Efficient Designs for Broadband Linear Arrays

Linear electroacoustic arrays are useful for various applications in audio acquisition and reproduction. For robust broadband performance, a filter network is typically incorporated to achieve roughly frequency-invariant beamforming. In this paper, we are concerned with the design of cost-effective broadband arrays of limited size for consumer audio applications. Filter-based broadband beamformers are suboptimal for such applications due to high cost and the large number of elements generally needed to achieve invariance. Here, three alternative design methods are presented which lead to effective far-field broadband performance of small arrays at low cost: allpass weighting, optimal nonuniform spacing, and optimal delay dispersion. Performance improvements are demonstrated for each method and various design tradeoffs are considered