Loudspeakers and Microphones
Compact spherical loudspeaker arrays permit controllable directivity, and electroacoustic music recently became interested in using their beamforming capacities to compose spatial music. In this application, directivities of 3rd-order or higher turned out to offer a sufficiently precise horizontal control.
A recent paper proposed the 393 array that permits 4th-order horizontal and 2nd-order vertical control, housing 15 independently controlled transducers. Our engineering brief proposes the 170 compact spherical loudspeaker design that is DIY-3D-printable and only uses 8 audio channels. The 170 array houses seven 2.5” broadband transducers that allow third-order horizontal beamforming and a 6” subwoofer.
We make the CAD model, electroacoustic measurements, and control filters openly accessible and show its beampatterns for verification, based on those measurements.
Authors: Valerian Drack (University of Technology, Graz), Franz Zotter (Institute of Electronic Music and Acoustics, University of Music and Performing Arts, Graz, Austria), and Natasha Barrett (Norwegian Academy for Music)