Great detail, refinement, mid-price office system?

I am looking to improve resolution, detail, tone in an average sized-office 14 X 14 X 10 feet where only classical, mostly chamber music will be played at low to moderate volumes. Current system is Proac Response 1s, Onix integrated amp OA21s, 50 WPC. Jolida JD100A Stage 1 mod (Underwood) and where restrictions of space for components is 12" depth.
Current system is OK, but would like more detail and transparency, particularly for chamber music and also piano and female vocals.
Suggestions for improvement, please, where budget limit is $2K per component, used.