Abstract: High and low frequency components Cn1, Cn2 are generated by causing a center channel audio signal Cn to pass through a high-pass filter HPF and a low-pass filter LPF, and the high frequency component Cn1 is supplied to the center channel loudspeaker SPC. Also, two low frequency components Cn2L, Cn2R, which have a different phase mutually, are generated by causing the low frequency component Cn2 to pass through phase shifters 2, 3. An synthesized audio signal SL is generated by synthesizing the low frequency component Cn2L and the front-left channel audio signal FL, and then supplied to the front-left channel loudspeaker SPL. An synthesized audio signal SR is generated by synthesizing the low frequency component Cn2R and the front-right channel audio signal FR, and is supplied to the front-right channel loudspeaker SPR.

Abstract: Provides a one-terminal effector having an input terminal and an output terminal structured as one terminal by providing a circuit that makes input and output of the effector common. The one-terminal effector can avoid complex cable wiring, and can prevent degradation of sound quality. The one-terminal effector includes one input/output terminal, and an effector circuit that executes a predetermined processing on an analog audio signal that is input from the input/output terminal, and outputs the processed analog audio signal from the input/output terminal. The one-terminal effector further includes an input/output signal conversion circuit that converts the input signal and the output signal into mutually different signal forms of voltage signals or current signals.

Abstract: Eyewear is disclosed for use in sports and the like which allows the wearer to adjust the flow of air across the inside surface of the lens without having to remove the eyewear. The eyewear includes a frame shaped to fit a wearer's face, one or two lenses mounted in the frame, and a temple bracket mounted on each side of the frame. Each temple bracket has a front surface substantially contiguous with the front surface of the frame and containing an inlet opening. An inner surface of each temple bracket contains an outlet opening and a passageway connecting the inlet opening and outlet opening. A block is positioned for sliding movement in the passageway and is connected to a button mounted for sliding movement on the outer surface of each temple bracket.

Abstract: A pickup amplifier system for a public address system including an amplifier, an amplifier box and a speaker simulator microphone wired between amplifier and amplifier box.The amplifier system is characterized by the following features:the speaker simulator is arranged in the area of the amplifier box, close by or on its front face; and,an acoustic pickup is arranged directly before on the front face of the amplifier box.

Abstract: A system and method is provided for performing sound synthesis with delay-based special effects which may be algorithmically implemented using one or more time-delay elements The system implements the time-delay elements by using system memory to store time-delay data. The system and method described herein utilizes the benefits of a high bandwidth I/O bus while mitigating the disadvantages introduced by having to arbitrate for a shared system bus. By using system memory for storing time-delay data, a more cost effective PC audio system can be produced.

Abstract: An audio tremolo producing system uses a rotating horn as a tremolo producing device for mid and high frequency audio signals, and an electronic tremolo producing device capable of both phase and amplitude modulation for low frequency signals.

Abstract: A digital sound generator with tremolo and vibrato sound effects is provided, which comprises: a source memory for storing different types of wave-tables; a first adder for adding a constant frequency and a step-varied frequency waveform to produce a tremulous frequency waveform; a register for storing a frequency address parameter from a central processing unit; an address generator for generating a frequency address in response to the frequency address parameter to said source memory to determine the type of signal waveform being outputted, so that said source memory produces a tremolo by playing the tremulous frequency waveform in the determined signal waveform; an amplitude generator for generating the amplitude of a normal sound; a second adder for adding the amplitude from the amplitude generator and an amplitude-variant signal from the source memory to produce a vibrato; and a synthesizer for synthesizing the tremolo and the vibrato to produce a sound with a special sound effect.

Abstract: An electronic music system adapted to generate tone waves of different pitch, amplitude and duration which, when reproduced, create musical tones whose expressive qualities emulate the expressive quality of natural tones producible by acoustic instruments or the human voice. The system includes a tone wave generator, the carrier of which is frequency modulated by an asymmetrical wave whose major component is a sinusoidal wave and whose minor component superimposed on the sinusoidal wave is the second harmonic of that wave. The frequency of the sinusoidal wave is such that as the carrier is frequency-modulated, its frequency is periodically varied above and below its normal value so that the resultant tone exhibits a vibrato effect. And the carrier is at the same time amplitude modulated so that it is periodically varied in amplitude to impart to the resultant tone a tremolo effect whereby the tone yielded by the system emulates a natural tone.

