Speakers must be chosen for a specific room...
Also adapted to a specific amplifier...
Not for a genre of music why?
Because timbre, dynamic, imaging soundstage, listener envelopement and all other acoustic factors emerge from the speakers/room relation...
Then when listening to violins any good speakers/room relation will do the job...
For sure you can own small speakers and listen to near field in a very small room but even there it is the speakers/room relation which will give you an optimal timbre instrument experience...Not the brand name of the speaker by itself...
There is plenty of choice in speakers design for example and to answer your inquiry i will look myself about the small Harbeth which are supposed to be good for mid range especially... But his relation to your room will be decisive for sure in my experience...Room acoustic play a role even in near listening in very small room especially...But there is too much possibilities to recommend ONLY ONE speaker not knowing your room especially...
There is no speakers specialized in violin quartet though ....
my best to you....
This is my favorite haydn interpretation... Tacet sound is magical....