The Kappalite and 12cx isn't the same driver so you might misunderstood our discussion above.
No, I didn't think that. I was just lazy with the model name Kappalite KL3012CX.
Thanks for the link. Interesting reading.
Joseph Crowe did a Beta-12CX build and compared it favorably to B&C 12CXT.
Joseph Crowe's DIY Speaker Building Blog: Eminence Beta12CX and Selenium DT220TI
Joseph Crowe's DIY Speaker Building Blog: Eminence Beta12CX and Selenium DT220TI
Relatively new ribbon coaxials from radian might be worth looking into. Developed by Igor Levitsky of BG Radia fame.
Coaxial-Ribbon - Radian Audio
Coaxial-Ribbon - Radian Audio