Overture Center for the Arts: Acoustics

Kirkegard and Associates of Chicago, considered by many to be the foremost acousticians in the United States, designed the acoustics of Overture Hall.   

The only soft or non reflective surfaces in the hall are the carpeting on the aisle, the seat fabric, and the audience when the hall is occupied. All the hard surfaces are angled or broken up to allow as much diffuse reflection of sound as possible. The hall is very live, but there are no hard parallel surfaces to create coherent sound waves or resonate frequencies. The balcony fronts are curved and angled to send sound back to the main floor and orchestra. The room is very resonant yet controlled. 

The visible ceiling is acoustically transparent, and a quarter of the volume of the room is above the ceiling. There are three large curved sound reflectors above the ceiling, each made of 6” thick solid plaster. The first is above the orchestra pit/stage extension and reflects sound back to the performers to help them hear themselves. The second is further out into the hall above the main floor and designed to reflect sound back down to the audience in the first level of seating. The third is further back and designed to reflect sound into the balcony. 

The other feature of the space above the ceiling is the six sets of curtains that can either be exposed, or retracted into closed boxes to help acoustically tune the room. There are several set of curtains in the back of the auditorium itself that we expose for rehearsals, and retract for performances. We have found that these exposed curtains mimic the acoustic effect of an audience, so we are able to minimize the acoustic differences in the hall between a rehearsal with no audience and a performance. There are other absorptive panels on the side walls of the hall that can be exposed or retracted to influence the hall’s acoustics, but we only expose these panels when using amplified sound.

The other unique feature of the hall is the 170 ton orchestra shell. In addition to being the home to the concert pipe organ, it creates an excellent reflective enclosure for an orchestra and chorus. The acoustician designed the orchestra shell to be too stiff and massive to absorb any of the sound energy that hits it, but reflect all that energy back to the performers and auditorium. Very little sound escapes the enclosure to the backstage areas. The shell gives Overture Hall all the acoustic characteristics of a dedicated concert hall, but allows us to be programmatically flexible. 

The seats are removed from the orchestra pit and the pit is brought up to stage level to create a stage extension that extends 25’ into the hall. A third of the multilevel orchestra risers are out on the stage extension, merging the space of the stage and hall into one.