Audiogon member suggestions for a speaker that sounds good at low volume!!!

I am looking for speaker suggestions (new or used) in the $1000-$4000 range that sound good at low volume (45-50db).  I listen to mostly jazz and classical music late at night while everyone else is sleeping so the volume is low.  My current speakers are Vandy 2CE sigs and they sound good at higher volume levels but I listen most critically, at low volume and hope to do better.  My amp is a Classe CT-2300 with a Classe CP-800 preamp. I have a larger room 20ft X 20ft but seldom listen to music loud. Monitor of floor standing is fine.  

I understand the limitation of human hearing (Fletcher-Munson Curve) and also an appreciation of the synergy of speaker design, speaker placement and room effects.  Anyone out there have a speaker they like at low volume?

Thank you in advance.

Treo or the new carbon tweeter VLR
i listen at low levels at nite in our condo to Treo CT
working your room and system noise floor

I would recommend looking at Harberh and Tannoy speakers. 

On the recommendation for high efficiency speakers, in my experience with Tekton and some expensive horn models, they did not sound good at low volumes - it became all tinny treble. I understand in theory they should work better but that hasn’t been my experience. 

I suggest you  take a look bache002 ,  if you go to Brooklyn to listen and like it 
you can get 2 weeks trial time
In a 20'x20' room, assuming a normal (7'-10' triangle) seating/speaker arrangement, you won't hear much music at 45-50dB, just like elevator background music. I may be the first person to say this, but I wouldn't waste time//money on quality speakers  and get some good headphones instead. If you insist on speakers, I'd suggest stand mounts with a pair of subwoofers.