what is good sound ?

when evaluating stereo systems, should the performance of the stereo system itself be the reference point, or should the listener be the basis for the evaluation ?

if the instrinsic quality of sound is the basis for judgment, then such concepts as transparency, neutrality or accuracy might be the standard for evaluation.

otherwise, the listener would be the sole judge and whatever criterion, be it based upon sonic considerations or physiological/psychological states, would be the deciding factor.

whatever approach is selected, what is the justification for either one ?