Well, ya have to do something besides cleaning at 4AM and this morning I went looking for something entirely different. Those 70 watts are calling me...A 3. 25 cu ft ported box, according to WinIsd with these drivers crossed at 3500Hz:
Usher woofer
Usher tweeter
Been thinking for some time about how mainstream audio uses long excursion/low efficiency woofers to get below 30 hz wihtout breaking a sweat so my interest in building this, with a 4th order L-W crossover is real.