title: Loudspeaker line array educational demonstration.
abstract: This paper presents a physical demonstration of an audio-range line array used to teach interference of multiple sources in a classroom or laboratory exercise setting. Software has been developed that permits real-time control and steering of the array. The graphical interface permits a user to vary the frequency, the angular response by phase shading, and reduce sidelobes through amplitude shading. An inexpensive, eight-element loudspeaker array has been constructed to test the control program. Directivity measurements of this array in an anechoic chamber and in a large classroom are presented. These measurements have good agreement with theoretical directivity predictions, thereby allowing its use as a quantitative learning tool for advanced students as well as a qualitative demonstration of arrays in other settings. Portions of this paper are directed toward educators who may wish to implement a similar demonstration for their advanced undergraduate or graduate level course in acoustics.
authors.affiliation: Acoustics Research Group, Department of Physics and Astronomy, Brigham Young University, N283 ESC, Provo, Utah 84602, USA. bea@byu.edu
authors.forename: Brian E
authors.initials: BE
authors.lastname: Anderson
authors.forename: Brad
authors.initials: B
authors.lastname: Moser
authors.forename: Kent L
authors.initials: KL
authors.lastname: Gee