Beall Concert Hall has new sound diffusion

Nov. 7, 2013—Beall Concert Hall is undergoing a bit of auditory facelift at the moment. Last week, the first sound diffusion panels were added to the upper quarter of Beall’s stage. This is the first step in a four-part acoustic adjustment to the nearly 90-year old hall aimed at softening the harsher tones produced by larger ensembles.

Beall is respected around the world for it acoustic design. However, it was designed for vocalist and smaller ensembles. When larger instrumental groups or groups that require amplification perform in Beall the sound waves build up in pockets above and behind the stage, creating an ear-splitting effect that has been compared to an amplified scythe blade cutting through air.

“Acoustically speaking Beall is not broken—it's totally awesome,” Director of Facilities David Mason said. “Except when we host big bands or anything requiring sound reinforcement like gospel. The trick has been, and will continue to be, keeping what we love and changing what we don't—and the things we have trouble with are things that Beall was not designed to do.”

The sound diffusion panels are designed to break up the trapped sound in those pockets and soften the brighter tones, eliminating the cutting effect. The panels are made out of aluminum and heavy canvas that allows the midrange to pass on through, breaking up and mellowing the highs, and warming the lows.

Tests last year conducted by Kirkegaard Associates (acousticians) found that simply holding a piece of fabric up against the upstage walls had a tremendous and positive effect on the sound quality in the hall for larger ensembles. As a result the sound diffusion panels were listed as the first and easiest acoustic correction to be made. Luckily, it was also the least expensive of the top four fixes.

The next step is to add a curtain in front of the organ loft. Adjustable sound diffusion panels will eventually follow the addition of a curtain on the stage walls, and finally a new sound cloud to replace the current inverted pyramids. Final completion is dependent on available funds.