Here's a few pics to keep you from thinking this thread is dead. It's not.
I wanted something slightly different from the normal DIYsoundgroup flatpacks for my Volt 10LX (Atmos variation). I have not yet modified my crossovers to remove the LF hump that comes from the undersized box, but that comes soon. I have been making my own "flat packs." They came out pretty good for a cheap contractor table saw with no dado blade.
I started assembly with some scraps carefully positioned on the inside surface of the baffle so that I could clamp it all up at once.
Once the glue was set on those baffle cleats, I threw them together with glue on all the mating surfaces and clamped them up. A couple drivers work as dead weight.
Here's the current status. I cut the bevel on the side, which extends beyond the back to hide terminals and mounting hardware (not yet finalized), at an angle of 7 degrees. That was about where I wanted them to be for dispersion, and I it passed the eyeball test for looking "right" to me.
I have cut 4 boxes, in various stages of glueing as of this weekend. I need another half-sheet of 1/2" MDF to make the last two side surrounds - and it will eventually be several (hopefully 6) more in a redesigned box for ceiling use once atmos becomes more affordable at that level.