Hello I have 2 things that are outstanding from DIY ,and in Europe. Eminence makes a great new $200 each
Neodymium 15 much fast more defined then any previous for open basket ,get rid of the ceramic,
Also. The Beyma 150 TPL Horn  is a fantastic driver on every level  also using Neodymium  magnets 
Kapton driver with high purity copper, not aluminum like most as a conductor. 1k -23khz  very clean and over 
100 db efficient  drivers are $800 retail a pair.  That would truly be  good ,even in a 12 or 10 inch driver for 
Smaller rooms this would still be about 95 db efficient if padding down the  Beyma driver.
I seen  a couple OB units while in the UK visiting friends these sounded  very natural , dynamic,and powerfull 
Around 30 hz in room .   Wonder if Clayton was working on something like this ?