Model and estimation method for predicting the sound radiated by a horn loudspeaker – With application to a car horn

This paper deals with a new car horn device made of a sound synthesizer and an electrodynamic horn loudspeaker. It presents an one-dimensional model allowing to predict the loudspeaker efficiency and a specific method to estimate experimentally the model parameters. First, this model aims at reducing the time spent in the design process. Second it aims at correcting the sound emitted by the sound synthesizer in order that the listener hears the sound designed for creating the warning message. The study gives a survey of the vast loudspeaker literature. It is based on the conventional electroacoustic approach used for electrodynamic loudspeakers and on wave propagation models used for characterizing acoustic horns. The estimation of the model parameter values is performed using measurements of the electrical impedance of the loudspeaker and of the acoustic impedance of the horn. The model is assessed by comparing the calculated and measured electrical impedances and horn efficiencies. Results show that the model predicts well the horn efficiency up to 2500 Hz, the limitation being due to the horn radiation impedance modelization.

[1]  Michel Bruneau,et al.  Electrodynamic Loudspeaker with Baffle: Motional Impedance and Radiation , 1986 .

[2]  J. Kergomard.  General equivalent electric circuits for acoustic horns , 1988 .

[3]  Xavier Rodet,et al.  Radiation of a pulsating portion of a sphere: application to horn radiation , 2003 .

[4]  C. R. Hanna,et al.  The function and design of horns for loud speakers , 1924, Journal of the A.I.E.E..

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

[6]  Stephen McAdams,et al.  Perceptively based design of new car horn sounds , 2003 .

[7]  H. Levin.  On the radiation of sound from an unflanged circular pipe , 1948 .

[8]  J. Schwinger,et al.  On the Radiation of Sound from an Unflanged Circular Pipe , 1948 .

[9]  Andrew N. Norris,et al.  Acoustic radiation from a circular pipe with an infinite flange , 1989 .

[10]  Jean-Pierre Dalmont,et al.  Acoustic impedance measurement: Plane‐wave mode and first helical mode contributions , 1992 .

[11]  Emory Cook.  Binaural Disc Recording , 1953 .

[12]  Morten Knudsen,et al.  Low-Frequency Loudspeaker Models that Include Suspension Creep , 1993 .

[13]  W. Marshall Leach.  On the Specification of Moving-Coil Drivers for Low-Frequency Horn-Loaded Loudspeakers , 1978 .

[14]  Stephen McAdams,et al.  The sound quality of car horns: A psychoacoustical study of timbre , 2007 .

[15]  Bob H. Smith.  An Investigation of the Air Chamber of Horn Type Loudspeakers , 1953 .

[16]  Michael Makarski.  Determining Two-Port Parameters of Horn Drivers using only Electrical Measurements , 2004 .

[17]  Harry F. Olson.  Analysis of the Effects of Nonlinear Elements Upon the Performance of a Back Enclosed Direct Radiator Loudspeaker Mechanism , 1960 .

[18]  E. Eisner,et al.  Complete Solutions of the “Webster” Horn Equation , 1967 .

[19]  René Causse,et al.  Input impedance of brass musical instruments—Comparison between experiment and numerical models , 1984 .

[20]  Frank Fahy,et al.  Prediction and Measurement of the One-Parameter Behavior of Horns , 1991 .

[21]  John Vanderkooy,et al.  High-Efficiency Direct-Radiator Loudspeaker Systems , 2002 .

[22]  Hideo Suzuki.  Sound Radiation from a Concave or a Convex Dome in a Semi-Infinite Tube , 1983 .

[23]  Jean Kergomard,et al.  Analysis of higher order mode effects in an expansion chamber using modal theory and equivalent electrical circuits , 1989 .

[24]  Daniel J. Plach.  Design Factors in Horn-Type Speakers , 1953 .

[25]  Richard H. Small,et al.  Direct Radiator Loudspeaker System Analysis , 1971 .

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

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

[28]  Le Roux,et al.  Le haut-parleur electrodynamique : estimation des parametres electroacoustiques aux basses frequences et modelisation de la suspension , 1994 .

[29]  Wolfgang Klippel,et al.  Modeling the Nonlinearities in Horn Loudspeakers , 1996 .

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

[31]  John Vanderkooy,et al.  Direct-Radiator Loudspeaker Systems with High Bl , 2003 .

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

[33]  N. W. McLachlan,et al.  Sound Waves of Finite Amplitude in an Exponential Horn , 1935 .

[34]  Mark R. Gander,et al.  Historical Perspectives and Technology Overview of Loudspeakers for Sound Reinforcement , 2004 .

[35]  A G Webster,et al.  Acoustical Impedance and the Theory of Horns and of the Phonograph. , 1919, Proceedings of the National Academy of Sciences of the United States of America.

[36]  Julius O. Smith,et al.  Physical Modeling Using Digital Waveguides , 1992 .

[37]  W. J. Cunningham.  Non‐Linear Distortion in Dynamic Loudspeakers Due to Magnetic Effects , 1949 .

[38]  Harry F. Olson.  The Action of a Direct Radiator Loudspeaker with a Non‐Linear Cone Suspension System , 1944 .

[39]  Ph. Herzog,et al.  Modélisation basses fréquences d'un haut-parleur électrodynamique , 1994 .

[40]  T. SOMERVILLE,et al.  Applied Acoustics , 1958, Nature.

[41]  D. B. Keele.  Optimum Horn Mouth Size , 1973 .

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

[43]  David Clark,et al.  Computer Simulation of Horn-Loaded Compression Drivers , 1987 .

[44]  P. Béquin,et al.  Weak nonlinear propagation of sound in a finite exponential horn. , 2001, The Journal of the Acoustical Society of America.

[45]  Michael Makarski,et al.  Two-Port Representation of the Connection between Horn Driver and Horn , 2003 .

[46]  Stephen McAdams,et al.  Perception of the timbre of car horns , 2002 .

[47]  David J. Murphy.  Axisymmetric Model of a Moving-Coil Loudspeaker , 1993 .

[48]  Cornelis H. Slump,et al.  Modeling and Compensation of Nonlinear Distortion in Horn Loudspeakers , 1994 .

[49]  William J. Strong,et al.  Numerical method for calculating input impedances of the oboe , 1979 .

[50]  Richard H. Small.  Simplified Loudspeaker Measurements at Low Frequencies , 1971 .

[51]  Zdeněk Škvor.  Vibrating systems and their equivalent circuits , 1991 .

[52]  T. Mexia,et al.  Author ' s personal copy , 2009 .

[53]  D. B. Keele,et al.  Low-Frequency Loudspeaker Assessment by Nearfield Sound-Pressure Measurement , 1974 .

[54]  Tonni F. Johansen,et al.  On the Directivity of Horn Loudspeakers , 1994 .

[55]  Clifford A. Henricksen.  Phase Plug Modelling and Analysis: Circumferential Versus Radial Types , 1976 .