A method of characterising performance of audio loudspeakers for linear alternator applications in low-cost thermoacoustic electricity generators

Zhibin Yu, Patcharin Saechan, AJ Jaworski

Research output: Contribution to journalArticle

29 Citations (Scopus)


This paper investigates the feasibility of using commercially available loudspeakers as low-cost linear alternators for thermoacoustic applications, to convert acoustic power to electricity. The design of a purpose built experimental apparatus, in which a high intensity acoustic wave is induced by using a high power woofer, is described. The rig is used to excite loudspeakers (referred here as “alternators”) under test, while a pair of microphones and a laser displacement sensor are used to enable acoustic power measurements. The paper presents a case study in which characteristics of acoustic-to-electric energy conversion of a candidate loudspeaker (alternator) – selected from the viewpoint of general performance, as well as parameters such as: high force factor, low electrical resistance and low mechanical loss – are measured. The measurements of acoustic power absorbed by the alternator and the electric power extracted from it by the load resistor, which allow estimating acoustic-to-electric efficiencies, are presented. The alternator has been tested at different operating frequencies, cone displacements and load resistance values. The measurement results are discussed and compared in detail with the calculations based on the linear acoustics model.
Original languageEnglish
Pages (from-to)260-267
Number of pages8
JournalApplied Acoustics
Issue number5
Early online date28 Dec 2010
Publication statusPublished - Apr 2011
Externally publishedYes


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