Acoustical Testing Confirms Plans

Date: July 24, 2007

Author: Kauffman Center

It would be an understatement to say that Kauffman Center planners expect “great” acoustics from the concert hall.  “Think of the concert hall as the instrument through which musicians will perform.  Since we want to build a Stradivarius for musicians, acoustics are of supreme importance,” says Jane Chu, president and CEO of the Kauffman Center.

The rounded and angular shapes of this concert hall require a level of acoustical attention not demanded by the theaters we are most familiar with in Kansas City.  Proscenium theaters—those in which the audience sits in a box-shaped room facing a stage—have very predictable acoustics.

The Kauffman Center concert hall, on the other hand, has vineyard-style seating arranged in an oval shape around the space where musicians perform. To test the acoustics of this unique space, a one-tenth scale model was built, precisely replicating the interior of the hall.  Built by Omni Models of Kansas City last fall, the model is 13 feet high, 18 feet long and 12 feet wide.  It has been used twice for sophisticated acoustical testing conducted by Nagata Acoustics.

Initial testing took place in January 2007.  “Our team worked from January 8th to the 30th in Kansas City and we did identify some detrimental echoes in the concert hall model,” says Yasu Toyota, head of the Nagata Acoustics team.  “After determining which areas were causing the echoes we worked with the architects to find solutions.”  Then Omni Models went back to work, making adjustments prior to re- testing in July 2007.

Recommended changes included the angles of some walls and adding some more absorptive materials in areas where the echoes occurred.  While the model is relatively small, the changes demanded intensive work.  “Our builders spent four months making adjustments to the model,” said Greg Sizemore of Omni Models.  “Kansas City’s rain and sticky June weather really made it difficult to get varnishes dry before testing could begin again.” 

Acoustical testing is done using sophisticated equipment, some designed by Nagata Acoustics themselves.  “We use custom-made speakers and special microphones that can emit and capture the very high frequencies that we must use in a one-tenth scale model,” says Kayo Kimotsuki-Kallas who was part of the Nagata team. 

Nagata conducts all tests with a full “audience” in place.  The 1,600 “people” are dressed in fabric that was pre-tested to assure that it represents the absorption factor of an audience.  “When the acoustics are good in a hall with a full audience, you can also predict good sound in a partially empty hall,” Kayo shares.

Second time was charm in this case.  Recent testing found no unwanted echoes or additional problems, according to the Nagata team. So the interior design plans are confirmed and ready to be used as building progresses.

Want to see the one-tenth scale model?  It’s available for group tours and individual visits by appointment. Call 816-994-7200 to arrange a tour.

For more information about acoustical testing, read our interview with Yasu Toyota.