AES Fall Convention 2022

Piezoelectric actuators offer advantages in terms of weight and form-factor when compared with traditional inertial exciters used to drive flat-panel loudspeakers. Unlike inertial exciters, piezoelectric actuators induce vibrations in the panel by generating bending moments at the actuator edges. Models for piezoelectric excitation are developed, and it is shown that piezoelectric actuators are most effective at driving resonant modes whose bending half-wavelength is the same size as the actuator dimensions, giving a natural boost to the high-frequency response. Flat-panel loudspeaker design techniques such as the modal crossover method, and the corresponding array layout optimization are adapted using the model for the response of piezo-driven panels. The adapted design techniques are shown to eliminate the isolated, low-frequency bending modes responsible for reduced sound quality on a prototype panel speaker.