What specific Dolby Atmos content are you testing? Try to find a movie or show with discrete height channel effects. If you have HBO Max, try testing the lobby scene from The Matrix.

Also, with a standard 8 foot ceiling, the ideal seating position to hear the height channels the best is sitting 5-8 feet away from the Arc. If you are seated further away than 8 feet, you probably won’t be able to hear much height channel effects above you.

Set the height audio level on the Arc to at least +5 or +6.

I've played various action scenes (Justice League, ext...). Maybe the couch is too far?  Unfortunately I have a small room and a door way so I can't move the couch any closer. I might move the Arc upstairs to a bigger room (smaller tv) and see how it does by itself and put the playbar back in its original spot. It's safe to assume though it the Sonos 2 app is saying Atmos then the arc is playing atmos?

Is there any other way people try and test their Sonos system other than movies?  Is there any kind of app that allows atmos to be tested through Sonos speakers?  

If the Sonos app is showing the Dolby Atmos logo, you should be getting Atmos audio. You can also go to Settings > System > About My System and see what it says after “Audio In:” under the Arc info. It should show “Dolby Atmos (DD+)”.

What specific model TV do you have? What are the audio settings currently set to?

The reason why I mentioned testing The Matrix is because you should be able to CLEARLY hear height effects above you during the first few minutes of the movie beginning with the Village Roadshow logo. Set the height audio level to +10, sit about 6 feet away from the Arc, and start The Matrix. If you can’t hear anything above you, you probably aren’t getting actual Dolby Atmos audio.

Here is a Dolby Atmos 5.1.2 test tones file. Put this MP4 file onto a USB flash drive and plug the drive into your TV to play the file.

http://download.dolby.com/us/en/test-tones/dolby-test-tones_5_1_2.mp4

So I actually did the clip via screen sharing on my iPhone and it worked. All channels are working through this test. Thanks for the link. 
 

Currently my tv is a 50” Samsung 4k UHD model #UN50RU7100F

My content is played through the Amazon 4k Firestick. Fire stick setting is best available sound. TV setting is Sound Output Receiver HDMI. 
Expert settings Digital Output Audio Format: Dolby Digital +, Dolby Atmos Compatibility selected

Again, my app does say Atmos when playing Atmos content.  
 

It must have to do with my room configuration  Couch is 9’ free speaker.  Unfortunately I can't bring couch closer as it would block the doorway to get into the smaller size room.  Ceiling is flat, 7’ high.  Arc is about 4 to 4 1/2’ from ceiling.  Is there a way to feel the high speakers land on my seat that's 9’ away other than turning the audio height all the way up?

Thank you again for the help.  Also are there more links like the one you sent me to test the Dolby Atmos?

It also could be that while the signal is encoded in Atmos, the actual use of all the channels is not there in the source.

I used to get “Dolby Digital” content that was only stereo. 

@Friske Unfortunately your couch is too far away. With your ceiling height, your ideal seating distance from the Arc is around 5-7 feet. There isn’t much more you can do other than move the Arc closer to the couch or move the couch closer to the Arc and adjust the height audio level higher. You could also experiment with tilting the Arc forward slightly to change the angle of the upward firing drivers.

Here are more Dolby Atmos trailers:

https://developer.dolby.com/tools-media/sample-media/video-streams/hd-video-streams/

https://www.heimkino-atmos.de/sonstiges/trailer-downloads-und-testtoene/

Thanks for the links!  If my ceiling is 7’ high do you know how this effects seating?  Closer/farther away Vs 8’ ceilings?  Lowering/raising the ARC from the floor?  Just curious options of positioning ARC higher/lower vs moving couch forward/speaker closer (which isn't really an option).  Thanks again!

I shorter ceiling would move the ideal listening position closer to the Arc. So lowering the Arc away from the ceiling should slightly increase the distance of the ideal listening position. But of course you don’t want the Arc to be too far away from the ceiling where it cannot effectively reflect audio. But you shouldn’t run into this problem with 7-foot ceilings. See this diagram:

FYI… I have 8-foot ceilings and my Sonos Arc is positioned 6 feet away from the ceiling. My ideal listening position to hear the height channels the best is 5-8 feet away from the Arc with my head positioned at about the same level as the Arc. I have the Height Audio Level on the Arc set to +6.

