2x8" PPSL midtops made from junk

I gutted the speakers again tonight in preparation of my next moves.

I had noticed before that the speakers produce distinctive tonal sound when tapped/beaten. Tonight I fired up a very crude software called iSpectrum (very useful for quick and dirty RTA directly from the internal mic) to investigate this. 

I did some bongo solos on the two cabs, and could see distinct panel resonances, with some small differences between the two cabs, due to differing placement of glued in battens. The first cabinet has the crossovers mounted close to the slot -> center of the cabinet. This was a big mistake because it inhibits installation of the second (higher) woofer to the slot. The second cab has the crossovers close to the top of the cabinet. The result is ~320 Hz vs. ~340 Hz main panel resonance. Could almost tune my guitar to the higher one   (never mind the harmonics...... I'll see if I can bother to do some more in-depth analysis on this)

conclusion: more bracing needed, and I have to be very careful to keep the physical layout of both cabs as close to identical as I can, otherwise I will have to EQ the pair individually, and take care to not interchange them by accident 

10 mm plywood is definitely on the thin side - there seem to be no shortcuts when building a midtop. A hard lesson learned. But as we say in both finnish and german: You don't look into a horse's mouth if you receive it as a present  

'scuse me while I ingest some more beer and contemplate my next move 

Here are a few pics from the latest attempt to install the tophats that have been laying around for the past couple of months. 

I still use mainly handtools, but have found an experienced good friend with a workshop and power tools to help me out once in a while. So I have been fortunate enough to learn how to use a plunge router under his instruction. 

I made router templates for the hole and the recess. I marked the place of the tophat with one of those very practical little electric engravers that sometimes can be had at Lidl for 8€. With a few passes i cut through the warnex to bare wood. Then we taped the circumference of the cut, and the underside of the template, and applied some superglue. This is a neat way to hold routing guides in place, omitting clamps altogether. After routing the tape is peeled off, and both template and workpiece survive unscathed.

Since the boxes are built from very thin stock i also had to prepare two pieces of plywood to reinforce the inside of the bottom. I clmpleted the routing and fitting on both boxes, but I ran out of time after this. Next time i will add some more bracing to the other box, seal the top hats with some black adhesive/caulk/whatevee, and reassemble. After that they will be completed. The only further improvement after that might be a grill/foam to make it a bit more tidy, but that is optional and not a priority.

loving that bass mid top too..:-)