45. Directivity-Customizable Loudspeaker Arrays Using Constant-Beamwidth Transducer (CBT) Overlapped Shading

AES Convention: 139 Paper Number:9478
Publication Date: 2015-10-06

In this work a multiple constant-beamwidth transducer (Multi-CBT) loudspeaker array is proposed that is constructed by applying multiple overlapping CBT Legendre shadings to a circular-arc or straight-line delay-curved multi-acoustic-source array. Because it has been proved theoretically and experimentally that the CBT array provides constant broadband directivity behavior with nearly no side lobes, the Multi-CBT array can provide a directivity-customizable sound field with frequency-independent element weights by sampling and reconstructing the targeted directivity pattern. Various circularly curved Multi-CBT arrays and straight-line, delay-curved Multi-CBT arrays are analyzed in several application examples that are based on providing constant Sound Pressure Level (SPL) on a seating plane, and their performance capabilities are verified. The power of the method lies in the fact only a few easily-adjustable real-valued element weights completely control the shape of the polar pattern that makes matching the polar shape to a specific seating plane very easy. The results indicate that the desired directivity patterns can indeed be achieved.

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Feng, Xuelei; Shen, Yong; Keele, Jr., D.B. (Don); Xia, Jie; 2015; Directivity-Customizable Loudspeaker Arrays Using Constant-Beamwidth Transducer (CBT) Overlapped Shading [PDF]; Nanjing University, Nanjing, Jiangsu, China; DBK Associates and Labs, Bloomington, IN, USA; Paper 9478; Available from: https://aes2.org/publications/elibrary-page/?id=18034