Soundproof this room.

hey guys. i live in oshawa, ontario, canada. I have a studio, in a condo.. and, i have been upgrading over the years, mostly with gear, and now i want to soundproof, isolate a spare room that i have, so i can track drums, and loud amps, without killing everyone. The Room have 4 walls, that are about 6 inches of concrete, with plaster and paint. the dimensions, are 16 x 12 x 10. I want to do a room within a room constrution. I have done some research, and, i am mostly interested in what to do with the floor. There is a room underneath this room, and i will not be able to pour concrete. What are my options? and, if someone could point me in the right direction for the construction of the walls, etc. I would like to be able to play loudly , in this room at all hours of the day/night. is this possible? how much mass will i need ? anyway, just some help would be great. I hope i have gotten everything. Thanks i can add a pic, if that is needed.

If you can't float a concrete floor/room in your space, you're not gonna get close to enough isolation to track drums - period. Best you could do is make it less obnoxious to the neighbors with a heavy wood platform floating on 3" rockwool, but that'll only improve things by maybe 10-15 dB, and you'll likely need more like 40 or 50 dB minimum. No magic bullets for this one, sorry... Steve