help integrating a musical sub for minimonitors

just picked up a pair of B&W CM1's

never had a stand mounted speaker before and woould like
a fast musical sealed sub to give me a little extra bass
also i would like to reduce the stress on the cm1's so that they
dont have to produce the lowest frequencies so they can concentrate
on the midrange up

my problem is i did not like the B&W sub offerings i heard
i have to drive quite far to hear a rel sub mated with the cm1's
and i won't have time to do that for a few weeks

i am not really a newbie but i have never had a sub hooked up
to my system nor have i ever had an av receiver

my system consists of an amp and a preamp

from what i read i think i need a sub with high pass and low
pass connections to provide the lowest frequencies and to relieve
my minimonitors from low bass and midbass duty?? am i right ??

how would i hook this type of sub up tp my preamp as i only
have one set of unbalanced connections
although i do have a tape monitor connection if that helps
but no subwoofer out or bass managemant capabilities or even
tone controls on my preamp
i only have one set of left and right outputs on my amp also

can this be done effectively?????

thanks for any help or suggestions
I'm not sure I follow what you mean on how the connection will be made. You can always use a "Y" adapter if need be. Cardas makes a nice one. I think the Paradigm ultracube might be just what you are looking for 800 bucks new or so. A little 8" that is almost a rip off of the sunfire subs. Little tiny cube with a massive power amp. But, I did like the sound. Very quick, and one of the few I would consider owning with a pair of monitors.
I am happy with my ACI Force,750.00 Check out thier website for the hookup info you asked.
I have a small secondary system consisting of Von Schweikert VR-1s, and a Creek 5350 SE. I added an REL Q108E. It has a Neutrik plug with speaker line level inputs. The wires connect directly from the speaker terminals on the back of the amp to the Neutrik plug on the sub. It is simple and I really appreciate the bottom end below 50 Hz. It blends well with my monitors. Good luck.
The ACI Force is a good bet, but ACI doesn't recommend the built-in high pass, suggesting instead you use their dedicated high-pass filters. You would then have to use a Y adapter (ACI sells these too). I suggest you also experiment with plugging the CM-1's reflex port for better blending with the sub.