OVI Featured In Architectural Record For Work At EMPAC
OVI Featured in Architectural Record For Work On EMPAC
“And the award for best sound effects goes to•••
ACOUSTICS GET A STARRING ROLE IN THE DESIGN OF A NEW PERFORMING ARTS CENTER
By Josephine Minutillo
Studio 2, on the other hand, sits on completely separate foundations from the rest of the building. “There was concern about noise literally traveling down into the ground and cross-talking between concrete beams,” saysSchwitter. “Above Studio 2 are additional spaces that span over the studio, but don’t rest on it.” These structural gymnastics were further complicated by New York State’s adoption of the Inte r national Building Code in 2002, which dictated that the building ad dress seismic issues. Because of the sloping hillside into which EMPAC is embedded, it was placed in a higher seismic category than is typical for the region. As each element of the building is a unique structure, in dividual venues had differing drift characteristics. All movements were coordinated with up to 4-inch joints in many areas.
Beyond the studios’ unique structural aspects were their highly specialized interior requirements. Studio I is optimized for scientific visualization, multiscreen and immersive performances, and dance; Studio 2 for music recitals and recordings. Acoustic requirements were stringent for both. Each studio’s walls are lined with a series of specially developed gypsum acoustic panels, arranged as a grid, which reflect and scatter sound. The panels in Studio 1 feature a perforated metal surface backed with absorptive material. Inspired by the bark of a tree, the panels are com puter-milled to contain random, pocked surfaces. “Sound waves interfere with each other when they experience repetitive surfaces,” says Kirkegaard.
Each time a traveling sound wave bounces back from a room surface, its strength is weakened by the sound absorption of that sur face. The time it takes for a loud sound to decay to inaudibility after being cut off is called the reverberation time (RT). According to Kirkegaard, the RT in Studio I prior to installing the acoustic panels (and the resonant absorbers behind them) was between 7 and 10 seconds-quite long. After installation of these critical elements, the RT was reduced to less than a second. (By contrast, the RT in the concert hall is closer to 2 seconds.)
Both studios feature a wire grid ceiling that provides a walk able surface upon which technicians can work to adjust the room to fit the needs of individual performances. Banners, diffusers, and screens can be hung from this surface for use in video projections, three dimensional presentations, and immersive environments.
“The studios were probably the most complicated spaces to design,” Gallagher concedes. “The noise criteria was as strict for them as for the concert hall. Nowhere else in the world do you have a building with not one or two, but four world-class acoustic spaces.” The criteria Gallagher refers to are Room Criteria (RC), which measures the background noise in a space over a certain frequency range. While the average RC range for ordinary spaces like restaurants and even libraries is between 30 and 40, the requirements for all the spaces at EMPAC were RCI5- in other words, quiet enough to hear a pin drop.
See more about the facility in this video:
See more about the project here: https://www.oviinc.com/project/empac/
See the full PDF: Architectural Record Feb 2009