Great stories, baffled Loudspeaker. I thought only white van speakers had bricks in them!
I wonder if the assembler on our AR-4x's went to sleep that night, wondering where that lost jig ended up that day.
On second thought, I think it probably aligned the crossover back board/assembly to the cabinet. I don't recall exactly how it was orientated in there when we found it. Looks like it might have fit better in the other lower corner as pictured. I would imagine they pre assembled the crossover before it was installed in the cabinet. It's probably all chewed up from a wayward stapler shots.
My son and I are working on a pair of AR-4X's. We found this L-shaped piece of masonite(?) with a wood block glued to it inside under the insulation. It fits just around the between the cap and the edges of the cabinet. I figure it must have been a jig for installing the cap and forgotten about upon assembly. I hope it didn't buzz when the speaker was playing!
wo