A new sound system for the 500-seat sanctuary of The Pentecostals of the Fox Cities in Menasha, WI, presented several challenges. Subwoofers were needed to reinforce frequencies beneath the 90 Hz point to meet a stated design goal of providing a system offering true full-range capabilities.
Finding a location for the subwoofers in this sanctuary proved to be a challenge. Placed on the platform, they would tend to distract the musicians and singers while flooding the area with feedback-inducing LF energy. And the ceiling was far too low to consider flying them.
The platform height would be a tight 24 inches, leaving much less than that to realistically work with, and without proper isolation, the entire space under the platform could tend to act as a “resonation chamber” causing uneven frequency response and feedback.
The solution was a two-chamber box that effectively isolates the low frequency energy from the platform. The dual design of the chamber was necessary to isolate the subwoofers from the platform extension, and then to isolate the extension from the existing platform.
The subwoofer “inner chamber” is constructed of wood and fastened tightly together with glue and screws to prevent rattles and buzzes. All seams are caulked air-tight, furthering isolation properties. The “outer chamber” – built within the airspace between the inner chamber and the platform - is isolated from the platform by using wood and concrete board.