Feb 28 2007
With school upgrades and new construction in a constant state of budgetary constraints and cost over runs, any additional classrooms, or space come at a premium price. Technology exists now, that can transform a single room into a multi use room capable of accommodating a number of musical venues.
"As acoustical consultants, we are pretty picky about a sense of envelopment, warmth, and other qualities that can be heard in a great acoustical facility. We are also realists, and multi use spaces often are compromised by the selection of one set of acoustic parameters due to budget. Variable physical acoustics are very expensive to do properly, and when done cheaply, do not work very well; curtains just do not quite cut it," said Seth E. Waltz, President of AVL Designs, Incorporated. "We believe the (AFC) system will finally allow budget conscious projects truly variable acoustics."
The basic concept behind the Yamaha AFC system is it utilizes acoustical feedback to add energy to the sound field. For example, when someone plays a musical instrument in a room, the listener hears the direct sound wave, and the physical reflection of that sound wave. AFC microphones placed in the room also receive this sound. After "gain" control, the sound is reproduced from the room AFC speakers, and played back. This sound then strikes the microphones once again, which feed energy to the room. When the energy in the room is increased, the reverberation time must be extended in the time domain.
Depending on the size of the venue, the AFC system uses 4-8 microphones, 8-100 speakers, FIR filters, equalizers, and amplifiers. The system is best suited of rooms of more than 800 square feet; however, it may be used in smaller spaces depending on the purpose and size of the room.
The AFC system was recently installed in the auditorium at Vestal High School in Vestal, New York. This venue has four presets for each performance. "Choral" sound is bright with clear high frequencies. The bass sound of "Orchestral" is longer than those of other patterns, and this pattern has high spaciousness. "Chamber Music" pattern has the same characteristics as "Orchestral", but the room size is reduced. "Jazz Ensemble" pattern enhances loudness and realizes high clarity.
"At Vestal High School, the room had little designed in physical diffusion due to a limited budget. The AFC system provided a well diffuse sound field, very convincing with varied sources. I think most people who come into the room for a performance will think the room really sounds that good. They will never have any sense of an electronic system being in place; unless the system is suddenly turned off," said Mr. Waltz.
The Yamaha AFC is designed with venue presets, so it is truly a set, and forget system.