is where you really need to go with this question. Do a search for pioneer B20. They are a step up from the ratshack crap that have many devoted, delusional fans in the cheap/cheerful crowd that lurks there. Look up "Godzilla's" speaker project.
Not that they "don't sound good". They are OK. But in using CHEAP,taiwan drivers, don't lose sight of the fact that you are deliberately choosing to build a compromised system...don't expect high end results with a low end investment, life and physics do not work that way.
Hey, why not just build something from a PROVEN design, like the 1 Pi's?
That said, I would not part with my B20 TQWT speakers for less than $750 under any circumstances, but YMMV.single driver web site
http://www.melhuish.org/audio
I'm not "the hall monitor", in spite of what a few individuals might think...but KNOCK OFF THE DOUBLE POSTS. Search the single driver website. Everything you need to know, INCLUDING THE CORRECT T/S data, is there. Good luck. Sam