Principles of Acoustic Design
Good acoustic design requires knowledge of the physics of sound, the engineering qualities of materials, and the unique attributes of music and then applying this knowledge to building construction to create a facility that allows listeners to have an outstanding aural experience.
Three outcomes were sought when designing the Music Center:
- Music should be optimally heard (including an excellent “ring”) throughout the entire performing venues.
- Sounds outside the building needed to be minimized, if not entirely eliminated (i.e. the bad sounds needed to be kept out, including the sounds of the trains that frequently run through the Goshen College campus)
- Sounds created in the space should not disturb adjacent music spaces in the building (i.e. a jazz band rehearsal should not affect the choir rehearsal in the adjacent room)
Careful planning and close monitoring of the construction process accomplished all of the above.
A great concert hall has both sound isolation and reverberation. These two qualities received special attention in designing the Music Center.
When a sound is produced in a concert venue, the reverberation of the hall (often called “ring”) can be timed until that sound has completely disappeared. Longer reverberation is desirable for a music space as opposed to a theatrical space, where clarity and intelligibility of speech is more important than ring.
Longer reverberation is difficult to achieve. To be successful, planners must create adequate cubic volume and limit sound absorbing material. An additional consideration when building is to have adequate mass (weight) in all exposed surfaces; it is important to have hard surfaces with no hollow spaces beneath. The Music Center has concrete block walls in the entire building that are completely filled with concrete grout, producing a solid concrete wall 10 inches thick.
The result. Many of the great halls in the United States have reverberation time of two seconds, such as the Kennedy Center in Washington, D.C. Some concert halls, such as Carnegie Hall in New York City, ring for nearly three seconds. When the tests were completed, the actual reverberation time of the Music Center exceeded three seconds, something that delighted the acousticians and Goshen College musicians!
Adjustability of the “ring’ is possible throughout the facility by deploying sound-absorbing curtains and panels, offering endless possibilities for various types of music (i.e. full reverberation for choral music and some orchestral music; less reverberation for jazz and Contemporary Christian music).
Because of the train mentioned above, and because the Music Center often has multiple activities going on at once, sound isolation was also critically important. Sound is vibration—in the air and also into the materials of a structure. Isolation of sound assures that vibrations do not pass from one space to another. The Music Center has much “double construction” to provide this isolation.
Separation of foundations, walls and steel structures was achieved with double walls, foam padding, corrugated cardboard and air spaces. Sauder Concert Hall has complete isolation from the two side sections of the building—from foundation to roof—that is crossed only by a limited number of electrical and plumbing items.
Similar isolation is provided around the two rehearsal rooms and between the first and second floors of the south side of the Music Center, which houses the practice rooms, teaching studios and classrooms.
Acoustic Characteristics – learn more about clarity, loudness, liveliness, reverberance, echoes, dynamic range, envelopment, spaciousness, warmth, and even silence!
Acoustic Appreciation Exercises – Questions to ask yourself while hearing music.