Hi Chris.

Looking like an amazing build ... you say "the front 9 speakers" but you seem to have drawn out / have back boxes for 12; what are the horizontal ones to be? They don't look to be the right shape for in-wall subs I don't think.

Cinema: Meridian 271, 3 x DSP640 (behind screen), 4 x DSP320 (in-ceiling), 4 x DSP3100 (surrounds), 2 x AC12 (interface). 2 x Perlisten D12s subs, Lyngdorf MP40 processor. DT 145" 2.35 AT screen. Sony VW870 projector & S-T lens, Lumagen Radiance Pro.
Lounge: Roon, NUC, Kef LS50 Wireless + 2 x REL Gibraltar-2 subs

Meridian owner since 1998