Abstract: A speaker simulator receives a high power musical signal from a power amplifier, and a reduced power signal is extracted by a pad circuit and directed to a high-pass filter and a fan circuit which drives a cooling fan. The output of the high-pass filter is directed to a servo amplifier and a series of notch filters, prior to output from the speaker simulator. The angular momentum of the blades of the cooling fan provides an history-dependent impedance, i.e., an impedance dependent on the past values of the signal driving the fan. The history-dependent impedance produces an aesthetically pleasing distortion of the speaker simulator output.

Abstract: A multi-stage solid state amplifier emulates the distortion associated with grid current flow in a multi-stage tube amplifier by means of a clipping device in the circuit between each series connected stage. In a particular embodiment, each stage includes a field effect transistor (FET) and the clipping device is a diode.

Abstract: A method is disclosed of modification of parameters of audio signals by dividing a digital signal converted from an original analog signal into sound frames, modifying a pitch and a playing rate of the digital signal within a frame and subsequent successive splicing a last modified frame with a first non-modified frame and calculating a differential mean absolute error to define the best splicing point in terms of producing minimal or no audible noise such that various sections of sound signals can be spliced together to achieve pitch and playing rate modification. An apparatus is also disclosed for implementing the method, the apparatus comprising input and output amplifiers, a low pass filter at the input and a low pass filter at the output, analog-to-digital and digital-to-analog converters, and a pitch shifting processor.

Abstract: A multi-stage solid state amplifier emulates the distortion associated with grid current flow in a multi-stage tube amplifier by means of a clipping device in the circuit between each series connected stage. In a particular embodiment, each stage includes a field effect transistor (FET) and the clipping device is a diode. In another embodiment, each stage includes a Darlington connected pair of transistors. An input diode and a multilevel biasing circuit emulates a tube circuit input.

Abstract: A digital audio signal processor for adding harmonic content to an input audio signal through a non-linear transfer function with discontinuities. The discontinuities are generated by bit shifting each input value by an amount dependent on the sign and magnitude of the input value. The amount by which the input value is shifted is roughly inversely related to the magnitude of the logarithm of the input value. The transfer function is fractal and so provides increased harmonic content for all signal amplitudes.

Abstract: The kinds of effects imparted to signals received from a keyboard or a microphone are stored beforehand in a first and a second effector. An effect (1) input selector and an effect (2) input selector set forms in which signals are fed to the respective effectors. A direct tone control switch, and effect (1) and (2) L/R switches set a form in which the signal with an imparted effect is output. The input forms of those signals, the kinds of effects and the output form of the signals with an imparted effect are displayed on a list display. The user operates a ten-key unit to select a desired input and output forms of the signals and the kinds of effects to be imparted to the signal while viewing the list display.

Abstract: A digital signal processor in which the control device transmits to and writes into the buffer memory the data necessary for multiplication or for generating addresses in the external memory, and then the data in the buffer memory is written into the internal memory during a single sampling period. This processing device contains an address comparator that compares the address set by the control device in the internal memory into which the data in the buffer memory is written, with the address in the internal memory controlled by the program, and then that produces control signals to write the data read from the buffer memory into the internal memory. The data read from the buffer memory is written into the internal memory, and is also used for multiplication or for generating addresses in the external memory.

Abstract: A preamplifier device employing electron tubes wherein the preamplifier has tremolo/vibrato circuits independent from reverb circuits allowing continuously variable control of either tremolo or vibrato effects simultaneous with continuously variable control of the reverb effect. A mixer control for controlling the level of reverb and a tone control is provided. Connections are provided for external switches used to disable any one of the above effects.

Abstract: A modulation effect adding apparatus in which when an input signal is written into a memory and read and output with a given delay time, the delay time is changed depending on an LFO waveform to thereby add a modulation effect to the input signal. The LFO waveform is obtained by passing through a low pass filter a waveform signal comprising multiple high harmonic components and changing in a positive- or negative-going direction at a particular period. By changing the characteristic of the low pass filter, various LFO waveforms are obtained. An offset value corresponding to the maximum peak value of the LFO waveform is added to the LFO waveform, and the resulting waveform is multiplied by an offset value having a predetermined magnification and inverting the waveform signal to thereby prevent a memory read address from disadvantageously exceeding a write address.

