Opinions wanted: 10-30K Speakers for Jazz/Folk

Rockport Atria II's.  

At the high end of your range, but I think they do really well for what you're after.  I find them to be exceptionally accurate, but without venturing into sounding clinical - more "musical" (admittedly a hard to define term).  Voices come through with warmth, without sounding colored (Joni Mitchell's "Blue" sounds amazing, and IMO it's a hard recording to reproduce well).  Jazz records have a very nice spaciousness and sound stage, with live recordings sounding like they are really live, more than just a live recording ("Ahmad Jamal's Alhambra" is a great example).
https://rockporttechnologies.com/atria-ii/

I have mine paired with a Nagra Classic INT integrated amp.  Extremely happy with the combination. 

ProAc K3 or K6 signatures, they don’t need a ton of power but they will reward good power. 

Me, for what you describe, I like Maggies & Harbeth, both well below your price range, but I’m happy- ymmv

Again, can’t help myself to plug this system.
heard it at one of the audio shows long time ago, his newer incarnation are so much better.

 Check it out, 
www.sanderssoundsystems.com. 
 Speakers, plus a Magtech amp, other stuff, and the warranty, .....best in the business.
you owe it to yourself to at least call and talk to Roger Sanders about his speakers, amps, etc. 

 take 20 min to call him, and speak to him. 
   His system is one of the best money can buy.
you will be rewarded !

 I wish I had your dilemma, I would be on the,phone w Roger immediately to talk. 
 Nothing to lose, everything to gain. 
 His amps are audios best kept secret.    Dad the review about the Magtech amps and those MBL radiostrahler speakers.    

JBL 4343B’s - great for jazz and folk and rock.https://www.youtube.com/watch?v=PqBcW28IYsc
https://www.youtube.com/watch?v=0NiZ2k7GUWE&t=3s
https://www.audiogon.com/listings/lisa69jb-jbl-4343b-speakers
http://jbl43.com/?mode=f3