best subs i've heard are the sub towers of the infinity irs-v's. i'm sure subs of the $135k genesis top model full-range speaker are similar, as they're a similar design, done by the same guy. next best are the vmps larger subwoofers, and they're an absolute steal at the price. no other that i know of can go as low, play as loud, w/as little distortion as these. and, being passive, they offer the ultimate in flexibility for matching any speakers, allowing ewe to choose yer own amplification & choice of x-over. i tink the fact that they're forward-firing, not down-firing, also helps make them easier match w/monitors. caterham1700, i'd wager that a pair of these w/a marchand xm-9 x-over and a quality s/s amp would allow ewe to seamlessly blend w/*many* different monitors. even full-range ones.
ymmv, doug s.
ps - i've never heard the kinergetics sw800's, but from what i've heard about 'em, these wood be worth checking out. (but only infrequently awailable on the used market). jim, a frequent contributor here, successfully mates 'em w/martin-logan cls', & these are notoriously difficult to mate subs with. and, jim's into alfas, so he *must* know what he's talking about! ;~)
