices do not support the AAC codec via HDMI/Optical - only when streaming or playing from Music Library.”

All my movies have AAC audio and play fine; it’s just the mono ones that wouldn’t play. Also, AAC is supported by Sonos according to the documentation.

Please see our Supported home theater audio formats help page. AAC is not listed.

“I do now wonder if there was a way to do it with your older Apple TV.”

I didn’t have an older Apple TV, was just using the plex app on the Samsung TV. Either way, it now works, I’m not exactly sure on what was going on technically that prevented it.

Understood! In that case, I think it was probably just that the Samsung Plex app was a bit limited or old.

Yes, the important point is that you can now watch your older movies - enjoy!

"Common sense is the collection of prejudices acquired by age eighteen." - Albert Einstein

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