My friend and I want to build a new studio in which we can both record and play with our bands. Whe have a little warehouse of 56 meters and an height of 3.78 meters.
We want to breate a box in a box to limitate the ammount of Db, but when we requested the price for the job a local society ask us more than 30000 €, too much money for us !!!

So, can you tell us the best way to realize this job ourselves?
I also have a little drawing of the basement, I hope it will help!
http://img524.imageshack.us/img524/6100/piantaev1.jpg
I'm sorry, it's in Italian, but I'm sure you'll understand!