Motional feedback loudspeaker apparatus having a coupling member for connecting a voice coil bobbin with a detecting coil bobbin

摘要

A loudspeaker apparatus includes a diaphragm, a driving part driving a diaphragm, a detecting part and a coupling member. The driving part includes a voice coil bobbin mounted on the diaphragm, a voice coil wound about the voice coil bobbin and a driving magnetic circuit generating a driving power driving the diaphragm along with the voice coil. The detecting part has its terminal voltage changed responsive to the rate of displacement of the diaphragm or the voice coil bobbin. The detecting part has a detection bobbin about which a detection coil is wound and a detection magnetic circuit for detecting displacement of the diaphragm or the voice coil bobbin along with the detection coil. The connecting member is cup-shaped and formed of a liquid crystal polymer material. The coupling member has its surface smoothly curved from the outer lateral side towards the center. The coupling member has one of the voice coil bobbin and the detection bobbin mounted on its outer peripheral surface and the other of the voice coil bobbin and the detection bobbin mounted on its mid portion. The driving part and the detection part are arranged coaxially. A detection signal of the detecting part is fed back to the driving part.