Re: OT: DIY Music Room sound-proofing

["Krispen Hartung" <khartung@cableone.net>]

Several years ago, when I was playing in a very loud power trio in a 
basement of a rented house, I had the challenge of sound proofing the 
rehearsal room - even more so because I had some asshole neighbors who 
didn't like loud rock n' roll.  I had to buy a db meter and do some 
research 
on what the city ordinance requirements were for volume, etc. Inside the 
practice room, I measuring db levels in the range of 100-115db, and 
roughly 
90db when I put the meter a few inches from the glass window that 
separated 
the basement practice room from the neighbors bedroom window.  When I 
finished my project, I had the level immediately outside the window down 
to 
40-60db, and 60db is roughly the level of an air conditioner. From the 
perspective of the neighbors house, it was almost inaudible with other 
competing natural sounds. My neighbors had an air conditioner directly 
across from in their window, so it was a good standard of comparison.

How I did it? I learned that the university library was remodeling and 
discovered that they were tearing out several thousand square feed of 
ceiling, which was made entirely of acoustic tile. This is the standard 
rectangular tiles that we see in most office ceilings.  This stuff 
normally 
sells for $6 a sheet in the US. I got about 200 tiles for free, but had to 
carry them down 3 floors on my back (4 at time), in 100F degree weather! 
Fortunately, the basement practice room was unfinished, and had not sheet 
rock over the ceiling rafters or the wall frames. This was the key to my 
success, because during my research I learned that the key to 
soundproofing 
was in having layers of soundblocking material, followed by a compartment 
of 
air, followed by more soundblocking material. It is the sandwich approach. 
The sound waves hit the first soundblocking/absorbing material, some of 
which make it to the compartment of air and are dispersed more. Then what 
is 
remaining hits the second layer of soundblocking/absorbing material. By 
this 
time, very little gets to the outside.  I basically put acoustic tiles in 
between the ceiling and wall rafters, and then I put another layer of 
acoustic tile nailed to the outside of the rafters, like normal sheet 
rock. 
I did the same thing in the window, but added 6 inches of foam in between 
the acoustic tile.

The results were amazing, almost uncanny. The room was almost too 
soundproofed and sounded very weird.

Kris