The midi range, not the tweeter, is the most important driver in a speaker.

Yes and no for my speakers. The mid driver, 8” Seas Excel, covers 4 octaves, the tweeters, Seas Millenium, covers 4 octaves. I can’t hear the last one🤭.

Woofers have the first 2 octaves. Crossover at 92hz, and 1440hz. Crossover causes NO issues with amplifiers. Active crossover is between preamp and amps. Amplifier load is just the driver. 
To make K....t happy, no backwave to contain. Open baffles. Bass cancellation? No. Flat to about 24 in my room. Great energy in the all important power range. 
I built these in 2006. Designed in 2004 by the brilliant Seigfried Linkwitz. Orion 3.4. 
No mdf. Hardwood and Appleply. 
Check Out https://www.linkwitzlab.com/  For a tutorial on psychoacoustics, room interface and more. 
No room treatments needed with proper sound dispersion. 
Mic drop.

J. Gordon Holt said it first and best:

"If the midrange isn't right then nothing else matters."

You tell 'em Gordo.  RIP.

The most important frequency to measure is 1842 Hz.  
Get that one right, and the rest will be fine.

A great year!