Trust YOUR ears... grasshopper. As mentioned above, listen to acoustic, not electric, musical instruments and then try to find speakers that closely reproduce those sounds. Drums, cymbals, guitar, piano, violins, etc, are key, somewhat depending on what kind of music you listen to. Horns, of course, are also important, but like vocals, can suffer more from recording imperfections, than actual limitations in the equipment. Listen...it's all good!!!
Sonny
Sonny