Abstract: An audio noise mitigation approach. For one aspect, a first voltage associated with a first power management state is provided. A signal responsive to an indication associated with at least a first type of periodic exit event is received and responsive to the signal, a transition to a second voltage associated with a second state is initiated, a rate of the transition to the second voltage being slower than a similar voltage transition initiated in response to a non-periodic exit event.

Abstract: Circuit architecture is disclosed that includes one or more half bridges, the one or more half bridges including signal processing circuitry including first and second inputs and one or more outputs. The circuit architecture also includes a driver stage coupled to the one or more outputs of the signal processing circuitry and configured to create at least one output, one of the at least one outputs suitable to couple to a load. The circuit architecture further includes a first feedback loop coupling the at least one output of the driver stage to a first input of the signal processing stage, and includes a second feedback loop coupling the at least one output of the driver stage to a second input of the signal processing stage, where signals on the first and second feedback loops have inverted polarity. Methods and computer-readable media are also disclosed.

Abstract: A system that allows the teammates of an individual (such as a quarterback on a football team) to hear signals being called by that individual during the course of a sports competition, despite noise generated by an audience. The system includes a microphone positioned within the helmet of the signal caller connected to an audio amplification device, either positioned in the helmet or in some other part of the clothing or equipment worn by the signal caller. The amplified signal is then directed to one or more loudspeakers, again positioned either on the helmet of the signal caller or on the clothing or equipment worn by the signal caller. The loudspeakers are directed to the signal caller's teammates, positioned typically along a line of scrimmage. The system may be time-limited in operation in that the signal caller must specifically activate the system which thereafter remains activated only for a pre-set period of time before automatically shutting off.

Abstract: A circuit for processing sound signals includes an input amplifier for amplifying an input signal, wherein the amplified input signal is supplied to an output amplifier unchanged via a primary path configured as a bypass line and processed via one or several secondary paths configured as a circuit for processing the amplified input signal for amplifying and outputting the processed signal, wherein respective signal portions of the amplified input signal, which are supplied to the output amplifier via the primary path and the secondary path(s), can each be adjusted with an adjusting device, and wherein the secondary path includes a corresponding equalizing filter for filtering a corresponding frequency range with a dynamic circuit for optionally dynamically changing frequency, amplitude and phase depending on the signal and concurrent with a static control.

Abstract: A digital audio signal amplifier includes: a digital signal amplifying module having a digital audio signal plug connected with a digital audio signal outlet of a main board to receive digital audio signals, the digital signal amplifying module processing the digital audio signals to generate high power analog audio signals; and an analog signal output interface coupled to the digital signal amplifying module and transferring the high power analog audio signals to a set of speaker.

Abstract: A sound generating device for transforming an object into a loudspeaker is includes an exciter module adapted for receiving audio signals stored on a portable micro-memory card or the like and a mounting device connected to the exciter module for removably connecting the exciter module to an object such that the object is transformed into a loudspeaker when the exciter module is energized by the audio signals.

Abstract: Ground skimming output stages that are designed to drive wideband signals with the ability to provide a high quality output signal all the way to the low supply rail are provided. In accordance with an embodiment of the present invention, the output stage of the present invention includes a translinear current controller, an output transistor and a current mirror. While not limited thereto, embodiments of the present invention only require a single positive power supply, consistent with the recent trend toward integrated circuits that only require a single low voltage power supply.

Abstract: An audio power amplifier IC which is capable of suppressing degradation in sound quality resulting from the frequency of a reference clock, and an audio system provided with the audio power amplifier IC are provided. The audio power amplifier IC includes a clock generation circuit generating an internal clock, a clock terminal for outputting the internal clock or receiving an external clock, a clock selection circuit selecting the internal clock or the external clock as a reference clock, a first audio signal input terminal for receiving a first audio signal, and a first digital power amplifier circuit performing pulse modulation on the first audio signal based on the reference clock to output a pulse synchronized with the reference clock.

Abstract: A multimode audio amplifier comprises: a mode controller adapted to provide a control signal; and at least one multimode module, wherein each of the multimode modules has a plurality of operating modes, wherein the operating modes are selected in accordance with the control signal, wherein changing the operating modes results in a measurable change in at least one characteristic of the multimode audio amplifier; wherein the characteristics of the multimode audio amplifier consist of signal to noise ratio (SNR); total harmonic distortion and noise (THD+N); input to output delay; power consumption; and efficiency.

Abstract: A system comprising converter logic that introduces noise to a signal. The system also comprises amplifier logic that reduces a sound pressure associated with the noise by amplifying the signal prior to providing the signal to the converter logic and de-amplifying the signal after providing the signal to the converter logic.

