[Electriclight]

I would guess you're getting room noise because there is room noise. What kind of room is it? Lots of reflections bouncing around?

Another consideration is mic placement. Typically the mic is right up on the grille at the speaker cone. If you have the mic further away you'll pick up more room noise. A hypercardioid mic would be more directional and perhpas a better choice tha the 57 but it's a classic and you should be able to work with it.