Speakers for leading edge, transients, speed and big sound

That kind of money would get a decent horn-based custom speaker from Deja Vu Audio.  This is a dealer that also builds high efficiency speakers utilizing a mix of new and vintage parts.  The better systems utilize horn compression drivers from the 1920’s through the 1960’s and horns from the same period.  Woofers are either vintage or custom new woofers specifically made for Deja Vu Audio.  At this price level, it is worth a trip to the Washington DC area to hear some of these systems.  You will also find that they make terrific tube linestages, amps and DACs too.

I heard, and liked the Moab.  It is a well balanced system with decent dynamics at modest listening levels (the real test of dynamic capability is how lively the speaker sounds at low levels0.  The JBL K2 is very dynamic sounding and is very good, although not as full and rich sounding as I personally like.  Klipsch speakers are decent, but, modern horn compression drivers and modern horns are not as good as the very best vintage ones, with the exception of some ultra expensive drivers from companies like G.I.P. and Goto (single drivers can blow this budget).  Avantgarde Uno or Duo are quite dynamic, but the bass is not that well integrated with the rest of the sound; still it is a good candidate for a used system.

Charney Companion with the AER driver option is a terrific choice.  Songer makes a fieldcoil driver system that is also very dynamic and big sounding.  The Fyne F1 coaxial driver system also might be a candidate.