A Spherical Microphone Array For Synthesizing Virtual Directive Microphones In Live Broadcasting And In Post Production

The paper describes the theory and the first operational results of a new multichannel recording system based on a 32- capsules spherical microphone array. Up to 7 virtual microphones can be synthesized in real-time, choosing dynamically the directivity pattern (from standard cardioid to 6th-order ultradirective) and the aiming. A graphical user’s interface allows for moving the virtual microphones over a 360-degrees video image. The system employs a novel mathematical theory for computing the matrix of massive FIR filters, which are convolved in real time and with small latency thanks to a partitioned convolution processor.