Speaker
Description
Spatial room acoustic measurements have become common practice in room and concert hall acoustics. The authors have been using different spatial microphone-probes in room acoustic measurements for several years. These microphone-probes typically consist of 4 to 8 microphone capsules either omni-directional or cardioid directivity pattern. Slight differences have been noticed in auralisation use as well as when plotting spatiotemporal visualisations based on the measured room impulse responses. This paper presents a study where the performance of three different microphone probes is compared by measuring room impulse responses in controlled test environment. The analysis of the spatial response is done using spatial decomposition method (SDM)[1]. The aim of the study is to find and build an optimal microphone probe for room acoustic measurements for acoustic consulting use. Based on the analysis of spatiotemporal visualisations, an array with 7 microphone capsules (six capsules used for directional analysis) was found to give more accurate reflection tracking compared to 4 capsule arrays. 4 capsule arrays, however, could be sufficiently accurate for visualizing the overall reflection pattern or a certain space to assess the amount of lateral energy against frontal energy and showing the “shape” of the early reflections for instance. The strong reflections from relatively small surfaces, however, could be difficult to pinpoint accurately with 4 capsule arrays. 6-7 capsule array could be accurate enough to pinpoint individual specular reflections for consulting use. Further work is required to confirm these conclusions in real spaces.