Tuesday, July 13, 2004
Romney area residents Joe Crawford and Larry Brown
met at the Bottling Works today to add some extra baffles and
run some sound tests.
As Larry explains, "Taking a large warehouse
space and making it suitable for music is more complex than simply
filling the space with stuffy material that absorbs sound. Different
materials absorb different kinds and different amounts of sound.
Our task was to figure out precisely how much and what kind of
absorptive material to use and then where and how to install it.
Our approach was to remove the objectionable reverberating sounds
gradually. In this way, we could mold the sound characteristics
of the space by adding different kinds of absorptive acoustic
materials then run sound tests and add more specific material
as needed. We knew we could not transform this warehouse space
into a concert hall, but we wanted to get as much as we could
out of the space, acoustically speaking. "
Larry prepared each corner area prior to installing
an additional baffle. First he moved the AWPD (read further for
an explanation of this device).
Then he climbed to up to the ceiling to clear
away extraneous materials .
A commercially purchased baffle was ready to hang.
The next picture shows a close-up view of the textures
on the commercial baffle and the Joe-and-Larry devised AWPD.
Larry continues, "We used three different
materials to absorb sound. Carpet for high frequencies, open cell
melamine hanging foam baffles for mid range sound and thick compressed
fiberglass insulation for low frequency sound. Our greatest challenge
was reducing low frequencies, which are hard to control in a large
warehouse. My technical advisor, Joe Crawford (Stony Mountain
Recording Studio), gave me the technical criteria needed to solve
the problem and I set out to invent a suitable fixture. I manufactured
14 tall, hollow, freestanding fixtures with a curved surface,
which I named, “Arched Wave Pattern Diffuser”
or AWPD’s. I then filled them with ever increasing amounts
of fiberglass insulation until we arrived at the sound quality
that we were looking for."
The back view of an AWPD shows the rolls of fiberglass
secured by strips of particle board.
Once the extra baffles were in place, Joe and
Larry set up their sound equipment.
A reference microphone stands on top a table.
Joe's laptop computer shows a three dimensional
graph of the sounds produced when they played a CD.
As Larry asserts, "The project
has been a very satisfying sonic adventure and should provide
suitable acoustics for musical events far into the future."