Loudspeaker analysis -- 2D/3D Magnetostatic

A basic analysis of a loudspeaker design consists of analyzing the magnetostatic properties of a 2D axisymetric design. In certain cases, 2D analysis is insufficient because of symmetry breaking features, for example, segmented magnets. In this case, a 3D model is needed. The same analyses can be performed in 3D as with the 2D analysis package.

The following diagrams show a typical 2D loudspeaker design in MagNet and the resulting contoured and shaded flux density fields, some 3D views, and the results of parameterization to the geometry of the model.

Results

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A countour plot.

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A shaded flux density plot for identification of magnetically saturated regions.

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An example of a segmented magnet loudspeaker, as a 3D model, is shown here.

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This illustration displays the same 3D model, with the top plate removed, to show the gap in the magnet.

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A useful tool that can be used with any of the solvers is the parameterization of the loudspeaker. Parameterization can be used to vary geometries, material properties, voice coil positions and many other quantities as well.

In this example, the original speaker dimensions were parameterized to allow the user to modify the speaker dimensions, without completely rebuilding the speaker model.

The MagnetOR (magnet outer radius) parameter is changed.

 

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The resulting change to the geometry.