Soundstage and explosive dynamics?

Kosst  I guess I should've said you need big drivers and efficiency. If you have both of those attributes it will deliver in spades. 
 If you don't have the size you need much more than one driver and then generally you lose out in the imaging, staging and coherency department. 
 I say generally because I'm sure there are exceptions to the rule. I just haven't heard them.
  If I were the OP I would look at Tannoy's or Altec 604 Based speakers. 
 Or a pair of altec model 19, voice of the theatres or Valencias. 
 In fact if you look at vintage stuff those attributes are very common. It's only when they started designing speakers with solid-state in mind that we lost our way.  Efficiency was down, they started trying to make smaller boxes  with wife acceptance factor in mind  and then we ended up with more polite sounding speakers.  
You can't cheat physics...

madavid0 --

I’d be looking for used and active ATC speakers, like the SCM50, 100 or, if within economical reach and space permits, the SCM150(ASL). Or, how about Volti Audio’s Rival (recently very favorably reviewed in Stereophile), or a used pair of its sibling, the all-horn Volti Audio Vittora’s (may be too expensive)? From the same company is also the Alura model, which should also be had within your budgetary requirements as a used pair.

In continuation of poster @analogluvr’s views and his fine recommendations, I’d stress: If you want to experience the full(er) envelope and macro-dynamic wallop be sure not to buy speakers too small or too inefficient; there’s really no replacement for displacement, as a saying goes, and all the named (and very efficient) Volti models should fit the bill here with their 15" bass units and powerful BMS mids compression driver, as should the larger ATC models already mentioned. Excellent micro-dynamics are especially to be found, I believe, with horn-loaded speakers, but even though the ATC’s are not horn-loaded I’m sure they’ll perform admirably in this regard as well (the 3" midrange "super" dome used here is a true powerhouse).

If you can get volti in your budget jump on it!  Amazing speakers. 

The Volti Rival falls within his budget and was recommended earlier. I agree that the Volti speakers are very nice.

Huge soundstage and explosive dynamics? -The Proac Response D48r defently have it big time .