The 6.5" diameter speakers are some old Bose bookshelf ones I pulled out of the original speaker cabnets (the tweeters were blown) I've had lying around for some time now. It's a simple box I and Richard made of 0.5" thick plywood. The interior top/center wood block is hardwood to prevent it from splitting from the weight on the music stand. The box is at a 30 degree angle and originally spun freely around on the stand so Richard put a compression clamp & knurled knob on the back of the box which also enables the box to be secured at any height on the stand instead of just setting on the stands lower half. No attempt was made to figure out 'proper' speaker enclosure dimensions but it sounds pretty good! One of the pictures shows speaker wiring of which I'll be replacing with heavier guage wire of the same length on both speakers.
The pics with a cardboard 'mock-up' are just that, to help figure out what it would eventually look like.
FYI, my musical stageplay comedy:
My song collaboration: