Vibration Analysis and Its Application to the Design of Flat Plane Speakers Incorporating the Velocity Feedback Compensation

Abstract

Major trends in the cone type dynamic speaker design are the realization of the uniresonance cones. On the contrary, the flat plane speaker has wide sound radiation area making its tone characteristics preferable to the general type speakers, however, the main defects of the flat speakers are their multiresonance of the vibrating membrane. After analysis of the flat membrane vibration problems, driving methods to excluded the multiresonance were found; that is, if the membrane were to be driven by the continuously distributed force proportionate to the fundamental vibration mode amplitude of the membrane, no multiresonance is proven to take place. While, within some restricted frequency range, the uniresonance is expected by the some discrete concentrated driving points. This driving method was applied to some cases taking account of various boundary conditions, and the method was applied to some cases taking account of various boundary conditions, and the experiments resulted in good cancellation of the multiresonance. This paper includes the improving methods of flat speakers distortion by the use of the velocity feedback compensation.