An audio transducer is disclosed that has a piezoelectric driving element and a diaphragm configured as a flat, curvilinear plane. A lightweight, rigid bridge element connects the piezoelectric device to the diaphragm. Several bridge configurations are shown that emphasize or reduce various characteristics...http://www.google.fr/patents/US5652801?utm_source=gb-gplus-shareBrevet US5652801 - Resonance damper for piezoelectric transducer
