An apparatus of acoustic signals, especially an electromagnetic horn. (Machine-translation by Google Translate, not legally binding)

摘要

An acoustic signal device, in particular an electromagnetic horn with an inflected membrane, which covers a box and is fixed on the edge of the box, a membrane which, in addition to a fundamental oscillation, radiates at least one harmonic, characterized in that the the membrane has, in the vicinity of its fastening edge, a surrounding stamp, which rises at an angle of at least 30º, forming a sharp edge with the main plane of the membrane. (Machine-translation by Google Translate, not legally binding)