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Influences of Diaphragm Materials on the Performance of a Microspeaker

Published online by Cambridge University Press:  10 April 2015

C.-N. Wang ,
J.-R. Chang  and
W.-C. Chang
C.-N. Wang
Affiliation:
Department of Engineering Science and Ocean Engineering, National Taiwan University, Taipei, Taiwan
J.-R. Chang*
Affiliation:
Department of Engineering Science and Ocean Engineering, National Taiwan University, Taipei, Taiwan
W.-C. Chang
Affiliation:
Department of Engineering Science and Ocean Engineering, National Taiwan University, Taipei, Taiwan
*
* Corresponding author (meibus@yahoo.com.tw)
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Abstract

The purpose of this study was to investigate the influence of a diaphragm material on the performance of a microspeaker. The finite element method was adopted to analyze the mode shapes and the displacement of the diaphragm under a force load. The Rayleigh integral was then calculated to determine the radiated sound pressure and frequency response of a loudspeaker. The location of the voice coil was also investigated. Locating the voice coil at approximately 53% to 76% of coil-radius/diaphragm-radius ratio yielded a favorable mode shape distribution and performance for the loudspeaker. In addition, two loudspeaker designs, Models A and B, were analyzed to determine the effects of the diaphragm material. The numerical results of Models A and B, indicated that the mode shape is a crucial factor when considering the materials used in a loudspeaker diaphragm. The property of a material at the inflection point of a mode shape obviously affects the modal frequency. According to this observation, the most crucial first and second axial symmetric modes in a loudspeaker design can be adjusted and the performance can be improved.

Keywords

LoudspeakerDiaphragmMode shape
Type
Research Article
Information
Journal of Mechanics , Volume 31 , Issue 3 , June 2015 , pp. 331 - 336
Copyright
Copyright © The Society of Theoretical and Applied Mechanics, R.O.C. 2015 

