Faurecia Clarion Electronics Co., Ltd.

Tetsuo Watanabe

Yasuhiro Fujita

Akiko Nakamura

Chihiro Kuwayama

A filter generation apparatus includes: a coefficient calculation unit that performs IFFT on a frequency characteristic of a frequency domain filter and calculates a filter coefficient of a linear phase FIR filter; a conversion unit that converts the filter coefficient to a filter coefficient of a minimum phase FIR filter; a coefficient generation unit that generates a filter coefficient of an approximation filter by executing cut-out processing to a filter length set by a filter length setting unit and rounding processing performed by a window function on the filter coefficient; an error calculation unit that calculates an error of a frequency characteristic corresponding to the approximation filter with respect to the frequency characteristic of the frequency domain filter; and a filter storage unit that stores the filter coefficient therein as a filter coefficient that specifies a new filter when the error is equal to or less than a predetermined threshold value.

Filter generation apparatus and recording medium

An acoustic device includes: a generating unit that generates a monaural signal on the basis of a left stereo signal and a right stereo signal in a low frequency band; an extracting unit that extracts a stereo component for an L-channel and a stereo component for an R-channel on the basis of a left stereo signal and a right stereo signal in a high frequency band; a first combining unit that combines the monaural signal and the stereo component for the L-channel; and a second combining unit that combines the monaural signal and the stereo component for the R-channel.

Acoustic device with first sound outputting device for input signal, second outputting device for monaural signal and L-channel stereo component and third sound outputting device for monaural signal and R-channel stereo component

A signal processing device according to aspects of the present disclosures comprises a measuring section configured to measure an impulse response between each of a plurality of speakers and a predetermined listening position, a Fourier transformer configured to obtain a frequency spectrum corresponding to each of the plurality of speakers by applying a Fourier transform, a phase adjustment amount calculator configured to calculate a phase adjustment amount for each frequency, a band detector configured to detect a leading phase band, a phase converter configured to convert a phase of the leading phase band to a lagging phase, and a filter coefficient generator configured to generate a filter coefficient based on the phase adjustment amount after conversion by the phase converter.

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Saitama, Japan

Tetsuo Watanabe