Abstract: A speaker seal for mounting a speaker within an automobile wherein the speaker is suspended in an opening in a body panel located substantially parallel to and spaced from a substantially contiguous trim panel with a corresponding opening, comprises a tubular member coaxially extending around the opening in the body panel and the opening in the trim panel and resiliently compressed between the panels. The seal forms an acoustic barrier between sound waves emitted by the speaker through the trim panel opening from sound waves emitted on the other side of the speaker.

Abstract: A transducer assembly for converting electrical energy into acoustical energy and vice versa in which a single multi-layer piezoelectric transducer drives (or is driven) a flat diaphragm secured at its edges in a housing. The piezoelectric transducer is a multi-layer wafer which is secured to a flexible sheet which in turn is secured over an aperture in the diaphragm. The piezoelectric multi-layer wafer has its central portion constrained from movement which increases its edgewise movement to twice its unconstrained value. The movement constraint is provided by a post on the housing which is cemented to a central aperture in the wafer. It has been found that there is a maximum ratio of the post diameter to the wafer diameter for optimum performance of the speaker.