Photo credit: Tim Safranek
The Cleveland Institute of Music (CIM) in Cleveland, Ohio recently commissioned a recital hall and state-of-the-art control room, which was designed by Dr. Peter D'Antonio, adjunct professor of acoustics at the Institute. Bruce Egre, head of the conservatory's audio recording degree program, installed an ATC (Acoustic Transducer Company) 5.1 surround system comprising SCM150 ASL speakers.
The two new rooms were added on to one of the Institute's existing buildings, with the recital hall in the front and the control room in the back. "The new control room was designed and built from the ground up to be acoustically precise," says Egre. Tielines from the Institute's concert hall, a small overdub room and the recital hall feed into the control room.
With the planned links to performance spaces in the complex, D'Antonio and Egre decided to design a world-class facility for the school. According to D'Antonio, "The first challenge was to orient the room in the available space in order to provide a symmetrical listening environment. Following this, we utilized our Room Sizer program to determine the optimal dimensional ratios for uniform modal response.
"Every approach that is currently known has been applied to this control room with the goal of an extended and flat low-frequency response," D'Antonio says. RPG acoustical products were chosen to minimize reflections, add absorption in specific areas and diffuse wavefronts in others. "We also had to take into account the fact that it is an educational space and needs to accommodate more people than a typical control room. We had to be very sensitive to the amount of real estate we used for low-frequency control."
New Modex Plate resonators, said to provide absorption from 50 to 500 Hz, are installed in all of the available dihedral wall intersections, where pressure is high. Broadband absorption is provided with a variant of the Modex Plates. The LF Modex Plates are installed in the rear of the room and on the upper front wall areas, and the broadband version is installed directly behind the L/R/C loudspeakers.
Four in-phase ATC SCM.1/15 ASL subwoofers, located a quarter of the distance from adjacent walls, provide additional low-frequency control. This placement prevents modes below the crossover from being energized. In addition, a pit measuring roughly 6.5x10x4 inches was created at the first bounce position between the L/R/C speakers and the listening position. The pit is filled with Modex Broadbands to control the interference caused by this floor reflection when it combines with the direct sound. The pit is covered with carpeting and the console is mounted on rails spanning the pit.