Based on that bottom photo, it looks like the TV could still be partially blocking the upward firing drivers. How tall are your ceilings? Are they flat? How far are you sitting from the Arc?

Hi thanks for the quick reply here the details:

Distance Us to Arc: 3.20m

Distance Arc to TV: 13cm (5.5 inch) as the template for the wall mount recommended.

Ceilings are a bit in front Above us:

Is there an ancle I can measure if the TV is not blocking the upfiring Speaker? 

How tall are your ceilings?

The seating distance of 3.2 meters is probably a little too far for you to even hear the height channels.

The best way for you to test if there is enough clearance between the Arc and TV is to find a Dolby Atmos source with clear height channel effects and test it. But I would sit/stand about 1.5-3 meters from the Arc while testing.

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. Make sure you are listening to the original Spanish audio track.

Ceilings are about 2.50m high.

I will check Netflix, thank you for the recommendation!

Best bet would be to change the arc wall mount for the Sanus extendable Soundbar Wall Mount. 

1 min 22 on video to see it in action. 

https://youtu.be/r1uT2zbhU2E

https://www.sanus.com/en_GB/products/speaker-stands/wssawm1/

I just adjusted the distance from >3.25m to 2.85m now I hear the sound above from the upfiring speakers much better. Unfortunately I hear them from the front and from above. But it is much better now. I really appreciated the following scenes in Dolby Atmos:

Netflix on ATV using HD Fury Arcana Adapter:

- Roma: 1:03:25

iTunes on ATV using HD Fury Arcana Adapter:

- Mission: Impossible: Fallout: 1:54:00

- Spider-Man: Far from Home: 1:17:40

- The Matrix: 1:41:05

- Spider-Man 2: 0:35:00