Assume this is me Gradds. Due to the evil influence of the 12 inch black disc, a lot of my DIY time of late has been in the direction of phono stages (completed and functioning well), DIY arms (80% completed and non functioning) and lots of listening.
I did a major tweak on the horns. Took the jigsaw to them! Instead of damping the sidewalls of the resonant enclosure, I removed them so you can see straight through from one side to the other.
I glued the bases on and that cleaned up a bit more of the panel honk around the mouth. I think the main problem with how they sound is intrinsic to 2 things. One is whizzer cones, the second is MDF. I suspect that if I build using real wood or ply then any resonances, although possibly peakier will be less broadband and more harmonic making them more musically invisible. Cello's that sound like cellos not like MDF panels.
The speed and dynamics are still great and i will get back to them, problem is that there's still tweaking of phono stage, building preamp, finishing poweramp, rebuilding speakers and finishing unipivot still to go.