What you can say about lowbass and midbass perfomance for high end loudspeakers ?

But smaller diameter woofers never get bottom low base compare to
big 10-12woofers., the reason a lot a top end designers still make
loudspeakers with big size woofers

Actually more important the cone moving mass , in pro line the using 
big size cone  like Eminence Omega Pro 15A  15" driver with 94 gram.
Some 8" woofer is using in High End get same cone weight. This is 
reason we always like good punch in club , in Pro audio. Nobody
care about listen double bass . I  think is the reason why a huge
amount of folk like Tektone. the using 10" Pro line drivers with low
moving mass and get good punch

I agree,,  except one thing, like i say before,  To get  low  bass like 
30 -40 Hz using Omega Pro 15" woofer you need box very  big 5-6 
Cubic Feet . You can listen nice bass with smaller enclosure , but
never get really low bass 

I start  my discussion with my feedback Egglestone work.
They do split bass job and achieve nice midbass -punch bass. 
Low bass also very good except one small issue. not enough control
bass is boomy in low octave . Why ?  My explanation is - they use
110 Hz  crossover point, to get this , they need to use a very huge
 coil  about 15 mh.  or more .  this coil get big resistance 0.5-0.8 ohm
100 times more them expensive speakers wire. The active low woofer
Module (subwoofer) is the good idea, But some company in marketing
purposes don t want to do this.