Masao Noro

Device for driving vibration source

An excitation device vibration source comprising: a source (10) for generating sound musical tone signals; a sequencer (40) for driving and controlling the sound source (10) based on sequence data, namely music data; means (22) for driving a source (24, 26) of vibration; and a switching means (42) to turn on or off a signal supplied to the excitation means (22) under control of the sequencer (40), in which the sequencer (40) is adapted to control the switching means (42 ) based on timing data included in the sequence data.

Acoustic apparatus and driving apparatus constituting the same

An acoustic apparatus comprises a cabinet, and a loudspeaker unit and a driving apparatus disposed in the cabinet. The acoustic apparatus is driven by an external power amplifier which normally constant-voltage-drives a conventional loudspeaker. The driving apparatus has a power amplifier circuit and a transfer function control circuit, and drives the loudspeaker unit in cooperation with the external power amplifier. The driving apparatus generates an electric energy corresponding to an increase in energy from that which is required in a normal constant-voltage-driving, the increase being produced by an operation of the transfer function control circuit, and the generated energy is inputted to the loudspeaker unit. By means of the above, when the acoustic apparatus is driven by the external power amplifier, an internal resistance of the loudspeaker unit is substantially cancelled or reduced, and an improvement of the electro-acoustic transducing characteristics of the loudspeaker unit or a loudspeaker system is achieved.

Sound field expanding apparatus with improved tone control system

A sound field processor having amplitude/phase conversion circuits for left and right channels of a stereophonic signal. The amplitude/phase conversion circuits for left and right channels have substantially the same circuit structure. Each of the amplitude/phase conversion circuits has an inversion amplifier, an amplitude/phase characteristic changing circuit that changes amplitude and phase characteristics of an output from the inversion amplifier, and a feedback device that add outputs from the amplitude/phase characteristic changing circuit and outputs from the inversion amplifier to an input signal to generate a sum signal and feed back the sum signal to the inversion amplifier. An output from the inversion amplifier for the left channel and an output from the amplitude/phase characteristic changing circuit for the right channel are added by a first adder device. An output from the inversion amplifier for the right channel and an output from the amplitude/phase characteristic changing circuit for the left channel are added by a second adder device. An output from the amplitude/phase characteristic changing circuit is fed back through a feedback path between an output and an input of the amplitude/phase characteristic changing circuit. A D/A converter is interposed in the feedback path to adjust the level of the feedback signal to perform bass control.