To be able to practise on acoustic drums at home, I have currently built myself a soundproof room. To optimise the sound dampening effect the project is based upon a "room in a room" construction, whereof the ceiling and the walls are completely separated from the initial room.

The whole construction rests upon a floating floor (30mm Insulation, floor plasterboard, 22mm chipboard) The walls and the ceiling materials are 2"x4" framework, 100mm insulation, 2 layers of plasterboard + 1 layer of fibreboard in between to make a "sound sandwich". In adition some materials for redusing the rooom acoustics is implemented (Chair, foam rubber matresses, pilllows. 1 extra layer of plasterboard is installed in the ceiling to minimize the sound upwards even more.

I'm not an expert, but the construction is based upon various kind of information from norwegian Sintef, sound forums, studiobuilders, and some personal adjustments.

The sound reduction is very satisfying. Almost 90% reduction of the sound outside, and about 80% inside the house. There is no longer a problem to practise on the drumset in the evening :-)

For drummers who have similar projects and might be interested, I've put out some photos of the building process. Please visit the links below: 

Drumroom photos (Photobucket)

Slideshow (Photobucket)

Drumroom photos (Facebook)

 
Frame with air condition system via sound trap

1st layer - Plasterboard

2nd layer - Fibreboard

3rd layer - Plasterboard + 1 layer extra in the ceiling