Acoustics Committee

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."