Abstract: A liquefied paper material is used as raw materials. A paper frame member 1 supporting a vibrating plate is paper-skimmed and formed. On paper-skimming and forming, a central hole for use in voice coils, air-release hole 1a releasing air pressure in a rear of the vibrating plate to outside due to vibration of the vibrating plate. A loudspeaker system is manufactured using the paper frame member 1.

Abstract: A motional feedback (MFB) signal control unit includes a vibration displacement calculating part which generates a vibration displacement detecting signal in response to the input of a vibration detecting signal from a vibration detecting coil of a speaker unit, a vibration speed calculating part which generates a vibration speed detecting signal in response to the input of the vibration detecting signal, a processed signal generating part which generates a feedback signal in response to the input of the vibration displacement signal and the vibration speed detecting signal, and an adder which adds the feedback signal to a sound signal outputted from a sound reproducing unit so as to input the sound signal to a driving voice coil of the speaker unit.

Abstract: A liquefied paper material is used as raw materials. A paper frame member 1 supporting a vibrating plate is paper-skimmed and formed. On paper-skimming and forming, a central hole for use in voice coils, air-release hole 1a releasing air pressure in a rear of the vibrating plate to outside due to vibration of the vibrating plate. A loudspeaker system is manufactured using the paper frame member 1.

Abstract: A liquefied paper material is used as raw materials. A paper frame member 1 supporting a vibrating plate is paper-skimmed and formed. On paper-skimming and forming, a central hole for use in voice coils, air-release hole 1a releasing air pressure in a rear of the vibrating plate to outside due to vibration of the vibrating plate. A loudspeaker system is manufactured using the paper frame member 1.

Abstract: A motional feedback (MFB) signal control unit includes a vibration displacement calculating part which generates a vibration displacement detecting signal in response to the input of a vibration detecting signal from a vibration detecting coil of a speaker unit, a vibration speed calculating part which generates a vibration speed detecting signal in response to the input of the vibration detecting signal, a processed signal generating part which generates a feedback signal in response to the input of the vibration displacement signal and the vibration speed detecting signal, and an adder which adds the feedback signal to a sound signal outputted from a sound reproducing unit so as to input the sound signal to a driving voice coil of the speaker unit.

Abstract: A speaker frame is constructed from dried paper pulp. Features in the speaker frame such as holes or slits are formed by carbonizing corresponding sections in the dried paper pulp and applying shear processing to remove the carbonized material. A carbonizing mold contains protrusions corresponding to the sections in the dried pulp to be carbonized. The result is a high quality speaker frame that is biodegradable and can be produced economically.

Abstract: In a speaker device equipped with a crossover network according to the present invention, which is used mainly in an automobile sound reproducing system or the like, a capacitor for the crossover network is accommodated within a pole piece of the speaker unit itself to eliminate bulkiness based on an external form of the network unit, thereby permitting the speaker device to be installed in a short time during manufacture of a vehicle or the like.

Abstract: A damper for a loudspeaker has an improved linearity of the amount of strain caused by the vibrational energy to vibrational energy exerted on the damper to enable the loudspeaker to reproduce sounds in a high fidelity. The damper is formed such that the modulus of elasticity with respect to a direction perpendicular to the surface of the damper is uniform on a circle with its center at the center of the damper, and portions respectively on concentric circles with their centers at the center of the damper are different in modulus of elasticity with respect to a direction perpendicular to the surface of the damper from each other.