0
Research Papers

Modal Analysis of a Loudspeaker and Its Associated Acoustic Pressure Field

[+] Author and Article Information
Derek Kuo

 Merry Electronics Co., Ltd., No. 22, 23rd Road, Taichung Industrial Park, Taichung, Taiwan 40724, R.O.C.derek.kuo@merry.com.tw

Y. C. Shiah

Department of Aerospace and Systems Engineering, Feng Chia University, Taichung, Taiwan 40724, R.O.C.ycshiah@fcu.edu.tw

Jin H. Huang

Electroacoustic Graduate Program, and Department of Mechanical and Computer-Aided Engineering, Feng Chia University, Taichung, Taiwan 40724, R.O.C.jhhuang@fcu.edu.tw

J. Vib. Acoust 133(3), 031015 (Mar 31, 2011) (11 pages) doi:10.1115/1.4003268 History: Received June 17, 2009; Revised September 01, 2010; Published March 31, 2011; Online March 31, 2011

This paper presents a modal analysis and the sound pressure field for the vibrator membrane of an actual portable loudspeaker. Unlike the conventional way to model the membrane’s edge under a simply supported condition, the present approach takes the glued edge to be elastically supported. With theoretical derivations for such treatment, this paper also presents the associated near-field and far-field sound pressures that have not been reported in the open literature. Fundamentally, calculation of the near-field sound pressure solution for the elastically supported membrane has difficulty with numerical convergence. In this paper, integral regularization is employed to enforce the convergence. From the viewpoint of acoustic engineers, the analysis may effectively help to tailor the design of a loudspeaker that caters to consumers’ preference.

Copyright © 2011 by American Society of Mechanical Engineers
Your Session has timed out. Please sign back in to continue.

References

Figures

Grahic Jump Location
Figure 11

Near-field response for the simply supported condition (k0a=70) at R=0 and ka=0.15 (595 Hz): (a) the sound pressure and (b) the mode shape (amplitude)

Grahic Jump Location
Figure 12

Near-field response for the free vibration condition (k0a=0) at R=0 and ka=19.9 (77,507 Hz): (a) the sound pressure and (b) the mode shape (amplitude)

Grahic Jump Location
Figure 13

Near-field response for the simply supported condition (k0a=70) when R=0 and ka=18.7 (72,815 Hz): (a) the sound pressure and (b) the mode shape (amplitude)

Grahic Jump Location
Figure 16

Near-field sound pressure and mode shapes of the elastically supported membrane (R=0, k0a=1.64): (a) mode 2, (b) mode 6, and (c) mode 10

Grahic Jump Location
Figure 4

Far-field pressure for two extreme conditions at R=0.1 m and ka=0.04 (155 Hz), frequency lower than the fundamental one: (a) k0a=0 (free vibration without glue) and (b) k0a=70 (simply supported vibration for hard glue materials)

Grahic Jump Location
Figure 3

Mode shapes (up to the seventh mode) of circular plates for two extreme conditions: (a) k0a=0 (free vibration without glue) and (b) k0a=70 (simply supported vibration for hard glue materials)

Grahic Jump Location
Figure 2

Simplified model for the membrane glued to the yoke

Grahic Jump Location
Figure 1

Components of the Merry DSH945 loudspeaker

Grahic Jump Location
Figure 5

Far-field pressure for two extreme conditions at R=0.1 m and ka=2 (7799 Hz), frequency higher than the fundamental one: (a) k0a=0 (free vibration without glue) and (b) k0a=70 (simply supported vibration for hard glue materials)

Grahic Jump Location
Figure 6

The first three vibration modes whose effective areas correspond to the sound pressure level for two extreme conditions: (a) k0a=0 (free vibration without glue) and (b) k0a=70 (simply supported vibration for hard glue materials)

Grahic Jump Location
Figure 7

Radiation power at R=0.1 m showing the resonance frequencies for extreme conditions: (a) k0a=0 (free vibration without glue) and (b) k0a=70 (simply supported vibration for hard glue materials)

Grahic Jump Location
Figure 8

Near-field sound pressure for the free vibration condition (k0a=0) at R=0 at ka=0.01 (39 Hz): (a) the imaginary part and (b) the real part

Grahic Jump Location
Figure 9

Near-field sound pressure for the simply supported condition (k0a=70) at R=0 and ka=0.01 (39 Hz): (a) the imaginary part and (b) the real part

Grahic Jump Location
Figure 10

Near-field response for the free vibration condition (k0a=0) at R=0 and ka=0.15 (1090 Hz): (a) the sound pressure and (b) the mode shape (amplitude)

Grahic Jump Location
Figure 14

Far-field sound pressure for the elastically supported condition (k0a=1.64) when R=0.1 m at (a) a typical low frequency of 39 Hz (ka=0.01) and (b) a typical high frequency of 7799 Hz (ka=2)

Grahic Jump Location
Figure 15

Radiation power of the elastically supported membrane of DSH956 (k0a=1.64) when R=0.1 m, indicating the resonance frequencies

Tables

Errata

Discussions

Some tools below are only available to our subscribers or users with an online account.

Related Content

Customize your page view by dragging and repositioning the boxes below.

Related Journal Articles
Related eBook Content
Topic Collections

Sorry! You do not have access to this content. For assistance or to subscribe, please contact us:

  • TELEPHONE: 1-800-843-2763 (Toll-free in the USA)
  • EMAIL: asmedigitalcollection@asme.org
Sign In