Yamaha Corporation

Nippon Gakki Seizo Kabushiki Kaisha

Tsugio Ito

Ryuichiro Kuroki

Hisashi Okada

Kenshiro Aizawa

Ryuuji Wakatsuki

Naohiro Emoto

Shigeru Fujita

A reverberation apparatus is designed for generating a reverberation sound from an input sound with use of an impulse response based on an instruction. In the reverberation apparatus, a first storage section stores first impulse response data representative of a first impulse response. A second storage section stores second impulse response data representative of a second impulse response which is different from the first impulse response represented by the first impulse response data. A new data creating section operates based on the first impulse response data and the second impulse response data for creating new impulse response data representative of a new impulse response in accordance with the instruction. A reverberation sound generating section generates reverberation sound data representative of the reverberation sound by filtering input sound data representative of the input sound with use of the new impulse response data, such that the generated reverberation sound is featured by the new impulse response.

Reverberation sound generating apparatus

Measuring gate pulse is generated that rises in synchronism with one of first and second clock signals and falls in synchronism with the other of the first and second clock signals. Then, a pulse width of the generated measuring gate pulse is measured by counting clock pulses higher in frequency than the first and second clock signals. When counted values indicative of respective pulse widths of an adjacent pair of the measuring gate pulses generated in succession coincide with each other, it is determined that the frequencies of the first and second signal are the same, but when the counted values of the adjacent pair of the measuring gate pulses do not coincide with each other, it is determined that the frequencies of the first and second signal are not the same.

Clock-synchronism evaluating apparatus and method

A data clock generator, a data clock generating method and a storage medium therefor are provided, which make it possible to reduce burden on a PLL circuit and substantially reduce jitter in the generated data clock signal, as well as achieve a sufficiently wide lock range of the PLL circuit. Data packets are supplied, which include at least a plurality of data samples and time stamps which are smaller in number than the number of the plurality of data samples. Time samples are generated, respectively, for the data samples from the time stamps of the supplied data packets. A PLL circuit generates a data clock signal based on the time samples for the respective data samples.

Data clock generator, data clock generating method, and storage medium therefor

An impulse response measuring method uses an echo chamber in which a speaker and a microphone are arranged. The speaker produces measured sounds, used for measurement of impulse response, which are detected by the microphone. The microphone produces sound signals corresponding to the measured sounds. An analysis device calculates impulse response of the echo chamber based on the sound signals. Then, the impulse response is subjected to Fourier transform to produce complex data consisting of real parts and imaginary parts with respect to an axis of frequency. The real parts and imaginary parts of the complex data are respectively subjected to smoothing processes to produce average data, which are combined together to form smoothed complex data. The smoothed complex data are subjected to inverse Fourier transform to produce anechoic-chamber-equivalent impulse response, which is a simulated impulse response of an anechoic chamber substantially corresponding to the impulse response actually measured in the echo chamber.

Impulse response measuring method

A howling canceling apparatus is provided in a sound system containing a microphone, a loudspeaker and an amplifier for canceling howling which may occur by feedback of sound from the loudspeaker to the microphone. In the howling canceling apparatus, a measuring section measures an impulse response of the sound system to determine a time length of a decay portion of the impulse response. A detecting section detects an occurrence of the howling when the determined time length is longer than a predetermined reference time length, and further analyzes a frequency spectrum of the decay portion of the impulse response to determine a frequency point at which the howling occurs. An attenuating section attenuates a frequency component of the sound around the determined frequency point so as to cancel the howling.

Apparatus detecting howling by decay profile of impulse response in sound system

An input device sequentially receives a first packet and a second packet that immediately follows the first packet, each of the first and second packets comprising a system time and audio data. A difference determining device determines a difference between the system time of the first packet and the system time of the second packet. A clock generating device generates a clock signal based on the system time of the first packet when the input device receives the first packet, generates a clock signal based on the system time of the second packet when the input device receives the second packet, and thereafter generates a clock signal based on a value obtained by adding the system time of the second packet and the difference between the system time of the first packet and the system time of the second packet.

Clock generating system generating clock based on value obtained by adding second time information and difference between first time information and second time information

The audio signal processor has a harmonics modifier for processing an input audio signal to produce an output audio signal. The harmonics modifier is comprised of translating means for sequentially translating the input audio signal into an address signal according to a sampled amplitude of the input audio signal. Memory means is provided for storing an input/output conversion table containing amplitude values in addressable manner. Conversion means operates for accessing the memory means in response to the address signal to effect input/output conversion to read out a sequence of the amplitude values which form the output audio signal containing desired harmonic components according to results of the input/output conversion.

Digital audio signal processor with harmonics modification

An acoustic characteristic correction device includes a section for setting a desired characteristic of a response characteristic in a reproduction system including a sound field, a section for outputting information of a measured characteristic of the response characteristic, a section for computing a correction characteristic for realizing the desired characteristic on the basis of the desired characteristic and the measured characteristic, and a section for imparting the computed correction characteristic to a sound signal to be reproduced. The device may further includes a display section for displaying the set desired characteristic, a section for controlling the level or frequency of the computed correction characteristic, a section for imparting a compensation characteristic to the correction characteristic. Results of measurement at plural points for plural measuring times may be stored and an average value of the results of measurement may be used as a measuring signal. In measuring a response characteristic by using a TSP signal, a convolution operator may be used commonly for time compression by an inverse filter characteristic and imparting of a correction characteristic.

Acoustic characteristic correction device

A moving magnetic pickup cartridge including: a vibratory system having; a stylus arm in a cantilever fashion, a stylus being provided at a free end of the stylus arm, and a permanent magnet being provided at a fixed end of the stylus arm, the magnet being magnetized in a direction of an axis of the stylus arm; a magnetoelectric converting system including; a stationary core having first, second and third yoke members magnetically coupled at their one pole ends to each other, the first and second yoke members having their other pole ends face respective lateral peripheral sides of the permanent magnet while the third yoke member has its other pole end facing an upper periphery of the magnet; and a coil system which includes at least two sets of coils, each set of which is wound around the first, second and third yoke members, one set of coils producing a sum of a horizontal signal and a vertical signal corresponding respectively to a horizontal component and a vertical component of the magnet vibration, the other set of coils producing a difference between the horizontal and vertical signals.

Pickup cartridge of moving magnet type

A moving coil type pickup cartridge comprises at least two movement-electromagnetism conversion systems functioning in push-pull mode, each system being arranged by a coil supported on a plate and inserted in an air gap between two opposing magnet blocks each constituted by side-to-side two magnets so as to provide opposite magnetic poles facing each other with the air gap intervening therebetween. A linear movement of the coil is allowed in the air gap in the directions of cutting the magnetic fluxes in the magnetic fields produced between the opposing magnet blocks. This arrangement provides a high density of magnetic fluxes and a high output voltage and improves the quality of signals reproduced. This effect is promoted further by yoke plates of a material of high magnetic permeability arranged to straddle the open magnet poles of the side-to-side magnets, thereby inhibiting leak of magnetic fluxes from these open poles. Vertical compliance of the vibration system can be made small during tracing a warped record disk by the use of an asymmetrically shaped armature. Good contact of damper to armature can be secured by fitting the armature into the damper. This cartridge may be made integral with head shell.

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Hamamatsu, Japan

Tsugio Ito