This is very informative. This will give me some direction when playing a little bit with the ARC. Thank you again. 
 

Brian

I also have a sub ones and ARC, Had mine for a bout a year now.. I don't really find much difference between 5.1 or ATMOS sound with the ARC. Never really have heard overhead effects from it and ive moved it all over the place, different heights and closer to me. I have a flat ceiling 7ft tall and im sitting 7ft from the ARC. I would like to see some upfiring rears to be released by Sonos, to see if that can boost the overhead effects etc.

It is surprising that you haven’t heard any height effects with your setup. What is the Height Audio Level set to on the Arc? What Dolby Atmos content have you tested? What TV, media devices, and apps are you using? I can recommend Atmos content where the height channels are very noticeable.

Bro, I feel your pain. I had a Playbar. I was SO excited when the ARC came out; Dolby Atmos. I get NO overhead sound whatsoever. And everything “Dolby Atmos” that can be enabled IS enabled. I have 8’ sheetrocked ceilings. I can sit 5, 6, 7, 8, 9, 10 feet from the TV and NO Dolby Atmos overheard sounds at all. I’ve listened & followed Pe’s advice, ALL OF IT, on YouTube, all for naught.  I’ve tried every type of HDMI cable on the market. I have a Sony 4K bluray player that says it supports Dolby Atmos. I have tried EVERY setting possible on the player. Nothing. I even ordered the $1000 Panasonic blu-ray player from the crutch in the field guys--NO difference, so I sent it back. I am now seriously considering selling my entire Sonos system and buying the new Nakamichi Dragon system. To say that I am disappointed is one of the greatest understatements of my life!!

100% agree.  I sold my ARC and bought a second sub.  Having the second sub with my living room vs having an ARC instead of a Player was worth it.  Playbar is awesome still.  The Nakamichi Dragon system looks cool.

What model TV do you have?

Samsung QN90BD-Q65BL1

Make sure you have the TV set to these settings:

HDMI-eARC Mode: Auto

Digital Output Audio Format: Pass-Through

And, if possible, test the film Blade Runner 2049 on Blu-ray disc. It has A LOT of height channel effects. On your Blu-ray player, set Digital Audio Output to Auto and set the BD Audio Mix and Audio DRC settings to OFF.

I cannot set the Digital Output Audio Format to “ Pass-Through.”   When I try, I get the following message:  “The current audio format input cannot be passed through an ARC connection.”

BTW, all the other settings you suggested, I’ve already done. And I have Blade Runner 2049, (which I love:)  Sonos simply doesn’t project tangible overhead sound thru my ARC. I have tried everything that I can find online...and I mean everything!  All that $$$ and nothing.  GREAT sound, I’ll admit, maybe the best ever...but NO Dolby Atmos overhead sounds. SUCKS!!!!!!!!!!!

Something isn’t right. What audio format is displayed in the Sonos app when playing Blade Runner 2049? Have you tried changing the Digital Output Audio Format setting while the Blu-ray is playing? What is the Height Audio level currently set to in the Sonos app? How far is the Arc from the ceiling? How far are you currently seated from the Arc?

Audio format = Dolby Atmos. Absolutely. Yes I have tried changing the doaf. I have set height from normal to all the way to the top. NO change in sound at all.The ARC is 55 inches from the ceiling. As I said, it doesn’t matter how far I am from the ARC. Pe (on YouTube) suggested experimenting with that distance. I have tried EVERY distance. It simply doesn’t matter. Ironically, when I got the email moments ago about your response, I was, and am still, on Nakamichi’s website.  I’m tired of fighting this battle.  Last night, I watched The Matrix in Dolby Atmos. NO overhead sound. None. Nada. Zilch.

Very odd. I can hear A LOT of height channel effects when I play The Matrix. If you place your ear right next to the upward firing drivers, do you hear any audio being played out of them?

Exactly where are the upward firing drivers?