pcc,
one small correction - i *don't* own m-l's - i strongly considered the cls' but even m-l sez they will max out at 93db, even when crossed-over to subs at 100hz, which is too high a x-over point anyway, imho... while i'd be happy w/the cls' output most of the time, there are times when i wanna be able to *crank* it. thus, my next speaker purchase will prolly be the newform research nhb645's.
while i still feel the marchand xm-9, w/its 24db/octave x-over slopes & wolume pot for the x-over point as well as the low & hi-pass wolume pots, will be more than flexible enuff to mate w/m-l's, ewe may wanna consider marchand's 48db/octave x-overs...personally, i don't tink it's needed, as the vmps' are plenty tight & fast.
oh yes, while i *am* a cheepskate & got most of my equipment either used or on close-out, the subs & x-over *were* purchased brand-gnu (w/a discount, of course!) - still the best walue, even when compared to the competition at used prices! :>) the *only* sub set-up i've ever heard that equals the vmps subs were the sub towers (six 12" servo drivers/side) of the infinity irs series - now equivalent to the top-line $135k genesis speakers.
regards, doug
ps - running a pair of subs, besides allowing for more optimum placement for soundstaging & room interaction, also has the added benefit of allowing the same db-level w/even *less* thd...