Well, just to let you know, eBay had three CD-XC90 units. It had none of the Sony subwoofers you mentioned, D-EJ915.
I believe Crutchfield sells Kappa Perfects. Maybe Reference. Anyway, yeah, I figured they were pretty good. I believe I saw them in a car audio magazine once. That lovely white expanse... so pretty. Ah, there's a ton of them on eBay... BIN for about $120-$160...
Listening to Linkin Park just re-affirmed in my head that a sub is neccesary. I'm not a basshead, but for certain types of music, one needs a solid thump.
Our church has some JBL main speakers, and some Sony monitors. (for the band, not the mixer dude, who's my friend
He said the JBL's are good for about 350 watts, and the Sonys about 200 watts or so. The JBL's have a woofer, midrange, and horn tweeter. I dunno what the Sony's have. Prolly a woofer and tweeter. We had a lock-in there once and took over the sound system. We popped the monitors over on their sides and aimed them out. Their amp has around 700 watts, however, so we had to stop around 1/3 up on the slider. But it was loud... and clear...
(-:Stephonovich