Spatial analysis of room impulse responsescaptured with a 32-capsules microphonearray

ABSTRACT The authors developed a new measurement system, which captures 32-channels impulse responses by means of a spherical microphone array and a matrix of FIR filters, capable of proving frequency-independent directivity patterns. This allows for spatial analysis with resolution much higher than what was possible with obsolete sumand- delay beamforming. The software developed for this application creates a false-colour video of the spatial distribution of energy, changing with running time along the impulse response duration. A virtual microphone probe allows to extract the sound coming from any specific direction. The method was successfully employed in three concert halls, providing guidance for correcting some acoustical problems (echo, focusing) and for placing sound reinforcement loudspeakers in optimal positions.