What traditional dynamic speakers deliver a sonic signature similar to a horn speaker?

Horn-based systems are the best at delivering the goods at low volume levels (which explains why they are popular with apartment dwelling Japanese audiophiles even though they take up a lot of valuable space).  But, really good horn systems are very expensive.  Some, which I find to be a bit more troubled by ‘megaphone” coloration, like Klipsch Cornwalls, are not that pricey and are worth checking out.

I also like some systems using wide-range cone drivers in quarterwave back-loaded horn cabinets, such as Charney Audio speakers and certain Voxativ speakers (like the Ampeggio) and Rethm speaker (back loaded horns with self-powered subwoofers) are also quite dynamic at lower volume levels.
More conventional speakers that are good at modest levels include Audio Note speakers and some ProAc models.

+1 for the Charney Audio horns. Why not just buy a horn speaker instead of looking for the "horn sound" in a conventional box design. Charney has a number of designs to fit budget and room size. I have a pair and have no desire to look at anything else.
Good luck,Chris
http://charneyaudio.com/

How about Volti… the Razz for example. 

I recently bought a pair of the Volti Razz's. They replaced a pair of Tekton Perfect Set 2-10's which were my 3rd pair of Tekton's. The Razz's are far superior to the Tektons in every way. No regrets here. Good luck. 

“ If you like the horn sound, why not just get horns? Too big for the room (or the little lady ;-) ? “

Or get a pair of Heresy....   for some reason females don’t mind their looks.   Which is funny of course because they take up the same real estate on the floor as my Forte or any of the Zu.

I can not speak to the Razz but I have heard other Volti and they were awesome ... the Razz is their smallest but it is still what most would consider a large speaker.