The objectivist has internal belief system that regulates audio equipment evaluations, It doesn't matter that nearly every audio system is bespoke, likely totally unique assemblage of equipment, room, ears/brain etc. I accept I can't know the quality of sound others experience with all these variables in play. I accept at face value they hear what they hear. The internal skeptic in me remains, but I have capability of open mindedness, I can be convinced with new knowledge. Bottom line for me, why should I feel the need to impart my sound quality evaluations to another, I respect their evaluations as credible for them.
As other posters mentioned, a quality system for me is one that involves me emotionally. Sense/illlusion of performers in room has been my goal from the very beginning.