I just ran some calculations and it looks like according to the diagram I do have proper angular separation. So that's good.
For the folks not really sure how low their surround speakers should be, I can share my experience.
First, from the main listening position, my ceiling speakers top front are 48? elevation angle. Top rear are 47? elevation angle.
I have adaptive dipoles at my sides. The center of the speaker face is 26 and 1/2 in above the ear. The top of the speaker is 7 feet above the ground. But I figure the calculations are best based on the center of the speaker face. Which is about where the woofers are. I have 10 foot ceilings.
When I first posted about not having atmos, I had remarked in this thread that it did sound like sounds were coming from above me based on my side surrounds. That's because my side surrounds are above the ear, naturally. [IMG class=inlineimg]/forum/images/smilies/smile.gif[/IMG].
But once I went Atmos, I realize that there is a big difference between having overhead speakers compared to high mounted side surrounds.
I get pretty good separation between sides and top. I can definitely hear when sounds are coming out of my ceiling speakers. Like Mad Max Fury Road on Blu-ray... when the gal fires a shotgun at the rock ceiling. I could hear the Rock and debris coming from my ceiling.
Anyway, I am glad I did not lower my side surrounds. I could have gone one foot lower, then it might be kind of tight for people walking by the seating area. So I left them as is.
Anyway, like the advice given a lot in here, try to get close to the recommendations. It's never going to be perfect. And Atmos really is a cool upgrade.