Acoustical Renovation of Large Auditorium to Enhance Sound Strength and IACC

The Grand Theater in the Sejong Performing Arts Center is a proscenium theater with 3,022 seats. Originally built in 1978, the first renovation was conducted in 2004 to provide variable reverberation time (RT) using a sound system. Recently, a renovation was again planned to enhance the acoustic quality, especially sound strength (G) and spatial responsiveness (IACC), based on architectural acoustic design. The orchestra shell and various ceiling/wall reflectors were redesigned to improve the acoustic quality in calculation of G and IACC. The side balconies were added to provide lateral reflections to the audience sitting in the stalls. Materials of the walls and chairs were changed for longer RT and higher G. In this paper, the results of a computer simulation as well as the acoustical design process were presented.