the energy storage and transmission capabilities of a capacitance - type electroacoustical transducer are increased and the cost of producing such a transducer can be decreased by employing a thin , dielectric coating material between the electrically conductive diaphragm and backplate of said transducer , and by locating the electrically conductive diaphragm support layer on what would otherwise be an exposed outer diaphragm surface to protect same from physical as well as environmental damage .