Study On Variable Acoustics In Multipurpose Halls

With the rapid development of Chinese economy,large numbers of multipurpose halls are springing up in coastal as well as inland areas.Multipurpose halls have variety of functions that lead to high utilization and good economy returns,which marks a promising direction for development in the future.However,when concerning acoustics,most of these halls are not comparable to the similar ones at abroad which have advanced technology in variable acoustics.Much attention has been paid to the functionality rather than the appropriate acoustical environment for these halls.In this paper,the design and implementation methods of variable acoustics in multipurpose hall have been explored.A parameterized evaluation method has been proposed based on a specific summary of parameters in room acoustics.The principle,approach and applicability of different kinds of passive/active variable acoustics have been summarized,combining with case studies of 10 typical multipurpose halls and the comparison of characteristics and effects with each other.This study also focuses on the effects of orchestra shells on variable acoustics.Acoustical experiments to orchestra shells in two multipurpose halls in Tsinghua University were conducted,including in-situ measurements and computer simulations.By quantitative study of structural modifying,it is found that different morphological structures and status of orchestra shells change the acoustical environment in different ways.This study aims to study different approaches of variable acoustics in multipurpose halls and tailor one that adapts to Chinese situation.It also intends to explore the acoustical effects of orchestra shells for variable acoustics,which contributes to the fields including architectural design,acoustics,stage machinery,art management,etc.