A set of three 12" Klipsch subwoofers.
2 SW12 IIs (stacked) from the mid 1990's and a recently acquired RW-12D.
For education purposes, the SW12s, were upgraded with high end drivers/radiators from Parts-Express, I stuffed the cabinets with poly-fill and we acquired Anti-Mode 8033S II to augment Audyssey XT. With a downloaded copy of REW, I've been able to dial in the system which measures flat to 20Hz but the system has little if any tactile feel. Sounds great but has pretty much, zero impact bass.
(actually, at this point, by comparison to Rythmik's offerings, these subs are so weak, I'm embarrassed to mention them)
Currently? We have an order in for a pair of FV15HPs. Hopefully we'll receive them middle next week and can experience what you describe.