Speakers with deep base

Legacy Focus 20/20 or Focus HD (earlier versions had loose bottom end IMO -- 20/20 and HD versions corrected this). Big sound with abundant bass and good musicality -- very dynamic (both need strong solid state amp to control the woofs--pair with a good tube preamp and this is wonderful rig).

Slightly used Legacy Focus meet your requirements. Either two or three 12" woofers per speaker. (The older models have three per speaker, the newer ones two.) 95db/2.83v efficiency, so your watts go a long way. I don't know of any other speaker that moves as much air for the price, without a dedicated subwoofer. Pretty good sound overall.

Vandersteen 5A will perform true 20 hz bass in your room
They feature a self powered double cone metal 12 in a sealed enclosure with a unique tuning feature that will optimize the quality of the bass in your room this enables the mid bass,patented mid-range, and treble drivers to sit on a bass coherent foundation allowing you quality performance and coherence at all volumes.
Johnnyr

K-horns?Good luck,nice problem,Bob