A New Directional Model of Sound Source for String Quartet Used in Geometrical Acoustic Simulation

Abstract

The purpose of this research is to make clear the ef 葩ct of fUndamental characteristics of sound source on the acoustical properties of concert auditoria and present an acoustlcal design method considering the directional characteristics of sound sources ． In this paper ， sning quartet is dealt as a case study ． Acoustical quantities are calculated in v ， ariab］ e auditorium models by means of geometrical simulation when the directiona 亘characterist 正 cs of string quartet are modeled on the measured directivity of violin ， viola and cello ． The re 【 ation between the directionality and the evaluation of sound field is examined ． The result shows that it is di伍 cult to grasp the sound fie 藍 d fbr each source only by using an omni イ 11rectional source ， and a directiona 蓋sound source model fbr string quartet used in geometrical acoustic simulation is proposed ． The differences between the acoustical quantities ca 正 culated with the proposed source and with an omni −directional source are examined in real auditorium models ． From the result ， it is co 面 ed that the new directional modei of sound source is valid in the prediction of sound field fbr string quartet ． Careful consideration on directional characteristics of musical instruments hke strings is necessary fbr good acoustics in concert halls ， Keyivords ' Directional characteristiCS ofsound souree ． ・Acoustical parameters ， Geometrical acoustic simulation ， Acoustic design 音源