When your Roku is set to Auto Detect and you watch a movie with Dolby Atmos audio, what does it say when you go to System > About My System > Arc > Audio In? What does it say with the Roku set to Auto Passthrough watching the same movie?

So for the same movie that should not have Dolby atmos based off of what Netflix menu says and the fact that it’s an old movie...

On auto detect it says Dolby Atmos DD+
On auto pass through it says Dolby digital 5.1

Seems like it should be the same but I think it does sound a little better when on autodetect and reading out as Dolby atmos.

The Sonos Arc will play whatever type of audio the Roku is sending to it. The Arc doesn’t “upgrade” the sound quality at all. I think with either setting, you are getting the exact same audio. But I would keep the setting on Auto Passthrough since it is correctly detecting the audio the Arc should be receiving and actually playing.

Just curious… what movie did you test? I have a Roku Ultra and would like to compare so we can know what audio you should be getting.

I tested Ozark and also the movie White Christmas. With autodetect both are saying Dolby Atmos DD+ for some reason. It really does seem like the surround is better in autodetect but I may be imagining it. 

If it matters its a Roku Ultra 2020 4800R. My TV is sony 900e and the arc is in an HDMI ARC, not eARC.

Thanks for your help. Either way its not a problem. I’m just curious why its displaying atmos and what sound its actually putting out.

Ozark and White Christmas should both play in Dolby Digital Plus 5.1, not in Dolby Atmos.

With Auto Detect, do you hear dialogue coming from the surround speakers? I wonder if it’s playing Stereo PCM 2.0 where you are getting the same audio playing out of every channel. That’s the effect you get watching many YouTube videos. The surrounds are louder only because it is in stereo and not in 5.1 surround.

I just checked, definitely no dialogue out of the rear speakers. It just seems like the rears are a little louder in autodetect compared to auto passthrough. 

I have the IDENTICAL observation as narrated by @jleibner:

Sound Settings;

Roku Ultra - Auto

Samsung Q90 - Passthrough

Roku Ultra’s Auto sounds louder at the same volume level and better - Sonos Arc shows Dolby Atmos for movies / shows that I know are not in Dolby Atmos.

This entire Sound ‘Stuff’ and their Settings are causing much confusion - as you know, each device - TV, Roku - has its own Sound Settings as sound passes from device to device.

I can relate to Passthrough if my concept is correct that devices receive and pass Sound in the original Sound format without any changes. The Arc does show Dolby Atmos correctly if Sound is Atmos. However, in my opinion, Sound is certainly better using Roku Ultra’s Auto setting and leaving Samsung TV’s Sound to Passthrough.

I will try to set the TV Sound to Auto, and try Roku’s settings for Auto and Passthrough for more observations - well more brain damage!

I hope experts on Roku, Samsung and Sonos Arc will put forward a clear concept and specific Sound settings to  bring this confusion to an end.

Thanks.

... In Partnership and Service,

Raj Dhir 

@ceiling20 I would keep the Roku and TV on the settings that results in the correct audio being detected and displayed in the Sonos app under System > About My System and under Sonos Arc, “Audio In:”.

Dear @GuitarSuperstar,

Thanks - can you kindly add some more narrative to help relieve our brain damage. Why is the sophisticate Sonos Arc device not doing its work to identify the correct audio signal?

... In Partnership and Service,

Raj Dhir 

@ceiling20 Based on what I’ve read on the Roku forums, it seems like the Auto Detect setting makes the Roku detect the best possible audio the Sonos Arc can handle (which is Dolby Atmos) and tries to convert whatever audio signal it receives up to “Dolby Atmos”. That’s why everything you play with the Auto Detect setting is being detected as Dolby Atmos by the Sonos Arc. So this issue seems like more of a problem with Roku than a problem with Sonos.

I would stick with the Passthrough setting so the Arc plays the correct and original audio signal. But if you think Roku’s converted form of “Dolby Atmos” sounds better to you ears, stick with the Auto Detect setting. At the end of the day, that’s all that really matters.

Thanks @GuitarSuperstar,

I receive your nice narrative ...

"Receive with simplicity everything that happens to you." - Rashi

You are awesome!

... In Partnership and Service,

Raj Dhir 

@GuitarSuperstar,

Roku Auto Sound - ABC News, CNN showing up as Dolby Atmos on Sonos Arc! - unbelievable!

Since Roku Ultra is connected to the TV and the Sonos Arc to the TV via. their appropriate HDMIs, I wonder how the Roku knows about the Sonos Arc as it upgrades the sound it is receiving to ‘Atmos’. Also, Sonos Arc is getting fooled to identify a variant of ‘Atmos’ as Dolby Atmos.

If Sonos, Samsung and Roku are reading this, I hope they can put an end to this nonsense.

Regards.

... In Partnership and Service,

Raj Dhir 

@ceiling20 Set your Roku to passthrough and let it go. It works as it should, and it’s not worth losing sleep over.

Samsung Q90T and Roku Ultra both set to Passthrough - Sonos Arc is showing correct audio in.

Roku is certainly dominating the Sonos  Arc - they need to partner instead in the best interests of their user community.

To the next mile …

Regards.

... In Partnership and Service,

Raj Dhir