Dear SUNN -
I must confess I'm not familiar with the modular aspects of the Black Widow^r drivers. While a navy musician I just hated the way those heads and cabinets sounded (to the point I took my personal gear to the gigs, even on road trips). Why would a LF driver be modular? Guess I need education on this point.
As far as a decent-sounding low-cost 15, I like the Carvin PS15C. They cost about a hundred bucks, have fun with 200W RMS, and are available in either 4- or 8-ohms. I like the way they sound better than D140F's, but they're not as efficient. My favorite bass speakers are the Electrovoice BX series; if I ever win the lottery I'll get some!
Guess I shouldn't be so hard on Peavey. They occupy an important place in the market. Who cares how good an amp sounds if you can't hear it? I must admit the P has amplitude. It's just that they sound like someone playing a cat with a saw. Rocketboy