Theoretic considerations on how the directivity of a sound source influences the measured impulse response

Abstract

In previous investigations, it has been shown that the directivity of a measurement sound source has a significant influence on the measured room impulse response (RIR). Using a specialized method of analysis, the sources influence can be identified even in the very late part of the RIR even in very reverberant environments. These results seem to be surprising at first and contradict intuitive expectations. In this contribution, the findings are briefly discussed, and the congruence with general room acoustic theory is revised and discussed.

Room transfer function measurement from a directional loudspeaker

“…The directivity of most single driver loudspeaker largely differ from the omnidirectional pattern, hence the ISO 3382 standard [2] for RTF measurement specifies the measurement source to be composed of multiple oscillatory membranes mounted on the surface of a dodecahedron cabinet. As shown in [3,4], even these multi-driver speaker arrangements produce omnidirectional responses only in the low frequencies, and with increasing frequency, they tend to become directional. In order to improve the accuracy of the RTF measurement, Klein et.…”