The other day I was trying to clear out some junk to make space, when I realized I had been squeezing past a pair of raw particle board boxes for untold years. I can't even remember why I made them, but their dimensions - 10 1/2" by 14 1/2" by 27" - were perfect for the HUMAN 81+. So I drew some lines and dots on them, played with my drill press and a pair of routers, glued a bunch of braces in, covered them in speaker fur to hide the ugly, and loaded them up. They lived in the listening area as an example of what the larger cabinet size sounded like compared to the smaller HUMAN 81 until they were replaced by production cabinet versions of the 81+.
This is a tool I picked up a couple of years ago that makes cutting circles easy. A 1/8" pin is placed in the appropriate "compass hole", and you drill a 1/8" pilot hole at the center of the circle you want to cut. Cut the rabbet (driver inset) first, then the through-hole.
This shows the rail I glued to the sides, which then supports five cross braces, and also the cross brace on the baffle just above the woofer hole.
An old industry trick is use the rather substantial chunk of material removed when cutting the woofer hole to "beef up" an interior panel, in this case, the rear just below the input terminal hole.
Gluing speaker fur to the ugly particle board one side at a time.
I didn't say they were pretty. The fur is crudely trimmed back, crossover installed, wires secured and the box stuffed with polyester batting.
The parts are finished, installed, and playing. Excellent!
The grill is not cockeyed. Really, it's nice and straight. It's the picture that is warped.