good news extremis lovers

There are some minor differences.  From what I understand they reduced the upper end bandwidth a little bit to provide even more low end capabilities. 

Kevin Haskins of DIY Cable has one of his own as well.  It goes the opposite direction by focusing on improving the response in the 1-3 kHz range but at the cost of reducing the low frequency extention a bit.  This also means it's an easier load to amplify.  He uses it in all his new speaker kits and will not be offering it for sale outside of the kits.  So this means that Bob's driver will be the only one available for your own DIY projects.

Something tells me that if you asking a question like that - you'd probably be happiest with a nice generic midrange car speaker from - say - CDT.

I dunno.

I think that this is always a fun idea to toy with - but the aforementioned problems of integrateing drivers like these into overall vehicular functionality tends be, IMO, far more trouble that it would otherwise be worth.

I mean - I like clean sound and all - but this

is dedication!  Wow.

Maybe I'm wrong, but I betcha haemph's drivers are the cheapest major componets of his system . . .

Although the Extremis type woofer would be a better performer than the one used in the Diamond set; it would take a LOT of time, money, and work to design a speaker system that would excel over the Diamond Audio set.  And if you went with the woofer available from Creative Sound Solutions you would probably have to design around a 3-way topology which increases difficulty tenfold.  The question you have to ask yourself is whether you have the means and patience to try it.