LOUDSPEAKER FEM MODELING: CHARACTERIZATION OF CRITICAL ASPECTS IN ACOUSTIC IMPEDANCE MEASURE THROUGH ELECTRICAL IMPEDANCE

A loudspeaker can be seen as a device coupling different acoustic, mechanic and electric systems by a series of impedance adaptations. A simple model can thus allow the extraction of the acoustic impedance seen by the speaker membrane from measuring the electric impedance of the device, in principle valid through a wide frequency range if some assumptions are made on mechanical modes and on the strictly electric components. This should allow, using the loudspeaker and similar devices, to perform acoustic impedance measurements. Still, many difficulties arise when trying to apply straightforwardly this method. We then aim to setup this problem in a FEM framework, to characterize and study separately its critical aspects and provide possible methods to overcome them.