I just love that, candy for the eyes, ears and mind!!
See how uncomplicated these drivers are, no real need for extreme filters or complicated enclosures... just build it and enjoy good sound! And with just a little more effort it can sound truely great! (speaking from experience) I have built many speakers and have used many expensive drivers and I've never quite seen quality like this offered at such a price.... Also how tough they are mechanically, I mean, have you tried to make the SP60 distort?? It's almost impossible!
Pics can help a lot to diagnose something from any place on the globe...