that will help a bit, because it decouples it from direct contact with the floor. Contact with the floor (solid) is an efficient transmitter of sound.

But frequencies below 80hz are pretty long waves. They might be hearing 40hz stronger than you are getting it.

Put it this way:

I built a 15" sub with a 1000w amp. The low bass in the 20's will rattle your privates from 50 feet away more than it will from 8 feet away.