In English

Design of a Bending Wave Loudspeaker

Andreas Rouette
Göteborg : Chalmers tekniska högskola, 2004. Rapport E - Chalmers tekniska högskola, Avdelningen för teknisk akustik., ISSN 0283-8338; E04-01, 2004.
[Examensarbete på avancerad nivå]

The use of bending waves as a source of acoustic radiation has become a very big subject for research in the last years. It has been shown that a loudspeaker based on the principles of bending waves can be applied as a broadband acoustic radiator. The aim of this work is to combine a loudspeaker with a screen on which 3D graphics can be projected. A "loudspeaker screen" based on the principles of bending waves is the result of this thesis. The first part of this work,chapter two, deals with the theoretical background of sound radiation from a plate in bending. Therefore the one and two-dimensional bending wave equation has been analysed. In chapter three some decisions have been made concerning the material for building a physical model. A theoretical model has been designed to calculate the efficiency of the loudspeaker. It has been showed that the loudspeaker has a rather flat radiation around 90 dB for an input force of 1 N. Theoretically the designed loudspeaker works as a good solution for the required application. Some measurements have been done to verify the results of the calculations. Therefore the surface of the plate in vibration has been scanned with the Laser Doppler Vibrometer. The sound pressure level of the plate was measured in the anechoic chamber. In the last chapter one will find some conclusions as a result of the measurements. In addition to that some suggestions for further work have been made.

Nyckelord: bending wave, critical frequency, damping of plates, sound pressure level, driving point mobility, laser Doppler Vibrometer



Publikationen registrerades 2006-08-28. Den ändrades senast 2013-04-04

CPL ID: 303

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