Calculation and measurement of acoustic factors for the Kirishima International Concert Hall

Abstract

The Kirishima International Concert Hall was designed by architect F. Maki with Ando’s acoustic design theory. It opened on July 22, 1994. The 770 seat main hall which has a volume of 8475 m3 was primarily designed for chamber music. Computer simulations made it clear that the acoustical design of the main hall would be an optimum solution with a plan like a leaf shape and a cross section like a bottom of a ship. These were solutions which satisfied requirements for both acoustical and architectural design concepts of the main hall. Getting a low IACC sound field at the front seat was most important. In order to get a low IACC, sound reflections from the stage to the audience floor were examined and studied in the early design processes. Calculation and measurement of acoustic factors of the sound fields in the main hall show: (1) the calculated and the measured IACCs are good in agreement, (2) IACCs tended lower values of about 0.1 than the calculated ones throughout the seats, and (3) the number of reflections needed for predicting IACC is recommended to be about 40 for the practical method of IACC calculation at the design stage of a hall.