Abstract
The aim of this paper is to present a way of ranking the nonlinearities of electrodynamic loudspeakers. For this purpose, we have constructed a nonlinear analytic model which takes into account the variations of the small signal parameters. The determination of these variations is based on a very precise measurement of the electrical impedance of the electrodynamic loudspeaker. First, we present the experimental method to identify the variations of these parameters, then we propose to study theoretically the importance of these nonlinearities according to the input level or the input frequency. We show that the parameter which creates most of the distortions is not always the same and depends mainly on both the input level and the input frequency. Such results can be very useful for optimization of electrodynamic loudspeakers.Keywords:
electrodynamic loudspeaker, nonlinearities, small signal parameters, nonlinear modelingReferences
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13. Lemarquand G. (2007), Ironless loudspeakers, IEEE Trans. Magn., 43, 8, 3371–3374.
14. Lemarquand G., Bruneau M. (2007), Large bandwith loudspeaker emitting coherent acoustic waves: nonlinear inter-modulation effects, J. Audio Eng. Soc., 56, January, 36–44.
15. Merit B., Lemarquand G., Lemarquand V. (2009a), In pursuit of increasingly linear loudspeaker motors, IEEE. Trans. Mag., 45, 6, 2867–2870.
16. Merit B., Lemarquand V., Lemarquand G., Dobrucki A. (2009b), Motor nonlinearities in electrodynamic loudspeakers: modelling and measurement, Archives of Acoustics, 34, 4, 407–418.
17. Quaegebeur N., Chaigne A., Lemarquand G. (2010), Transient model radiation of axisymmetric sources: application to loudspeakers, Applied Acoustics, 71, 4, 335–350.
18. Ravaud R., Lemarquand G., Lemarquand V., Depollier C. (2008), Ironless loudspeakers with ferrofluid seals, Archives of Acoustics, 33, 4 (Supplement), 53–58.
19. Ravaud R., Lemarquand G. (2009a), Modelling an ironless loudspeaker by using threedimensional analytical approaches, Progress in Electromagnetics Research, PIER 91, 53–68.
2. Clark D. (1997), Precision measurement of loudspeaker parameters, J. Audio Eng. Soc., March, 129–141.
3. Dalmont J., Nederveen C., Joly N. (2001), Radiation impedance of tubes with different flanges: numerical and experimental investigations, J. of Sound and Vibration, 244, 3, 505– 534.
4. Dobrucki A. (1994), Nontypical effects in an electrodynamic loudspeaker with a nonhomogeneous magnetic field in the air gap and nonlinear suspension, J. Audio Eng. Soc., 42, 565–576.
5. Gander M.R. (1981), Moving-coil loudspeaker topology as an indicator of linear excursion capability, J. Audio Eng. Soc., 29.
6. Gander M.R. (1986), Dynamic linearity and power compression in moving-coil loudspeaker, J. Audio Eng. Soc., September, 627–646.
7. Gille J.C., Decaulne P., Pelegrin M. (1981), Systemes asservis non lineaires, Bordas Editeur, Paris, France.
8. I.E.C, Sound. System. Equipment, Part 5: Loudspeaker, Edition 3.1, 11-09-2007.
9. Kaizer A.J.M. (1987), Modeling of the nonlinear response of an electrodynamic loudspeaker by a Volterra series expansion, J. Audio Eng. Soc., 35, June, 421–433.
10. Klippel W. (1990), Dynamic measurement and interpretation of the nonlinear parameters of electrodynamic loudspeakers, J. Audio Eng. Soc., 38, 944–955.
11. Klippel W. (2006), Loudspeaker nonlinearities – cause, parameters, symptoms, J. Audio Eng. Soc., 54, 907–939.
12. Leach W. (2002), Loudspeaker voice-coil inductance losses: Circuit models, parameter estimation and effect on frequency response, J. Audio Eng. Soc., 442–449.
13. Lemarquand G. (2007), Ironless loudspeakers, IEEE Trans. Magn., 43, 8, 3371–3374.
14. Lemarquand G., Bruneau M. (2007), Large bandwith loudspeaker emitting coherent acoustic waves: nonlinear inter-modulation effects, J. Audio Eng. Soc., 56, January, 36–44.
15. Merit B., Lemarquand G., Lemarquand V. (2009a), In pursuit of increasingly linear loudspeaker motors, IEEE. Trans. Mag., 45, 6, 2867–2870.
16. Merit B., Lemarquand V., Lemarquand G., Dobrucki A. (2009b), Motor nonlinearities in electrodynamic loudspeakers: modelling and measurement, Archives of Acoustics, 34, 4, 407–418.
17. Quaegebeur N., Chaigne A., Lemarquand G. (2010), Transient model radiation of axisymmetric sources: application to loudspeakers, Applied Acoustics, 71, 4, 335–350.
18. Ravaud R., Lemarquand G., Lemarquand V., Depollier C. (2008), Ironless loudspeakers with ferrofluid seals, Archives of Acoustics, 33, 4 (Supplement), 53–58.
19. Ravaud R., Lemarquand G. (2009a), Modelling an ironless loudspeaker by using threedimensional analytical approaches, Progress in Electromagnetics Research, PIER 91, 53–68.
