Virtual Prototyping of Electrodynamic Loudspeakers by Utilizing a Finite Element Method

Abstract

To speed up the development of electrodynamic loudspeakers, computer tools have to be applied. With appropriate computer simulations, the costly and lengthy fabrication of prototypes, as required within conventional experimental design, can be reduced tremendously. Present computer modeling tools are mainly based on equivalent circuit representations. The main drawback of these models, however, stems from the fact that the circuit element parameters have to be measured on a prototype, first. Therefore, the need for appropriate numerical simulation tools based on finite element method (FEM) arises, since as input parameters they suffice with geometrical and material data. However, present finite element tools suffer from their incompleteness in respect to full field couplings and nonlinear features. In this paper, a new finite element scheme is introduced and its utilization within the computer-aided design of electrodynamic loudspeakers is demonstrated. This scheme allows the precise and efficient calculation of the electromagnetic, mechanical and acoustic fields, including their couplings. Furthermore, nonlinear effects in the mechanical behavior of the spider as well as magnetic nonlinearities due to the nonhomogeneity of the magnetic field are taken into account.