Have you adjusted the height audio level of the Arc in the Sonos app?

Yes I did I set it at +5 or +7 even. 

I just measured my distance from the Arc. I'm 8 feet away. 

What specific Dolby Atmos content are you testing? Just because you are watching something in Dolby Atmos doesn’t mean you’ll hear height effects all of the time. The height channels are actually used very seldom with most Atmos content.

Try to sit 5-7 feet away from the Arc and set the height audio level to +8.

I'll try to see if I can move my couch.

Any advise on Truplay? Should I cover the bubble of the MLP or the whole room?

It is recommended to cover the entire room. But you could try both ways and see which one produces the best results to your ears.

I have increased the height channel level and done truplay twice. The height effects seem to be coming from the front rather then above.

I watched a video by Peter Pee, he advised to raise the back of the Arc based on the seating distance. Does this make sense as it will block the front speakers...

You could raise the back of the Arc a little. This would change the angle of the upward firing drivers to reach a further distance from the Arc. But this shouldn’t be necessary if you are already seated 5-7 feet from the Arc.

What specific Dolby Atmos content have you tested? You need to find content with clear height channel effects.

If you have a premium Netflix subscription, try testing the film Roma at around the 1:03:25 mark. For a few minutes you should clearly hear the trees burning/crackling above you.

I tried the wandering earth with electricity sparks. Seems to be coming from the front sound stage. 

Will try Roma.

Do you think the Arc is faulty? I don't think this is a fault though...

I’ve had the Sonos Arc with rears and subwoofer for 4 months and I’ve NEVER heard the height channels. I’ve watched a variety of Atmos titles from both disc and streaming. I’ve raised the back of the unit. I’ve run Trueplay over and over. I’ve brought my seating distance closer. I climbed a ladder to if I could possibly detect the reflected sound off my concrete ceiling. I’ve sat on the floor. 

If you’re able to enjoy anything approaching real Atmos sound from this unit, congratulations.

Try to think of Dolby Atmos more as directional moving sound. It’s not going to be full above your head falling down on you as such.

If you think you have issues however with the channels, grab this file I have uploaded for you. It’s Dolby-Test-Tones_5_1_2

Will be able to hear each channel separately and should be able to clearly work out then if your height channels are working.

https://mega.nz/file/IP4HTAYI#wcOhds2vx4cfOamCTarLxNEC8Rx3zNeIy9P8gtKzfGk

Forgot to mention if the channels seem fine, then download the Amaze (lossless-Atmos) file from here:

https://thedigitaltheater.com/dolby-trailers/

Then play the video with the heights on -10, then play it again with it on +6. Yes it will still sound like it’s coming from the front a bit, but you should definitely be able to hear the immersive sound stage so the rain in the video sounds like it’s created a bubble around you.

Do you have rear speakers or the sub at all ?

Have you also confirmed in the app you are definitely getting Dolby Atmos and when playing the content if you click ‘about my system’ does it day Dolby Atmos DD+ or Dolby Atmos (trueHD)?

I don’t believe the Arc is faulty. I think it has more to do with the Atmos content you are testing and what your expectations are. If you are seated about 6 ft from the Arc, the height channel effects should sound like they are coming from a spot on the ceiling in between you and the Arc, not directly above you.

Are your ceilings flat? Do you have a ceiling fan or anything else on the ceiling?

Thank you very much. I will try reducing height volume to test. Most of it is in DD+ (Atmos)

I do have a ceiling fan.

I am a seated about 7 to 8 feet from the Arc. The Arc is about 6 to 7 feet from the ceiling. I think it may be too high but unfortunately i cannot wall mount the Arc as my TV would have to shift upwards which would lead to an uncomfortable viewing angle.

I have seen some dudes mention spacers. Are they in the box?

@Kelvin_M The ceiling fan might be the problem. If the fan is located where the upward firing drivers are bouncing the audio off of the ceiling, it will minimize the height channel effects you will hear from above. Do you mind posting photos of your setup that includes the Arc, ceiling fan, and couch?

There are no “spacers” in the box.

I was just reading about some of these guys using spacers to reposition the Arc. Either way I will try and bring my Arc closer to my listening position and see if that helps.

Due to heat problems I have to place my PS5 on my console. It does block the side firing speaker but I don't think that effects the height performance. Will share some pictures in a while.

I have moved my PS5 further in. The side speaker is no longer blocked.

Done truplay again. 

How far is the ceiling fan from the TV wall? In the photo, it appears that the ceiling fan is turned on. Have you tested the height channels with the fan turned off?

Have you tested the scene from Roma yet?

Hi all.

I think I have resolved the issue. Make sure to set your TV's digital audio output to passthrough and not auto. I can now hear Atmos height effects. 

Auto let's the TV process the audio signal. Passthrough will send an unfiltered audio signal to the Arc. 

Hope this helps those who are facing the same issue. 

Sonos Arc+Sub+One+One SL

Hi @Kelvin_M 

Thanks for sharing your fix!