Answered

Sonos Arc audio format PCM despite LG 65UP8000 with eARC and Amazon Fire Stick 4K

  • 22 December 2021
  • 8 replies
  • 1039 views

I have Sonos ARC, Amazon Fire Stick with 4K (using Tomorrow War as a test which is Atmos content), and LG 65UP8000 (2021 model with eARC). In LG audio settings, Sound Out = HDMI (ARC) Device, eARC Support is toggled on, Digital Sound Output = Pass Through (other options are Auto and PCM). In FireStick 4k Settings, i have Surround Sound set to Best Available (Plays best audio format based on your connected HDMI device and content being played. Support Dolby Atmos, Dolby Digital Plus, Dolby Digital, and PCM). When i play Tomorrow War, the S2 app shows the Audio Format is Stereo PCM, and i don't know why. I called Sonos support, and they basically said the issue is on the TV side. But, I enabled the audio settings to allow me to stream Atmos content. Does anyone know why I am not getting Atmos audio? or why im not even getting Dolby Digital but rather Stereo PCM?

icon

Best answer by BMF 22 December 2021, 23:01

View original

This topic has been closed for further comments. You can use the search bar to find a similar topic, or create a new one by clicking Create Topic at the top of the page.

8 replies

Userlevel 7

If you set Digital Sound Out to Auto, is there any difference?

You might have to manually select the Dolby Atmos audio track AFTER you begin streaming the Dolby Atmos content too.

Userlevel 5
Badge +13

I don’t have that TV, but I have noticed that the FireTV stick 4K and 4K Max behave this way for me too.

 

My TV does not support Atmos, so not expecting that, but default was stereo PCM.

 

I have to hard code the audio on the FireTV stick from “Best Available” to “Dolby Digital Plus” or “Dolby Digital” to force it to not use PCM.

 

on FireTV

 

Settings>Display and Audio>Audio>Surround Sound

 

try changing it from “Best Available” to “Dolby Digital Plus”  see if that gets you Atmos… they may even be an “Atmos” option as your TV supports it.

 

hope that helps.

 

personally, I have been disappointed with FireTV…. So many little quirks like this

 

 

Check that the HDMI input audio format on the TV is set to Bitstream and not PCM …and also that DTV audio is set to Auto (see screenshot).

Then It’s a case of sending DD+/(Atmos) or often ‘Auto’ audio output from your connected devices. 

Weird, while the fire stick audio settings imply it needs to be set as Best Available to get Atmos, it results in audio format of Stereo PCM showing in S2 app. When I changed this setting to Dolby Digital Plus, it shows in S2 app as Dolby Atmos  (Dolby Atmos DD+ though in About My System). So the issue was the fire stick, and it is preventing me from getting Atmos True HD

Userlevel 5
Badge +13

FireTV stick is really weird for me, thought it might just be  my TV.

 

I had a Beam Gen 1 and a FireTV Stick 4K (not max), I swapped the Beam for a Gen 2 and as I lost the remote for the FireTV 4K, I got a 4K Max as it was not much more expensive than buying a new remote when it was on offer.

 

The Max is the same as the 4K in that I had to force it away to get anything other than PCM. 
 

With the beam Gen 2 I had the option for DD+ so went with that.

 

TV apps all work fine, but BritBox on Max won’t load most of the time, Disney + will only play in HD and not UHD.

 

just tried an Atmos title in Prime and to my surprise It DID play ATMOS on the Gen2…. but not in Netflix or DIsney +
 

it’s a very buggy platform, thinking of getting an AppleTV to use instead.

 

EDIT…. Actually Apple TV will not do ATMOS over DD+, back to the drawing board.

Userlevel 7

Weird, while the fire stick audio settings imply it needs to be set as Best Available to get Atmos, it results in audio format of Stereo PCM showing in S2 app. When I changed this setting to Dolby Digital Plus, it shows in S2 app as Dolby Atmos  (Dolby Atmos DD+ though in About My System). So the issue was the fire stick, and it is preventing me from getting Atmos True HD

Streaming services like Prime Video don’t use the lossless Dolby TrueHD version of Dolby Atmos. They use lossy Dolby Digital Plus instead because of limited bandwidth when streaming. Dolby TrueHD/Dolby Atmos audio is primarily used on Blu-ray discs.

Weird, while the fire stick audio settings imply it needs to be set as Best Available to get Atmos, it results in audio format of Stereo PCM showing in S2 app. When I changed this setting to Dolby Digital Plus, it shows in S2 app as Dolby Atmos  (Dolby Atmos DD+ though in About My System). So the issue was the fire stick, and it is preventing me from getting Atmos True HD

Streaming services like Prime Video don’t use the lossless Dolby TrueHD version of Dolby Atmos. They use lossy Dolby Digital Plus instead because of limited bandwidth when streaming. Dolby TrueHD/Dolby Atmos audio is primarily used on Blu-ray discs.

 

So if i get Apple TV 4K, would it be True HD?

Userlevel 6
Badge +10

No all streaming services only stream in dd+

Not device dependant