Getting good sound quality below 200Hz

My system is multiamped and crossed over with boxcar digital filters. By happy coincidence it crosses from bass to mid at 190hz, and I can shut off the mid/high power amps and just listen to what’s below 190hz, which I do on occasion to be sure channelization is intact on the computer’s soundcard driver before I subject the mid/hi horns to possible damage. I don’t have bass horns, but I do have a pair of Altec 421a 15"ers that are as clean and fast as any woofer, and it sounds like mud. Absolutely all definition and location (aka harmonics) from any bass instrument, even a pipe organ, comes out of the horns. With everything on the bass sounds fabulously crisp.

The room has a ton to do with bass under 200hz. Is your room small or square? 

When I hear about slow, sloppy, undefined bass, it is usually a room with a long decay time and ringing. 

It’s the fact that you have these bass drivers in open baffles. That turns their radiation pattern into dipole (radiating to the front and back more or less equally), and that tends to rob the bass of impact unless compensated for in various ways.

I remember reading reviews of Legacy Audio’s then TOTL speakers which were open baffles with 2 x 12" drivers at the bottom of each speaker. The bass was typically described as nuanced and delicate, but not up to dance party standards. A case where the speakers looked like they would shake the foundation but could not, because of the open baffle & dipole radiation pattern...