I too was searching for a natural sounding speaker. I wrote a review of 15 different speakers I home demoed. I ended up with Boenicke speakers. The designer seems to spend much time recording concerts and as far as I understand it always aims to create a speaker to reproduce the sound of a live acoustic instrument. The other most natural sounding speaker I came across was the Sonus Faber. Review here:
https://forum.audiogon.com/discussions/a-brief-review-of-15-high-end-speakers-on-home-demo-including...
https://forum.audiogon.com/discussions/a-brief-review-of-15-high-end-speakers-on-home-demo-including...