Kabushikikaisha Kenwood

Trio Kabushiki Kaisha

Namiki Precision Jewel Co., Ltd.

Masakatsu Sakamoto

Shiro Iwakura

Kaoru Yamazaki

Yoichi Yaguchi

Hiroaki Toshima

Shuhei Ohta

Tsugio Sato

Kenji Ogi

Yutaka Mae

A nondirectional acoustic generator includes two acoustic generator units which are disposed facing each other as near as possible to the extent that diaphragms thereof do not become in contact with each other, drive units of the acoustic generator units being connected in series or in parallel to drive the acoustic generator units in phase and generate air compression sound waves which are radiated in the circumferential direction of the diaphragms. A speaker system includes a plurality of nondirectional acoustic generators coaxially disposed so as to align the centers of respective diaphragms and make the phases at sound generating areas coincident with each other.

Nondirectional acoustic generator and speaker system

A speaker cone plate is provided with an inorganic surfacial hard layer formed at least on a face of a metal substrate and is subjected to a reinforcing treatment by hot isostatic pressing, wherein the surfacial hard layer may be composed of a carbide, an oxide, a borie or a phosphide or may be formed by plasma thermal spraying of an inorganic substance containing silicon nitride whiskers or silicon carbide whiskers.

Speaker cone plate and method of forming

A method of forming diamond-like carbon layer which is advantageously adaptable as a coating layer on acoustic diaphragms. In the method, carbon vaporized out of solid carbon source is deposited onto the surface of the diaphragm as the coating layer in the atomosphere of catalystic gas, for instance, H.sub.2 +Ar or H.sub.2 of about 10.sup.-4 Torr. The deposited carbon layer on the surface of the diaphragm is an amorphous carbon of inclusion of hybridized orbital SP.sup.2 bond and hybridized orbital SP.sup.3 bond and crystalline carbon particles of hybridized orbital SP.sup.3 bond dispersed in the amorphous carbon, or an amorphous carbon of inclusion of hybridized orbital SP.sup.2 bond and hybridized orbital SP.sup.3 bond.

Method for forming a hard carbon thin film on article and applications

A method of forming diamond-like carbon layer which is advantageously adaptable as a coating layer on acoustic diaphragms. In the method, carbon vaporized out of solid carbon source is deposited onto the surface of the diaphragm as the coating layer in the atmosphere of catalystic gas, for instance, H.sub.2 +Ar or H.sub.2 of about 10.sup.-4 Torr. The deposited carbon layer on the surface of the diaphragm is an amorphous carbon of inclusion of hybridized orbital SP.sup.2 bond and hybridized orbital SP.sup.3 bond and crystalline carbon particles of hybridized orbital SP.sup.3 bond dispersed in the amorphous carbon, or an amorphous carbon of inclusion of hybridized orbital SP.sup.2 bond and hybridized orbital SP.sup.3 bond.

A loudspeaker system has a cabinet in which a loudspeaker is mounted, the cabinet supporting therein a hollow duct which provides sound communication between the exterior and interior of the cabinet. A standing wave prevention member made of a sound absorbent material is disposed within the duct in spaced relation thereto, the member being smaller in volume than the duct.

Loudspeaker system

In a bass-reflex type speaker system, in which sound signal waves radiating from the back of a speaker within a cabinet are emitted out through a hollow duct while the phase of the sound signal wave is reversed, the improvement comprising at least one dividing plate secured within the hollow duct and disposed parallel to the longitudinal direction of the duct or a hollow pipe with a diameter smaller than that of the duct, the hollow pipe being coaxially disposed within the hollow duct where the pipe may be made of sound absorbing material.

Growing community of inventors

Tokyo, Japan

Masakatsu Sakamoto