Piezoelectric Loud Speakers
A. L. Williams · Journal of the Society of Motion Picture Engineers · 1935
Recent progress in piezoelectric loud speakers for theater use, including a new unit for upper registers, is described. Frequency-response characteristics of this unit alone and in combination are discussed and demonstrated. — The character of the load upon the output circuit, and its effect upon the efficiency and the production of satisfactory response in the low and high registers, are discussed.