Abstract by Kennen Brooks
Physics and Astronomy
DESIGN OF A NEW ACOUSTICAL DIRECTIVITY MEASUREMENT SYSTEM
This presentation explores the design and construction of a modular spherical directivity
measurement system used to characterize acoustic sources. It allows for different array sizes,
near-field and far-field measurements, easy assembly, movement, and disassembly. The
system comprises of a pair of Unistrut rails supported near the ceiling wedges of the large BYU
anechoic chamber, a trolley with a braking system, a moveable computer-controlled turntable,
a collection of minimally obtrusive and adjustable microphone arc arrays, and a structure below
the chamber cable floor to support and align sources above the floor. The turntable rotates the
array about a source for high-resolution spherical or hemispherical sampling. Each system
element has been designed for structural integrity, safety, and minimal acoustic scattering.
When possible, cross sections have been reduced to less than a quarter wavelength of the
highest practical measurement frequency or absorptively treated.