You didn’t specify a model #, but there is a good table here:

https://www.rtings.com/tv/tests/inputs/5-1-surround-audio-passthrough#:~:text=5.1%20audio%20passthrough%20allows%20you,to%20a%20receiver%20or%20soundbar.&text=We%20also%20test%20passthrough%20over,%3AX%20object-based%20formats

If i read that table correctly, your TV can only passthrough DD 5.1 over ARC. Atmos will not work for you.

Thanks Controlav.  Appreciate your response.  I have the 65S425.

You are correct, does not have eARC and cannot pass Atmos through true HD.

However, my understanding (perhaps incorrect?) was that there Atmos data can also be passed through via DD+ on this TV via the ARC connection…?   Lots of postings suggesting this to be the case, but I may be getting misinformation.  

Given that the ATV 4K only has a single HDMI output, how might I configure this to get Atmos sound out through the HT system (if possible)?  I only use the TV for video from the ATV box, no video coming through the roku system.  

Thx!

Hi there, I’ve got the 75 TCL 615R, connected to the sonos arc, i get no dolby atmos from the tv’s netflix, prime and disney channels at all, cycled through all the audio codecs in the tv and get no atmos just dolby digital 5.1, but when i play any content from the tcl dolby app it gloriously show the very elusive dolby atmos on sonos app. i was planning to buy an apple tv 4k just to get that very elusive dolby atmos, but it seems that it wouldn’t work. I read that hdmi arc can output atmos through DD+ embedded with atmos but its not working, It’s very disappointing to invest on hi end gear that doesn’t deliver.

Quite a set-up you've got there, and was thinking that's the future of what my system would be. Had the TCL 615R way before the Sonos arc, and can't exchange the TV at this point. I'm hoping for a firmware update from TCL or from sonos that would make the Sonos arc Atmos work on our tv, and yes I read from a lot of sources that Sonos arc should be able to output lossy Atmos from DD+. 

How's your setup so far any good news? 

A follow up have you tried the "passthrough" on audio settings? Btw try playing any video from the Dolby channel in your tv and you will see the Dolby Atmos on your Sonos app, it just shows that TCL R6 to Sonos arc is capable of doing Atmos ... 

So…

Have confirmed that TV can send Atmos signal to Sonos, as you suggested via Roku dolby channel app.  

Have tried setting tcl setting to passthrough.  Still no good.  ATV (running current tvOS 13.4.6) doesn’t seem to be able to push Atmos to the Sonos system through the TV.  Per everything I’ve read, should be sending lossy Atmos through DD+.  In ATV A/V settings, audio format should have options for “immersive audio” and “Dolby Atmos” per the apple support site, but those options don’t exist, and the best I can get is DD+ 5.1…  If anyone has made this work, would love to know how!    Thanks.

Yes a good amount of LG tv owners have had luck with the ATV hdmi to LG hdmi arc to SONOS ARC , I assume you know that there was a decrease of bandwidth on streaming services due to the covid thing,  so I tried to connect my Oppo BDP 130 to TCL , put in Superman vs Batman blueray disc with Atmos and nothing just DD+ 5.1 on the Sonos arc what a bummer . Still that elusive Dolby Atmos from a high end Atmos capable soundbar.

AZMITCH

Finally Dolby Atmos on Netflix and Prime via NVIDIA SHIELD 2019 ! Basically plug and play, Dolby Atmos confirmed on Sonos app the only caveat is that Disney+ although displaying Dolby video and Atmos in the channel only outputs DD+ 5.1 on Sonos app, with the additional investment we ought to have Atmos on Disney and more ! 🤨 

Finally I get Atmos on Disney+ on Nvidia shield , I just turned on the tv clicked on a starwars movie and bam! Sonos app confirms it's on Dolby Atmos DD+, no settings no tweaks it just worked . The Nvidia shield is fast , has games and upscales like a dream, additional expense but all worth it! Thanks and Godspeed everyone !  

Hi, Your posts helps! I have a TCL 75R615 and I am waiting on Sonos ARC that I ordered. Since the TV supports Dolby digital plan and has an ARC port, I was hoping to get Lossy Atmos sound output via all the TV's native apps. Are there any other other findings? Do you think app Roku updates of Netflix and Amazon Prime Video will enable Atmos output from those Apps as well? I also have an Apple TV 4K and wondering it the Apple TV's Netflix or Amazon app + TCL 75R615 will output Atmos on Sonos ARC? Overall do you think Sonos Arc is worth buying with TCL 75R615 ?

Hi, 

I have the same issue - no atmos on arc with Tcl tv and apple tv. The source is Netflix. Tcl can process DD+ and I can see DD+ in sonos app. Am I right that this the issue with appleTV? If I connect nvidia atmos is working?

Thanks

Honza

Do you have an Apple TV 4K? Do you have a premium subscription on Netflix? Have you double checked your Apple TV’s audio settings?

Yes I have premium ultra HD. However in Netflix app I even can not see dolby atmos symbol when I browse movies. There is only 5.1 symbol. In apple tv setting it offers only stereo or dolby digital 5.1 there is nothing more in sound option.

On your Apple TV 4K, go to Settings > Video and Audio and select Audio Format. Under Immersive Audio, check that Dolby Atmos is on.

Audio format offers only change format - on. New format - dolby digital 5.1 or stereo. Nothing else. I also tried to use new hdmi cable. Nothing changed.

Either your TV and Arc aren’t set up correctly, your TV isn’t capable of passing through Dolby Atmos, or your Apple TV isn’t an Apple TV 4K model.

Apple tv is 4k for 100%. I think that tv is not able pass atmos, which is really weird because it can pass DD+. As far as I know netflix uses lossy atmos which is carried by DD+. So I thought that every tv with hdmi arc which can procces DD+ is also cable to pass atmos from netflix. Which obviously is not true

Just because a TV can pass through DD+ doesn’t necessarily mean it can pass through Dolby Atmos. What is the specific model of your TV?

TCL 65dp600

https://www.displayspecifications.com/en/comparison/da70ba839
 

Anyway from this matrix it looks to me that it should work.

https://support.sonos.com/s/article/4844?language=en_US

That page says nothing about audio-pass-through over HDMI-ARC, as that is seldom listed on spec pages. rtings.com is the only reliable source for that info, and it does not list that TV.

Again, just because your TV can pass through DD+ doesn’t necessarily mean it can also pass through Dolby Atmos.

Have you tested Netflix or VUDU on your TV’s native apps to see if they play Dolby Atmos?

Hopefully this helps TCL owners, but I have a TCL R613 (similar to 615/617) and I'm able to get DD+ (Lossy Atmos) via Disney+ and VUDU native apps.

I don't think DD+ is available on native Netflix yet. I have the Arc connected to the ARC port. Just standard connection.

I’ve got a very similar setup. I had lossy atmos on the firestrick 4K but then “upgraded” to ATV4k and lost atmos on prime Netflix and Disney 

From all online research and trial and error with settings I think I’m SOL. Options are buying the Arcana FeuryHD eArc switch, upgrade TV or wait and hope for a TCL update. 
 

I do like the ATV4K Dolby vision - the picture quality is stellar. But after buying the ARC for ATMOS I just may switch back to the Firestick 4K 

GRANTED can I even here what DD+ is vs just 5.1 maybe not.  The full Sonos Arc + subs + surrounds is a very nice upgrade over my old AVR 5.1 

really wish there was another HDMI on the Arc  

Didnt Noah put 2 of everything on the ship...?