You're right to be judging sonic qualities by listening to acoustic music. Large-scale classical, chamber, quartets, jazz can present proper tonal qualities, dynamics, and nuances not found in electric or amplified music. I listen to mainly classical music and also attend live concerts which helps confirm realistic sound from my home system.
But you need to audition different types of cables and components to know what is possible in sound reproduction. Regarding cables; speaker, interconnects, and power cables will influence sonics. There are online dealers who offer 30 or 60 day return policies allowing you to audition cables.