Accoustic Reflections

Ian Rusconi (on behalf of the LCA)

It's been a pleasure to hear all the positivity surrounding the acoustic refit at our community hall. My heartfelt thanks go out to the LCA for their willingness to undertake such a huge project, to the army of volunteers who contributed their blood, sweat, and precious time to assembling and installing the heavy panels on the walls and ceiling, and to the organizers of the Baffled Festival for celebrating so many expressions of sound.

Early last year, I took a set of acoustic measurements in the hall before the old murals were removed, using both amplified tests (sine wave sweeps, targeted frequency analysis, broadband noise reflectivity) and unamplified impulse response recordings. I recently had the opportunity to take new measurements and create a before-and-after comparison of the improvements. As I'm sure many of you already know based on your experience in the room, the results are excellent. Anyone who wishes to delve into the numbers is welcome to contact me at ian.rusconi@gmail.com to set up a nerd session.

For the rest of us: without getting too technical, the room's natural reverb has been dramatically reduced, from nearly 4.5 seconds to less than 1 second. Anyone inclined to hear for themselves can visit tinyurl.com/LasquetiHallReverb to hear a "balloon test" – two recordings of popping identical balloons in the center of the hall, made with the same device in the same location, played back to back. The first was taken early last year with the old murals, and the second was taken at the end of this August with the new configuration in place.

Also captured in the first recording, you may notice a lingering overring after the initial sound, which is not present at all in the second recording. That "standing wave" (a natural amplification of a specific frequency based on the proportions of a space) and many others have been eliminated by the design and placement of the new sound absorbers. This type of cleanup has made the community hall a much more acoustically neutral environment, where room mode interference is drastically reduced and sound waves propagate without negative distortion.

Put simply: it sounds natural in there. In my mind, having successfully addressed "the sound of the room" marks the completion of Phase One of our acoustic improvements.

For Phase Two, I firmly believe that we should address the equipment available for performances. The most recent audio equipment improvement was the acquisition of powered subwoofers, which made an enormous difference in our ability to produce quality performances both indoors and on the outside stage, but our "main" speakers are significantly underpowered for both applications – they have been pushed so hard for so long that half of them are currently inoperable and awaiting repair. Even with all of them functioning, we cannot put on our beloved summer festivals or other large shows without renting more powerful speakers and larger mixing boards. Our mic stands are damaged and tired and our supply of audio cables is dwindling; these resources are routinely supplemented by individuals with their own private equipment just so we can put on the shows we all love.

I'd like to encourage anyone who wants to see our community hall operate as a truly self-contained performance venue to contact me to discuss potential solutions, and to please consider making a targeted donation to the LCA for sound system improvements.

I hope you all enjoy the shows. I know I do. 


Your happy audio engineer,
Ian