Soundstage and explosive dynamics?

Kosst you say "at the cost of focussed dispersion".    I find it odd that you regard that as a negative. I myself and plenty of others that I know regard that as one of the positives of a horn. That way you get less unwanted room interactions.   Definitely not good for entertaining though as the sweet spot is small. Anyhow I understand  that you're saying you don't like horn's and I'm completely fine with that, to each their own. It's just when you're saying things that are blatantly false that I feel the need to set the record straight. 

@analogluvr
A lot of listeners and designers consider confined dispersion a characteristic to be overcome. I site modern Maggie’s, Quads, and the Magico S3 as examples of excellent imaging and broads dispersion. It’s also a characteristic of my Focals which image very nicely.
@david_ten
I wouldn’t be at all surprised to find a carefully designed horn exhibiting better dispersion than Tektons. Those giant tweeter arrays Eric likes are directional according to the size of the array, not the individual drivers. It’s very easy to make a useful horn much smaller than that.

For explosive dynamics you need a large speaker with the following specs:
1-dual 15" woofers, at the minimum.
2-at least a 2" compression driver for the highs
3-high efficiency ion less than 96 dB
4-all the above plus bi-amplification, with a bi-amplifie large system you have a good chance of reaching your goal of explosive dynamics.
I have one such system, it is JBL 4350, a four way bi-amplified monster.
I mainly listen to classical, these JBL's can do justice to uncompressed orchestral recording like no other speaker with a very transparent full range sound.

I can recommend tekton impact monitor and the new technics monitor reviewed by Herb Reichert.

Vahes, you forgot an absolutely massive listening space and you'll get maybe so-so imaging, which the OP stipulated.