Sound Radiation of Composite Flat-Plate Excited by Rectangular Transducer
| Autor: | Huang, Yi-Chiao, 黃奕樵 |
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| Rok vydání: | 2009 |
| Druh dokumentu: | 學位論文 ; thesis |
| Popis: | 98 This thesis studies the sound radiation of flat-plate loudspeakers using rectangular transducers. Loudspeakers are usually made of long and narrow shape to fit the limited space in slim electronic products. In general, the long rectangular radiating plates are excited by circular transducers for sound radiation. However, the size of the circular transducer is limited by the narrow width of the radiating plate. The small transducer may produce low sound pressure level (SPL) and cause a major dip in mid frequency range. To circumvent the above shortcomings, a rectangular transducer is used to excite the panel for sound radiation. In this way, it increases the stroke of the radiating plate to raise sound pressure. On the other hand, it changes the deflected shape of the radiating plate to improve the SPL curve. The study contains two parts. In first part, the software ANSYS is used to determine the theoretical SPL curve of the plate; the effects of the deflected shape on radiating plate and the aspect ratio of the rectangular voice coil are studied to eliminate any large sound pressure dip on the SPL curve. In the second part, ANSYS is again used to analyze the magnetic flux of a rectangular transducer, the design of the rectangular transducer is modified to increase the Lorentz force for raising the loudspeakers sensitivity. Base on above results, a design procedure is proposed for choosing appropriate panels and transducers that can produce good SPL curves for rectangular speakers. At last, a number of loudspeakers are fabricated and tested to verify the proposed design procedure. |
| Databáze: | Networked Digital Library of Theses & Dissertations |
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