Build two boxed and put them next to each other rather than one big one. Can highly recommend doing this. 7 cubic feet per box will give you a nice and low Q as well as an easy to drive system. Go for something like the Dayton HO/HF 18" drivers.
Room| Treated | Sound| Front: Ino Audio i32s, Center: Ino Audio i16s, Surrounds: 6 x Ino a2, 6 x Ino a1, Subs: 6 x Ino Infra-Y|
Picture | Epson TW9300, Seymour Center Stage UF 130.4" retractable 2.35:1 |
Electronics | Arcam AVR390(Dirac Live), 3x Ncore nc400 monoblocks, Emotiva XPA-2 Gen2, EP4000, Panasonic UB700, Allo Katana + Isolator 1.2(Roon bridge/DAC), ATV 4K |