I need to tilt the Arc forward to maximise the height channels effect. Try that.
Details below:
In youtube, someone mentioned that:
“Until last night I wasn't hearing much from the Atmos effect, but now I am. I had to move my listening position forward 6 inches then the bar forward 6 inches. I then used the brown spacers (second from the thickest) under the rear of the bar, Atmos effects kicked in. The bubble for the effects seems rather narrow. I am now sitting 9 feet from the bar. 8 feet is where the top firing speakers are the strongest. I just can't justify shrinking the room another foot .”
It seems, as I always thought, that due to the fixed angle of the upward firing woffers, there must be a sweet spot for the maximum height effect.
At the moment, I am settled with lifting the rear of the Arc by 10mm.
Before, I could not tell any difference between DD5.1 and Dolby Atmos when I switch between the two.
Now, I can feel I am in a sound bubble instead of a sound ring. Happy with Atmos, finally.
I find that the sounds from the forward firing speakers are not noticeably affected in this angle of tilt.
The ceiling height is 2500mm, the seating position to the Arc is 2400mm, the height of the Arc from the floor is 550mm ang the ear level is 1000mm above floor. That is my sweet spot for Atmos. The ceiling is uniform, level and flat.
I have the Sub and two One SL’s as rears.