A poor recording will always remain as such. What you get with a better balanced system is that even a poor recording would have a meaning. No it will not sound good but it would be easier to follow.
Can a great system make a mediocre recording sound good?
I spend a lot of time searching for well produced recordings as they (of course) sound so good on my system (Hegel 160 + Linn Majik 140 speakers). I can't tolerate poor sounding recordings - regardless of the quality of the performance itself. I was at a high end audio store yesterday and the sales person took the position that a really high-end system can make even mediocre recordings sound good. Agree?