MINIATURE SPEAKER WITH INTEGRATED SIGNAL PROCESSING ELECTRONICS

摘要

A miniature speaker having built-in electronic components for providing a feedback signal for dynamically adjusting acoustical parameters of the miniature speaker. The miniature speaker includes in the preferred embodiment a housing, a magnetic circuit, a coil, a diaphragm, a sensor, and an electronic circuit. The sensor is formed by the metallized portion of the diaphragm and the metallized portion of the housing cover. The two metallized portions form a plate capacitor, and as the diaphragm vibrates, the capacitance of the plate capacitor changes. These changes are converted into a feedback signal which is combined with the input audio signal in an electronic circuit mounted directly on the diaphragm and which drives the speaker while adjusting acoustical parameters, such as resonance, distortion, and sensitivity. The feedback signal can also be used to protect the active components of the miniature speaker against mechanical stress, thereby prolonging the lifetime of the speaker.