Hydrostatic speaker and speaker driver

Abstract

A hydrostatic speaker includes an oscillator, a partition diaphragm disposed in the oscillator to divide the oscillator into two chambers, at least one of which chambers serves as a fluid chamber to cause the partition diaphragm to vibrate in response to external signals from a source, an acoustic sound radiation core connected with the partition diaphragm via a rod, a sensor for detecting fluid pressure in the fluid chamber and another sensor for detecting a movement of the partition diaphragm. The hydrostatic speaker is provided with a speaker driver which includes a fuild pressure controller connected to a pressure source for controlling the fluid pressure in the fluid chamber, and a control amplifier for controlling the fluid pressure controller in accordance with the external signals. Signals detected by the pressure sensor and the position sensor are respectively input as feedback signals to the control amplifier in order to improve controllability, to reduce noises due to pressure fluctuation in the pressure source, and to improve a neutral positioning of the partition diaphragm. The hydrostatic speaker can radiate super low-frequency sound, which has been considered difficult by conventional speakers.