On your additional layers for the ceiling are you leaving a small gap between the wallboard and the ceiling boards each time? It's been difficult finding information regarding the second/third layers as the butt up each time to the wallboard.
LFR1100 VP180HP EP600 M3 In Ceiling x 4 M5OW M2 - Atmos rears ADA1500.5 M3 Outdoor Speakers ADA 1000.8