My Monet cabinets are still in my bedroom staring at me. I've done some studying but don't think I'll turn into a speaker designer overnight. Did some web searching to look at other large speakers from back in the day. Aztec Valencia caught my eye. But waveguide tech is better now and that brings me back to Pi. Maybe I'm at the point where perspiration is better than inspiration.
Wayne, the Helmholtz freq of the Monet cabs is 23.6.
Maybe I should make a cheap front baffle out of OSB and just clamp it to the front, using a gasket to seal it. Then I could check for standing waves, and experiment with damping material. I could change the internal dimension with closed cell foam or perhaps make a plywood internal divider. If I needed to change the position of drivers, I'd just have to cut a new test baffle.