Subwoofer with Floorstanding Speakers?

I think mofojo said it.  YES.

But integration/location is critical and multiple sealed subs generally get things really right. You'll never know they're there but you'll know when they aren't.  Plenty written on the subject.

illaheman,

I'm using 3 F12's and love them.  Mixed with Legacy Audio Signature III's, 2 channel system in a 16' x 28' x 8' room. Wish I had 14' ceilings though.

I have a pair of "overkill" subs with a pair of floorstanding speakers and was fortunate that, in my new house, my dedicated listening room is much better suited to the integration of the subs with the side speakers, compared to the last house we lived in, where that listening room added it's own bass, regardless of what the bass line in the music was, requiring me to add 10 bass traps to make the integration tolerable.

If you are successful at integrating subs to your room they add a dimension to the musical experience that you'll really enjoy, especially the "visceral" experience.