4aEA6. A simplified approach to a nonlinear loudspeaker modeling.

Session: Thursday Morning, June 19

Author: Earl Geddes
Location: GedLee and Assoc., 1388 Medinah Dr., Itasca, IL 60143


Exact solutions of the nonlinear equations for a loudspeaker are extremely difficult to solve as they involve Volterra series expansions and higher-order system functions and impulse responses [A. R. Kaiser et al., J. Audio Eng. Soc. 35, 421--433]. Indeed, these complex methods are required for exact system simulations, however, they can be greatly simplified with a reasonable assumption about the system. By assuming that the distortion (or nonlinearity) is not so large that it causes an excessive amount of distortion, say about 20% THD, a vastly simplified approach can be developed. It is not always the case that this near-linear assumption can be made, but clearly, it should be accurate for higher performance units. This presentation will show how to use an algebra processor (Maple) to develop these simplified predictions given the nonlinearities of the parameters. These equations will then be used to show the effect that various loudspeaker enclosure designs have on the distortion of a given (typical) loudspeaker using a commercially available software package written by the author.

ASA 133rd meeting - Penn State, June 1997