I received some packages today with some custom made stuff inside. I'll try to get photos up tomorrow.
One thing I did have time to check was a custom adapter that lets us mount a bolt on compression driver to a screw on coaxial. They make adapters already, but the threaded part is too short and won't screw all the way down inside a coaxial to completely seat itself. Plus if you bolt on your compression driver, then screw in the adapter, the bolt heads will hit the woofer magnet and then it can't seat all the way in either. Easy fix though. Get one made from aluminum with a longer threaded post, then grind down the threaded post until it's just the right length to seat itself and still have clearance for the bolts. I tried them out and they work fine. So we could use a DNA-360 on the back of a Eminence 10" or 12" model now.
But, I might have stumbled across something interesting if I can make it work out. It's a mounting plate that gets screwed on the front of a compression driver during manufacturing. Like the plastic part on this B&C DE10:
There's a tapered pointy phase plug hiding inside of that chunk of plastic. Obviously the phase plug isn't long enough to get inside the horn's throat. Well I found a mounting plate that has a much longer phase plug, and it happens to be for a screw on compression driver. I'll need to get photos. When it's screwed into the Eminence coaxial, the phase plug is so long that it actually protrudes up through that small aluminum "horn" inside the woofer. Looks like I need to chop open an Eminence coaxial to show you guys what I'm talking about. I wonder if a phase plug that long would have any advantage? I think it might.
I also have some interesting coaxials. Yes, some are custom made. One looks neat, but probably won't work very well. I think you guys might like some of these.