Re: slightly OT, soundproofing

Lumpy wrote:

Robert Riddle wrote:

Well, I need a space free of outside noise and to keep the inside
noise from getting out. Now, I realize in a standard home this is
pretty much impossible; noise is going to escape/get in. But I can at
least minimize the effects, IE, keep the bass notes from rattling the
ceiling above and footsteps from vibrating through the floor into the
room below. And I'm hoping to do this without tearing up walls and
losing all chance of getting my security deposit back lol. Again,
this is a nice, windowless, completely enclosed room. So I'm hoping
this shouldn't be too difficult.

It WILL be that difficult. Ever hear a kid at the traffic light
with a booming stereo? Bass frequencies travel through
most objects. Particularly through objects that houses and
buildings are made of. You will NOT be able to minimize
the bass frequencies that LEAVE your room.

The house two doors down used to be a "band house." They played in the basement, hung heavy carpet everywhere, including the ceiling. I still knew the bass line to every song they played! ...vintage SVT.

You MAY be able to tune the room so that you, inside
the room, have less boominess. But that's because you're
causing the sound waves inside the room to cancel each
other. The sound waves that travel outside your room
continue outward. And when they reach other building
materials, they can resonate those objects and make
it seem even louder outside than inside.

Your room is essentially the inside of a speaker cabinet.
All six surfaces vibrate in harmony with the sounds you
create. That vibration occurs dispite any wall treatment.
The purpose of the wall treatment is to dampen the sound
waves that are reflecting back and forth between your
interior walls. The sound LEAVING the room has already
left. No wall treatment will affect that.

I'm not trying to be discouraging just for the sake
of discouraging. But you can easily sink thousands
of dollars into a room and achieve a zero or even
worse than zero effect.

Start with a spectrograph analysis of your room. That's
not a giant challenge. You download some spectrograph
software, run the program etc. Those programs typically
have a reliance on a visual display so we'll have to
figure out a way for you to interpret the results.
But there's nothing difficult about the measurements.
The auralex site has a free applet that will do it
based on the simple measurements of your room. It
doesn't actually measure the frequencies in the room,
obviously. But you enter the dimensions, floor and
wall covering materials etc, and it tells you the
recommendations for any kind of treatment, their
brand or anyone elses.

Recording studios typically start with a relatively
hard surfaced room. Hard floors, hard walls etc. They
then put portable panels in measured spots to alter
the standing waves.

BUT - The big picture, short answer is, you cannot stop
your sound from getting out, nor outside sounds from getting
in, without significantly expensive remodeling.

My suggestion is that he rent rehearsal space.


In Your Ears for 40 Years