I would say not at all important, with two big caveats: You need to use sorbathane isolation feet under your electronics, especially tube gear and more than especially for your turntable. And if you have floor vibration, you must use a wall mount for the turntable.
All this of course assuming you don't play at an average 98db volume level.
All this of course assuming you don't play at an average 98db volume level.