Abstract: A reverberation circuit comprises an amplifier, attenuation circuit, a feedback component, and a delay circuit. The amplifier, delay circuit, and feedback component form a feedback loop. The amplifier amplifies an input signal supplied to an input terminal and outputs an amplified signal to the delay circuit. The output of the delay circuit is fed through a feedback component back to the amplifier. The feedback component controllably varies the feedback amount of the delayed signal to the amplifier in accordance with the desired depth of reverberation. An attenuation circuit is placed in the feedback loop, or before or after the feedback loop. The attenuation circuit selectively attenuates the level of specific frequency component of a signal passing therethrough whose frequency may be different depending on the depth of reverberation or feedback amount.

Abstract: An input waveform signal is converted in an A/D converter into a digital signal to be written in a waveform memory under control of a tone generation control unit. The written digital signal is read out from the waveform memory with a designated delay time. The input waveform signal and the digital signal read out from the waveform memory are converted in a D/A converter into analog signals which are fed through VCFs and VCAs so as to be sounded. Further, in the above arrangement the timbre and tone volume controls are done independently for the individual waveform read/write channels through VCFs 12a to 12d and VCAs 13a to 13d. Thus, it is possible to obtain a further effected sound.

Abstract: A modulation effect device is implemented by utilizing a fact that a phase or frequency of an output signal from a digital filter can be varied by varying a filter-coefficient according to a lapse of time. A musical tone signal inputted into the digital filter is phase-or frequency-modulated in accordance with the variation of the filter coefficient, thereby imparting such modulation effect as vibrato, chorus or ensemble (symphonic chorus) to the musical tone signal.

Abstract: Sound projecting apparatus employs a microcomputer to pan a musical performance automatically, according to a preset program, and to display the instantaneous location of the apparent sound source by means of an array of lights.

Abstract: Tone signals from plural keyboard systems are supplied to an effect imparting circuit via a distribution circuit. The effect imparting circuit comprises plural effect imparting channels and the device can impart a tone effect independently to a tone signal provided to each of the effect imparting channels. The distribution circuit distributes tone signals from the respective keyboard systems to any one or more of the effect imparting channels. An effect selection device is provided for selecting tone effects for the respective keyboard systems and an effect assignment device is also provided for assigning the effects selected in the respective keyboard systems to any of the effect imparting channels according to the selection by this effect selection device. The distribution circuit delivers the respective tone signals to the proper effect imparting channels respectively as controlled by the effect selection and the effect assignment.

Abstract: A modulation effect device for use in an electronic musical instrument which utilizes, as a digital modulation circuit, a digital memory device for storing digitized musical tone signals. The digital memory device is accessed by modulation coefficient generating means which supplies a modulated address information to the digital memory device to read out from the memory device a musical tone signal modulated in accordance with the modulated address.

Abstract: A sound effect imparting device for an electronic musical instrument is capable of imparting a plurality of desired sound effect such as vibrato and reverberation effects to a digital musical tone generated from the electronic musical instrument. The device comprises a digital arithmetic operation unit constructed with a combination of adders, multipliers, delay circuits, etc., a control unit, a parameter memory and a read-out unit.By control data and parameter data which are respectively read out from the control unit and the parameter memory by means of the read-out unit, switching of the operation mode of the digital arithmetic operation unit is controlled in a time-sharing manner, whereby a plurality of sound effects are imparted to a musical tone through digital arithmetic operations.

Abstract: Electronic circuits are provided for producing an electronic timbre modulation for effecting celeste or vibrato similar in sonic results to the well-known Leslie rotating speaker system. Electronic signals corresponding to audio tones are generated and are modified by appropriate filters. Three controlling oscillators are locked in exactly 120.degree. phase relation to one another and act through three voltage controlled oscillators respectively to modulate three bucket brigade circuits through which said modified electronic signals are passed substantially in parallel. A roving band pass filter further modulates those of said electronic signals corresponding to flute tones to simulate other aspects of a Leslie speaker system.