Experimental Investigation of the Use of Equivalent Sources Model in Room Acoustics Simulations

As an alternative to models based on geometrical acoustics and the computationally intensive Finite Element or Boundary Element models, the Equivalent Sources Model (ESM) has recently been modified and extended from its original application in acoustical holography to simulations of the room acoustics. Previously, numerical simulation results have demonstrated the advantages of room acoustics ESM's (especially when multipoles are used as its equivalent sources) as a flexible reduced order modeling procedure in room acoustics. In the present work, an experimental investigation of the multipole room acoustics ESM was conducted where the sound field generated by a loudspeaker in a small room was measured with different configurations of room surface impedance distributions. The ESM prediction of total sound field in the room was calculated by coupling a free-space ESM (for the source information) with a room acoustics ESM (for the room effect). The ESM predictions were compared with BEM predictions and with the measurements to demonstrate the validity of the room acoustics ESM in a realistic application. Based on these comparisons, w the ESM performance as a function of frequency, room configuration and other experimental conditions is discussed.