Best High Efficiency Speakers for full bass tone

Perhaps something like the Coincident Technology Total Victory V might work? I also wouldn't rule out trying a pair of high quality subs at some point. It's pretty amazing what they can add to most systems, and the newer DSP hardware/software available these days makes integration much less of a problem than it used to be. Best of luck.

K-Horns if you have the corners. If not, KLF-30's (if you can find them) are great. I use them as fronts in my HT in a very large room but they do a fine job for 2 channel with an upscale amp.

I used to live in a loft apt, the area where my speakers were was about 1100 sq ft with high ceilings. My DeVore Gibbon 8's (the original series not the super) had tons of bass. I did use placement and the concrete floor/wall to my advantage. Building material of the internal surfaces plays a big part.

Tannoy prestige line
the higher up the $$ food chain you go, the more effecient the speaker.

READ THE REVIEW: the top two: TANNOY KINGDOM ROYALS AND WESTMINSTER SEs in Positive Feedback review issue #64

http://www.positive-feedback.com/Issue64/tannoy_royal.htm

I've heard them and also many of the lower models in the PRESTIGE line ... in a word for all : STUNNING.

["Looking for something with better bass detail than a pair of extra subs rumbling 60 hz and under."]

I have a pair of Velodyne DD12+ that are extremely detailed, in fact I can't even tell if they're turned on until I turn them off. Or, with the push of a button on their remote, they can thump a kick drum to live levels and beyond all the live long day.

I'm guessing you need to hear a modern subwoofer system properly set up. But hey, good luck with your search.