15k USD Speakers for Classical and Pop Extended Listening, Near setup, Low volume

I have ATC SCM40’s in an arrangement not totally different from what you have, including a large reflective coffee table in front of my sofa. The key aspect of the ATC’s is that they are very essy to place in rooms to get optimal imaging. They do play loud very well but that midrange driver gives plenty of life at low volumes. I like listening to them at modest listening levels as well. The reflective surface doesn’t affect the sound much, the spatial information in my system is as good as I have heard anywhere.

The ATC’s are very modestly priced now, I recommend them highly.

Sound Labs 545'

Low volume listening favors high efficiency drivers.

Check the newest Tocaro 48. Its a 15" full range driver. Magic. The 40 would work well too.
If you are into music but not into hifi, checkout Tocaro (and Crimson)

Wow! Nice size room for an office. I am a biased Maggie fan. So this will come as no surprise. The LRS + set and a Rel 8” sub will get you the biggest soundstage and dynamics at anywhere near its price point. That would open up your budget for electronic devices such as streamer/phono, DAC (if digital) and a high powered high current amp. Just my two cents. 

Sonus faber Maxima Amator. Right in your price range and ticks all your sound quality/characteristic boxes.