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References

REFERENCES

1.Siemens, E. W., US Patent No. 149797 (1874).Google Scholar
2.Siemens, E. W., German Patent No. 2355 (1877).Google Scholar
3.Rice, C. W. and Kellogg, E. W., “Notes on the Development of a New Type of Hornless Loud Speaker,” Journal of the Audio Engineering Society, 30, pp. 512–521 (1982).Google Scholar
4.Villchur, E. M., “Problems of Bass Reproduction in Loudspeaker,” Journal of the Audio Engineering Society, 5, pp. 122–126 (1957).Google Scholar
5.Villchur, E. M., “A Method of Testing Loudspeakers with Random Noise Input,” Journal of the Audio Engineering Society, 10, pp. 306–309 (1962).Google Scholar
6.Thiele, A. N., “Loudspeakers in Vented-Boxes: Part I,” Journal of the Audio Engineering Society, 19, pp.382–392 (1971).Google Scholar
7.Thiele, A. N., “Loudspeakers in Vented-Boxes: Part II,” Journal of the Audio Engineering Society, 19, pp.471–483 (1971).Google Scholar
8.Small, R., “Direct-Radiator Loudspeaker System Analysis,” Journal of the Audio Engineering Society, 20, pp. 383–395 (1972).Google Scholar
9.Small, R., “Closed-Box Loudspeaker Systems, Part I: Analysis,” Journal of the Audio Engineering Society, 20, pp. 798–808 (1972).Google Scholar
10.Small, R., “Closed-Box Loudspeaker Systems, Part II: Synthesis,” Journal of the Audio Engineering Society, 21, pp. 11–18 (1973).Google Scholar
11.Small, R., “Vented-Box Loudspeaker Systems, Part I: Small-Signal Analysis, Part II: Large-Signal Analysis, Part III: Synthesis, Part IV: Appendics,” Journal of the Audio Engineering Society, 21, pp. 363–372, 21, pp. 438–444, 21, pp. 549–554, 21, pp. 635–639 (1973).Google Scholar
12.Bai, M. R. and Liao, J., “Acoustic Analysis and Design of Miniature Loudspeakers for Mobile Phones,” Journal of the Audio Engineering Society, 53, pp. 1061–1076 (2005).Google Scholar
13.Bai, M. R. and Chen, R. L., “Optimal Design of Loudspeaker Systems Based on Sequential Quadratic Programming (SQP),” Journal of the Audio Engineering Society, 55, pp. 44–54 (2007).Google Scholar
14.Bai, M. R., Liu, C. Y. and Chen, R. L., “Optimization of Microspeaker Diaphragm Pattern using Combined Finite element-Lumped Parameter Models,” IEEE Transactions of Magnetics, 44, pp.2049–2057 (2008).Google Scholar
15.Kwon, J. H., Hwang, S. M. and Kim, K. S., “Development of Slim Rectangular Microspeaker used for minimultimedia Phones,” IEEE Transactions on Magnetics, 43, pp. 2704–2706 (2007).Google Scholar
16.Bai, M. R., Chen, R.-L. and Wang, C.-J., “Electroa-coustic Analysis of an Electret Loudspeaker Using Combined Finite-Element and Lumped-Parameter Models,” Journal of the Acoustic Society of America, 125, pp. 3632–3640 (2009).Google Scholar
17.Shiah, Y. C., Huang, J. H. and Xue, Y.-L., “The First Damped Frequency with Maximum Sound Pressure of a Miniature Loudspeaker for Cellular Phones,” Journal of Mechanics, 26, pp. 473–482 (2010).Google Scholar
18.Kuo, Derek, Shiah, Y. C. and Huang, Jin. H., “Modal Analysis of a Loudspeaker and its Associated Acoustic Pressure Field,” Journal of Vibration and Acoustics, 133, p. 031015 (2011).Google Scholar
19.Shiah, Y. C., Her, H.-C., Huang, J. H. and Huang, B., “Parametric Analysis for a Miniature Loudspeaker Used In Cellular Phones,” Journal of Applied Physics, 104, p. 104905 (2008).Google Scholar
20.Huang, J. H., Her, H.-C., Shiah, Y. C. and Shin, S.-J., “Electroacoustic Simulation and Experiment on a Miniature Loudspeaker for Cellular Phones,” Journal of Applied Physics, 103, p. 033502 (2008).CrossRefGoogle Scholar
21.Kim, W., Jang, G. W. and Kim, Y. Y., “Microspeaker Diaphragm Optimization for Widening the Operating Frequency Band and Increasing Sound Pressure Level,” IEEE Transactions on Magnetics, 46, pp. 59–66 (2010).CrossRefGoogle Scholar
22.Lee, C. M., Kwon, J. H., Kim, K. S., Park, J. H. And Hwang, S. M., “Design and Analysis of Microspeakers to Improve Sound Characteristics in a Low Frequency Range,” IEEE Transactions on Magnetics, 46, pp. 2048–2051 (2010).Google Scholar
23.Chao, P. C. P. and Wang, I. T., “Dynamical Modeling and Experimental Validation of a Micro-Speaker with Corrugated Diaphragm for Mobile Phones,” Microsystem Technologies, pp. 1241–1252 (2007).Google Scholar
24.Shahosseini, I., Lefeuvre, E., Moulin, J., Woytasik, M., Martincic, E., Pillonnet, G. and Lemarquand, G., “Electromagnetic MEMS Microspeaker for Portable Electronic Devices,” Microsystem Technologies, pp.879–886 (2013).Google Scholar
25.Shahosseini, I., Lefeuvre, E., Moulin, J., Martincic, E., Woytasik, M. and Lemarquand, G., “Optimization and Microfabrication of High Performance Silicon-Based MEMS Microspeaker,” IEEE Sensors Journal, 13, pp. 273–284 (2013).CrossRefGoogle Scholar