New Kent Elementary School Gymnasium Acoustics

Gymnasiums are actually fairly easy to treat in terms of the mathematics involved. To calculate the absorption required, it’s a simple relationship between the volume of the room and the reverberation time. Since a gym is typically a flat, rectangular box, there are not a lot of variables in the equation. The trick is to evenly space out the acoustic material as much as possible. In a gym, materials need to be up out of the way to reduce incidental damage from balls and things. Here, to keep costs to a minimum, we went with 2″ thick AlphaSorb® PVC Plastic Acoustic Sound Baffles in the ceiling. They easily suspend using steel rope attached to trusses with beam clamps. For the walls, we chose AlphaSorb® Fabric Wrapped Acoustic Panels in a 2″ thickness at specified intervals.

The New Kent Elementary School’s predicted result in reverberation time after treatment was 1.5 seconds. The Reverb Test (RT60) conducted after treatment was at 1.46 seconds, below expected. We couldn’t ask for a better result. The PA system is now very intelligible. The teachers and educators are better able to communicate instructions to students, without having to shout. The benefit is a calmer and more pleasant environment for the students. At the end of the day, the usage of the space dictates the desired RT60. Case in point, a gymnasium is not a recording studio or a video teleconferencing room. There is no need to turn this space into a “Padded Room," so to speak. Having said that, there is research in place showing that 1.5 seconds is, in fact, the optimal RT60 for speech intelligibility for gymnasiums, so it should be the benchmark that folks shoot for when budgeting these projects. The takeaway is that treating spaces like this is not a guessing game, but a very engineered approach that gets it right on the first try without spending too much in over-engineering it.