Fostex FW405N

hi guys,
I have recently received a pair of FOSTEX FW 405N that I ordered to make a 2 way spkr for my father, the high section is made from a jbl 2426j with homemade horn, and the crosing frequency is approximatively 900HZ, We used to run that system with a JBL 2226h that was more effiscient than the Fostex, but had no low end at all...that is why I tryed the FOSTEX...
my personnal opinion on the fostex is as follow:
excellent linearity, and no critical cone break, easy to cross over and a real deep low end(lowest than a JBL 2234 or 2235) but really low efficiency almost 91db when used passively with a cross over and no kicks A**s character of the JBL's even played very loud it doesn't show high pressure right on the chest...

I would really appreciate to have your opinions on this speaker as I am quite dubitative, I loved it fopr the first listenings(for the deep end) but now I think it lacks a bit of punch)
any opinion?