微型喇叭聲學特性測試與模擬

Performance Testing and Simulation of Microspeakers

林致達(Chih-Da Lin)

指導教授 ： 劉興華

國立臺北科技大學/機電學院/車輛工程系所/碩士(2006年)

https://doi.org/10.6841/NTUT.2006.00281

摘要

本研究針對微型喇叭進行實驗與模擬兩項工作，利用音頻測試系統來量測微型喇叭單體的特性，透過阻抗曲線進而得知T-S參數，再將參數帶入模擬電路運算，如此即可預測喇叭的特性。由於T-S參數是決定一個喇叭特性的絕對指標之ㄧ，有了T-S參數則可預測喇叭的性能，但由於實驗的精準度將會影響T-S參數的可靠程度，參數的取得必須利用密閉空間的容積作為改變的測試條件，由於容積量以及喇叭於空間的密閉程度，這些條件的改變將有可能影響T-S的結果，本研究希望透過改變實驗條件，從中了解T-S參數的變化情形，尋找出一個適當的結果以及規則性。模擬項目可分為阻抗曲線(Impedance Curve)與頻率響應(Frequency Response)兩部分。此外，並觀察改變喇叭加裝後容積、前容積及出音孔對於喇叭特性改變的趨勢，藉由所得到的趨勢結果，方便未來對於微型喇叭音效的開發，有其規則性可依循。

關鍵字

微型喇叭 ； T-S參數 ； 阻抗曲線 ； 頻率響應

並列摘要

This research focus on testing and simulating on Microspeaker, by using frequency testing system to obtain the characteristics of Microspeaker. We received T-S parameter through impedance curve then brought parameter back to simulation of circuit model calculation therefore we can predict characteristics of Microspeaker. Due to T-S parameter is one of absolute index for deciding speaker’s characteristic therefore we can predict speaker’s performance by T-S parameter nonetheless accuracy of testing will affect reliability of T-S parameter. Getting T-S parameter must use changing volume of the sealed box to be testing conditions, due to sealed level of volume and space within speaker, those conditions will possibly affects result of T-S parameter. This research by changing testing conditions in order to understand conditions changed of T-S parameter. We are looking for appropriate results and regularity. There are two results of simulation. One is the impedance curve and the other one is frequency response. Furthermore, we will observe speaker’s characteristic tendency by adding rear volume, front volume and front vent to speaker. From what we found on result of tendency, we will follow its regularity for future Micro-Speaker development.

並列關鍵字

Microspeaker ； T-S parameter ； impedance curve ； frequency response

參考文獻

[19] S. S. Rao, Mechanical Vibrations, New Jersey, Pearson Prentice Hall, 2004, pp.239-243.

[4] J. Borwich, Loudspeaker and Headphone Handbook, SecondEdition, London, FocalPress, 1994.

[5] J. M. Eargle, Loudspeaker Handbook, New York, Chapman & Hall, 1997, pp.6-12.

[25] Sang-Moon Hwang, Member, IEEE, Gun-Yong Hwang, Joong-Hak Kwon, Hong-Joo Lee, and Beom-Soo Kang, "Performance Comparison Between Circular and Elliptical Type Microspeakers for Cellular Phones, " IEEE TRANSACTIONS ON MAGNETICS, VOL. 39, NO. 5, 2003,pp.3256.-3258

[28] Gun-Yong Hwang, Han-Gyoo Kim, Sang-Moon Hwang, and Beom-Soo Kang, Member, IEEE, "Analysis of Harmonic Distortion Due to Uneven Magnetic Field in a Microspeaker Used for Mobile Phones, " IEEE TRANSACTIONS ON MAGNETICS, VOL. 38, NO. 5, 2002, pp.2376-2378.