Ranking of the nonlinearities of electrodynamic loudspeakers

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.

[1]  A. Kaizer.  Modeling of the nonlinear response of an electrodynamic loudspeaker by a Volterra series expansion , 1987 .

[2]  Wolfgang Klippel,et al.  Tutorial: Loudspeaker Nonlinearities-Causes, Parameters, Symptoms , 2006 .

[3]  W. Marshall Leach,et al.  Loudspeaker Voice-Coil Inductance Losses: Circuit Models, Parameter Estimation, and Effect on Frequency Response , 2002 .

[4]  Guy Lemarquand,et al.  Transient modal radiation of axisymmetric sources: Application to loudspeakers , 2010 .

[5]  Julian R. Wright.  An Empirical Model for Loudspeaker Motor Impedance , 1990 .

[6]  Romain Ravaud,et al.  Magnetic pressure and shape of ferrofluid seals in cylindrical structures , 2009 .

[7]  Guy Lemarquand,et al.  Motor Nonlinearities in Electrodynamic Loudspeakers: Modelling and Measurement , 2009 .

[8]  B. Merit,et al.  In Pursuit of Increasingly Linear Loudspeaker Motors , 2009, IEEE Transactions on Magnetics.

[9]  B. Castagnede,et al.  Ironless and Leakage Free Voice-Coil Motor Made of Bonded Magnets , 2008, IEEE Transactions on Magnetics.

[10]  Mark R. Gander.  Moving-Coil Loudspeaker Topology as an Indicator of Linear Excursion Capability , 1981 .

[11]  Romain Ravaud,et al.  Ironless Loudspeakers with Ferrofluid Seals , 2008 .

[12]  Guy Lemarquand,et al.  An Ironless Large Displacement Flat Piston Loudspeaker , 2009 .

[13]  Andrzej Dobrucki,et al.  Nontypical Effects in an Electrodynamic Loudspeaker with a Nonhomogeneous Magnetic Field in the Air Gap and Nonlinear Suspensions , 1994 .

[14]  Romain Ravaud,et al.  Time-varying non linear modeling of electrodynamic loudspeakers , 2009 .

[15]  Mark R. Gander.  Dynamic Linearity and Power Compression in Moving-Coil Loudspeakers , 1986 .

[16]  Michel Bruneau,et al.  Nonlinear Intermodulation of Two Coherent Acoustic Progressive Waves Emitted by a Wide-Bandwidth Loudspeaker , 2008 .

[17]  Romain Ravaud,et al.  MODELLING AN IRONLESS LOUDSPEAKER BY USING THREE-DIMENSIONAL ANALYTICAL APPROACHES , 2009 .

[18]  Hideo Suzuki,et al.  Radiation and Diffraction Effects of Convex and Concave Domes in an Infinite Baffle , 1980 .

[19]  John Vanderkooy,et al.  A Model of Loudspeaker Driver Impedance Incorporating Eddy Currents in the Pole Structure , 1989 .

[20]  Wolfgang Klippel,et al.  Dynamic Measurement and Interpretation of the Nonlinear Parameters of Electrodynamic Loudspeakers , 1990 .

[21]  Honorata Hafke,et al.  Nonconscious Control of Voice Intensity During Vocalization , 2009 .

[22]  David Clark.  Precision Measurement of Loudspeaker Parameters , 1997 .

[23]  Neville Thiele,et al.  Loudspeakers in Vented Boxes: Part 1 , 1971 .

[24]  C. J. Nederveen,et al.  RADIATION IMPEDANCE OF TUBES WITH DIFFERENT FLANGES: NUMERICAL AND EXPERIMENTAL INVESTIGATIONS , 2001 .

[25]  G. Lemarquand.  Ironless Loudspeakers , 2007, IEEE Transactions on Magnetics.

[26]  R. Ravaud,et al.  Design of Ironless Loudspeakers with Ferrofluid Seals: Analytical Study Based on the Coulombian Model , 2009 .