出音管道對微型揚聲器低頻輸出影響探討

隨著3C產品蓬勃發展，手機、平板、筆記型電腦等的功能越來越講究，其中音質部分也是大家重視的地方。然而，這些產品使用的揚聲器為微型揚聲器，因為微型揚聲器體積小，適合放入現在越來越講究體積大小的智慧型裝置，但微型揚聲器在低頻部分的表現不佳，提升其低頻性能一直是理想的目標。為了改善微型揚聲器低頻不足的缺點，本研究提出一個具有長管道的前腔體，此長管道連接前腔與出音孔，藉由此前腔的第一共振頻率，使得微型揚聲器在此腔體中，低頻區段的輸出值能有所提升。本論文利用有限元素分析軟體，分析前腔體的共振頻率，且模擬微型揚聲器結合前腔體的頻率響應，並採用電聲分析系統CLIO來做實驗驗證之。之後經由模擬分析來探討管道長度、管道截面積大小、前空間大小對揚聲器系統的頻率響應影響，這些結果可以對往後設計管道前腔做為參考的依據。

關鍵字

微型揚聲器；有限元素法；前腔體；共振頻率；頻率響應

並列摘要

With the development of 3C products,the functions of mobile phones,tablets, notebook computers,etc. are becoming more and more important,and the sound quality is also the part that everyone pays attention to.However, the speakers used in these products are micro-speakers.The micro speakers are suitable for smart device because of its size,but the micro speakers are not performing well in low frequency.It is our ideal goal to improve its performance in low frequency. In order to improve the shortcomings of the microspeaker,this study proposes a front cavity with a long duct connecting the front space and the sound export.By the first resonant frequency of the front cavity,which makes the microspeaker’s output enhance in low frequency. In this thesis, the finite element analysis software is used to analyze the resonance frequency of the front cavity, and the frequency response of the micro-speaker combined with the front cavity is simulated. The electroacoustic analysis system CLIO is used to experiment. Then, through simulation analysis, the effects of duct length, duct cross-sectional area and front space size on the frequency response of the loudspeaker system are discussed. These results can be used as a reference for the design of the front cavity with duct.

並列關鍵字

micro-speakers ； finite element analysis ； front cavity ； resonant frequency ； sound pressure level

參考文獻

[1] E.W.SIEMENS,"IMPROVEMENT IN MAGNETO-ELECTRIC APPAPATUS, "UNITED STATES PATENT OFFICE,"1874

Google Scholar

[2] C.W.Rice and E.W.Kellogg, "Notes on the Development of a New Type of Hornless Loud Speaker, "Journal of American Institute of Electrical Engineers, vol.44,pp.461-480,1925.