| Summary: | 碩士 === 國立交通大學 === 工學院聲音與音樂創意科技碩士學位學程 === 98 === Faced with various conflicting issues arising from sensitivity, distortion, bandwidth and miniaturization requirements for earphones, it is desirable to develop a systematic way to attain the design that would meet these requirements. Based on a lumped parameter model, the design of the earphone enclosure is optimized using the simulated annealing (SA) algorithm. Experimental results obtained using a type 3.3 artificial ear (IEC 711 ear simulator) reveals that the optimized design has resulted in significant enhancement of performance, complying with the frequency response mask dictated in the 3GPP2 standard.
Omni-directional sources are required in some special acoustical measurements as well as audio reproduction applications. This thesis aims to design a dodecahedral loudspeaker source to approximate an omni-directional source. Twelve drivers are mounted in an enclosure made of stainless steel. In order to predict the directional response, the equivalent source method (ESM) is employed to calculate the pressure radiation pattern of the source. In addition to the numerical simulation, practical measurement of the directional response was performed using the turn table. Both numerical and experimental results show demonstrated the satisfactory omni-directional property of the source.
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