Looking to crowdsource some ideas to move to Dolby Atmos/Auro 3D setup from my 9.1 system (5.1 + FW + SB). The main challenge is my GIK cloud which is six 244s using the GIK mounting brackets. As such, it is 12' wide and 4' deep and hangs about 10" down on the ceiling. The cloud occupies where the top front Dolby Atmos speakers should go.
In picture below, MLP is shown in yellow, speakers in red, and GIK traps shown in black. The MLP is about 8.5-9' from the center channel speaker. The GIK cloud roughly splits the distance from MLP to center channel speaker.
I don't want to mount speakers into the ceiling, so I was hoping to do 6 bookshelves mounted high up the wall above the mains, surrounds, and rear surrounds. This would sort of be a hybrid Auro 3D/Atmos setup where the front heights and rear surround heights would be active for Atmos, and the front heights and surround heights would be active for Auro 3D.
1) I could mount the front heights on a 12" bracket bringing them below the cloud, angled down to MLP. The only drawbacks here are: I would lose this 12" of height effect and also if any sound traveled between the cloud and ceiling and came out towards the listening position, this might sound odd (although I don't know if this would happen?).
2) Are there any other mounting options people have done for the cloud which can get it mounted to the ceiling, rather than hanging down on the GIK brackets? This would allow me to take the front heights higher up and to remove the air gap concern in 1).
3) If I did say to heck with the front heights, which single pair of Atmos/Auro 3D height speakers has the most effect? I ask this because the processor I'm looking at, the Marantz AV8805, does *not* allow rear surround heights and rear heights. All combinations of 4 or greater height speakers *require* at least one pair to be front heights.
Thanks for the input!