Mitsubishi Denki Kabushiki Kaisha

Mitsubishi Electric Corporation

Senju Metal Industry Co., Ltd.

Seiki Suzuki

Noboru Kyouno

Satoru Inoue

Mutsuo Sekiya

Kohei Teramoto

Takahisa Aoyagi

Tsuyoshi Nakada

Jun Yoshida

Isamu Osawa

Ryoichi Hamahashi

Hideki Tokimoto

Masahumi Seino

Ippei Akagi

A casing for covering an outer yoke is provided; an acoustic cavity is formed by this casing; a diaphragm and the outer surface of a side wall of the outer yoke; a second elastic member is provided to join the outer circumferential edge of the casing to the outer circumferential edge of the diaphragm without any gap therebetween; this second elastic member includes pores formed by foaming and made of a material whose elastic modulus is smaller than that of a first elastic member; and pores communicating through from the back surface of the second elastic member, that is the inner side of the casing, to the front surface that is the opposite side of the back surface are eliminated.

Electrodynamic sound-emitting device

A complementary pulse width modulation circuit is composed of a signal generating circuitfor generating first and second pulse width modulation signals (PWM#and PWM#) that are complementary to each other from an input signal (IN) in response to a sampling synchronous signal (Sample) generated in synchronization with a clock (CLK); and a signal output circuitfor combining a positive signal and a negative signal of the first pulse width modulation signal (PWM#) generated by the signal generating circuit, and for combining the first pulse width modulation signal (PWM#) combined with the second pulse width modulation signal (PWM#), followed by outputting.

Digital to-analog converter

A speaker system includes a plurality of double-voice-coil speaker units fitted to a closed type cabinet and connected in parallel with each other so that first voice coils are connected to each other at the same polarities, and second voice coils are connected to each other at the same polarities, and a single impedance compensating circuit is connected in series to the second voice coils for making the input impedance as the speaker system constant.

Speaker system

In a speaker system employing a bass reflex or Kelton type cabinet intends to solve deterioration in efficiency of a speaker caused by an increase in impedance otherwise occurring on both sides of the antiresonance frequency, and to improve the sound radiating efficiency. The speaker system comprises a plurality of dual-voice-coil speaker units (20) which are attached to a bass reflex or Kelton type cabinet (50) and made up of first voice coils (21) connected in parallel to each other with the same polarities joined into one terminal and second voice coils (22) connected in parallel to each other with their same polarities joined into one terminal, and one impedance compensation circuit (10) connected in series to the plurality of second voice coils, which are connected in parallel to each other, for thereby keeping constant the input impedance as a parameter of the speaker system.

Growing community of inventors

Tokyo, Japan

Seiki Suzuki