Looking at the plans, when you build the width (or height not length) can you go anywhere from 15" = 36"? Idea is to build 2 to flatten out the room response.   From what I've gathered, a 72" Long, 18" High, 36" wide should be apples to apples with a 36" x 36" x 36" Tuba HT. Many steer away from the 36" cube of the Tuba HT because they can't get it through the doors in their house...usually some of the interior doors.   I'm many years from a final home so the 72" x 18" x