The most dynamic speaker you've heard...

Dynamic & loud are not equal. The K-horns are probably close to both. It doesn't have to be a horn to be dynamic. It is easier for a horn to be loud.

MBL 101.

Low sensitivity offset by endless power handling. When doing shows, MBL pairs up the 101 with monster power amps and cranks 'em to 11. The resultant silent/LOUD macrodynamic impact is IMO startling.

Marty

Maybe mbl 111e.

Or maybe a custom Goto horn system I heard a few years back at Capital Audiofest.

But my current OHM F5s are up there as well.

Must state though that for any speaker to be truly dynamic, one must have the right amp and gear behind it. Speakers are capable of certain dynamics but it is the source material and amplification that is needed also to actually realize it.

Of speakers that I have actually auditioned i would recommend in this order:

1) Revel Ultima2 Salon
2) NOLA Baby Grand
3) Wilson Sasha
4) B&W 802D

All excellent