How do you know when a stereo sounds good?

 This post brings up something I often wonder about. 

Best song title tie in- "What kind of fool..." 

The other question I have is why do you sit down one day

and absolutely love the way your system sounds yet the

next day conclude it is nothing special?

When I dance. Not a good thing.but does prove the stereo is doing its job.

I get your point thanks!

My deepest reespect to you....

@mahgister Of course all that too.  I'm just describing the beginning of what I find enjoyable with a well implemented audio system.

It is like asking "How do you know if/when you are enlightened?" For a Buddhist follower, it is a difficult question to answer other than saying, "You know when you know."

Jokes a side, let me try to answer from my point of view. I know my setup is performing at its very best when it reproduces human voice male/female just like they are in my listening room. For my tastes, stereo sounds great when Ella, Lady Day, Louis Armstrong, Jim Reeves, Lata Mangeshkar, Nana Mouskouri, Luciano Pavarotti, Dame Kiri te Kanawa, and many other artists sounds alive in my room. Of course, there are other measures as well. But recognizing and relating to the voice of your favorite artist should be something most everyone can do.

This should not require any special training or skill such as hitting the race track and getting used to driving a Porsche! Some actually require such training as they do driving a Porsche. They are bit handicapped with driving disabilities. But most folks should be able to recognize and enjoy the voices of their favorite artist from their stereo set up. Hope this helps.

Any system i ever listened to was sounding good to at least ONE person or listener, the owner with or without my favorable opinion...

This is common place observation...

But reading the answers it seems nobody  had realized that almost all answers ONLY repeated an instance of this common place fact... Then these answers could never  said anything valuable about an objective criterion which anyway CANNOT and could not be "gear with good measurements"...Or the pricier gear....All gear at any price or  quality levels, NEED acoustic control and treatment at the end anyway....

The OBJECTIVE way to produce an answer is then by listening experiments in your own room with ACOUSTIC principles... Play with them.... COST=zero

Upgrading, even if the "upgrade " affected really positively some aspects of the sound experience, upgrading COULD NEVER rival or compensate for the impact of a negative or positive acoustic room settings...