Mana Soundbases

I have just moved to London and after a great deal of experimenting I can't seem to get rid of booming, bloated uncontrolled bass. I am not pleased at all. I know this can be attributed to speaker placement, but in this case they are well away from the back and sidewalls and I have fussed with them extensively to little avail. I understand that London's flooring is not the best for audiophile applications and it is clear even from hitting the floor that it vibrates extensively. I was thinking about trying Mana under the speakers to get them off the floor. I was also considering granite. I would be curious to hear anyone's thoughts on either solution or both?

thanks in advance.