Can a great system make a mediocre recording sound good?

Hello lcs01.You can tell by the many responses - Great Question! By "a great system" I think you mean a system that reveals ALL of what the recording engineers give us. This is a dangerous as seeing a new girl friend without her makeup and supportive clothng. I have some recordings made "in the field" under less than ideal circumstances. It's the only way I can hear this music, so I can ignore the "sound" and enjoy the rhythm, instruments, and voices. A good system tells the truth and the truth is not always pretty. A friend of mine brought over some of his favorite music and was horrified to hear how it sounded on my system! It's not his favorite music anymore. But he could have kept it and just listened to it at home - it's how we feel about what we hear that matters. Some people talk about "forgiving" speakers. Maybe "everything" is not what they want to hear. Some folks want to hear the sneeze in the back row of the audience X number of minutes and seconds of a particular recording; or a dropped mute by a clumsy trumpet player. I just want to hear the music.

I'd never want a system that could only sound great with the best recordings. To that end I've always voiced my systems to sound GOOD with mediocre recordings since this is where the vast majority of music resides. As I and others have mentioned, get the timbre, tonality right and  mediocre recordings can be involving, great recording simply follow along and become even more involving.

Mostly, I want my system to be musical, certainly I seek maximum resolution but not at the price of musical, I do believe these are not mutually exclusive goals.

a great system is a system that plays the music the owner likes to listen to beautifully... where different recordings have different qualities, it is up to the owner to construct the system to handle the range of variation ... numerous ways to meet this challenge... here is one...

A great system makes good recordings, sound amazing. Listening to anything not meeting that standard, will be played once and put back in its case. never to be heard again. 

Why is that? The Greatest performances can be on poor recordings. 

It’s true that a better system can make even the most poorly recorded, mixed, pressed album sound better, but it’s still not going to sound really good, only better.

JD