微型揚聲器分析評估與設計最佳化

Abstract

本計畫主要目的在於微型揚聲器以及音響空間之電聲系統的分析、設計與評估。 目前關於揚聲器之分析與評估之軟體與設備，主要都針對大型揚聲器，對於微型 揚聲器這些分析的軟硬體並無法做分析。近年來，微型揚聲器被廣泛應用在3C 產品上，已成為3C 產品之重要元件，如行動電話、PDAs 以及MP3 等，因此微 型揚聲器高度值得從事系統分析與設計之開發研究。本計畫有四個特點單元，第 一個單元為微型揚聲器參數鑑別，經由測試箱法來鑑別出微型揚聲器的機電聲類 比參數。第二個單元為微型揚聲器之動態響應與音響空間之機電聲模擬。第三個 單元為揚聲器性能評估，包括：阻抗、頻率響應、感度、效率、指向性以及諧波 失真等指標。第四個單元為微型揚聲器之最佳化設計，由最佳化分析求得微型揚 聲器以及音響空間之最佳設計參數，以期能設計出微型揚聲器最佳聲學效能以及 最小諧波失真。

The goal of this project is to establish the analysis, design and evaluation of miniature loudspeaker systems. At present time, existing analysis and design techniques are mostly intended for large lousspeakers. These techniques are not directly applicable to miniature loudspeakers. In recent years, miniature loudspeakers are key components of many 3C products especially for portable devices such as mobile phones, PDAs, MP3, etc. It is highly desirable to develop a systematic analysis and design procedure appropriate for miniature loudspeakers. The study features 4 modules. The first module is the parameter identification module for estimating the electroacoustic parameters of loudspeaker via test-box method. The second module is the response simulation module for predicting the dynamic response of loudspeaker and the associated acoustic housing on the basis of electro-mechano-acoustic (EMA) analogous circuits. The third module is the evaluation module for assessing loudspeakers by awy of several performance indices, including voice-coil impedance, frequency response, sensitivity, efficiency, directivity and harmonic distortion. The fourth module is the design optimization module for finding the optimal parameters of miniature loudspeakers the associated acoustic housing that best reconcile the output performance and distortion limit.