Abstract: The speaker apparatus according to the invention is arranged in a manner that when the magnitude of an audio signal Sin increases temporarily and so a consumption power increases, a DC-DC converter reduces an output voltage Vout to thereby increase an output current Iout and further discharges a capacitor to thereby increase a current supplied to an amplifier. Thus, a power of 2.5 W or more supplied from a USB connection terminal can be temporarily supplied to the amplifier.

Abstract: A modular speaker system includes a base assembly having a longitudinally extending, central support member and a support leg extending therefrom in a manner supporting the central support member in a generally upright configuration. The central support member includes a first end and a second end. A first woofer is secured to the base assembly, and a base assembly amplifier is mounted within the central support member and connected to the first woofer. An auxiliary speaker assembly includes a longitudinally extending, auxiliary support member having a first end a second end, the first end being shaped and dimensioned for selective engagement with the second end of the central support member. A first driver is secured to the auxiliary speaker assembly and an amplifier is mounted within the auxiliary support member and is connected to the first driver.

Abstract: A device for producing sound amplification having a control module operably associated with a digital sound device, and an amplifier connected to and supporting the digital sound device. The control module provides at least one input signal to the digital sound device, and the digital sound device receives an input signal from the control module, causing the digital sound device to produce a vibration, and causing the amplifier to increase the magnitude of the vibration.

Abstract: In an active loudspeaker, a bridge rectifier generates an unregulated DC voltage from the AC mains power supply voltage. A self-oscillating pulse modulator generates a pulse-modulated switch signal that is controlling a power switch stage which is switching the unregulated DC voltage. The power-switched signal is low-pass filtered and driving a high-impedance speaker element. The amplifier is compensating fluctuations and noise in the unregulated DC voltage by feeding a reference signal back to the pulse modulator which is derived by voltage-dividing the power-switched signal. The audio volume is regulated by adjusting the voltage divider ratio of the feedback signal. The loudspeaker provides galvanic voltage isolation of the speaker inputs through an audio input stage to comply with safety regulations. This invention eliminates the regulated switched-mode power supply in active loudspeaker applications and thereby reduces cost and weight.

Abstract: A circuit, which is enabling the superpositioning of different audio signals such as voice, music or ringer signals in a audio output device is achieved. The individual superpositioning can be activated and performed by a combination of resistors and switches without the need of an additional mixing amplifier as in prior art. One common output stage is used for all the signals activated and superpositioned. The adjustment of the amplitude of the output signal, which can be used for the volume adjustment of a loudspeaker, is provided by a precise amplitude setting via the gain control stages of an inverting voltage amplifier through a current-voltage conversion. Said current-voltage conversion is performed by a string of resistors activated by a string of correspondent switches. This circuit reduces the power consumption, the chip area required and the offset and improves the power supply rejection rate (PSSR).

Abstract: This application relates to an outdoor music and sound system. More particularly, this system incorporates unique weatherproof wing nut cable connectors used in connecting a plurality of weatherproof speakers on a single electrical line to a remote sound system that may be employed in a variety of landscape areas. By using 8 ohm, at 20 to 50 watt resistor units, or a 1.5 to 2 ohm receiver amplifier, to control the output, a single cable can be used to connect to a plurality of speakers. Two or more cables may be connected to the electronics unit. This inexpensive system can easily be sold at discount hardware stores in conjunction with the wide variety of inexpensive outdoor lighting systems now available.

Abstract: Disclosed is an audio equipment, comprising: an audio output amplifier and a speaker, with a sound output from the speaker based on an audio signal that is input in the audio output amplifier, and with a high signal output as an error signal to protect the audio output amplifier when an abnormal operation occurs. The audio equipment further comprising a rectifier circuit to stabilize the error signal.

Abstract: An instrument amplifier includes an amplifier circuit for amplifying a sound signal input from an electric guitar. A main speaker emits sound according to the sound signal being amplified. A CD player plays back an audio signal from an audio CD. Side speakers for playback emits audio sound according to the audio signal being played back. A speaker box contains the main speaker and the side speakers in one space. In one embodiment, the speaker box includes a rear panel for closing a space behind the main speaker and the side speakers. Furthermore, an output mode key is settable in a first mode by external operation, the first mode being for controlling the playback speaker to emit sound according to the sound signal. The side speakers are disposed beside one another, for stereo sound emission of the audio sound.

Abstract: An audio amplifier comprises: a first stage and a second stage amplifiers each respectively providing an output to a speaker; a first resistor electrically connected in parallel with the first stage amplifier; a second resistor electrically connected in series with an input of the first stage amplifier; a third resistor electrically connected in parallel with the second stage amplifier; a fourth resistor electrically connected in series with an input of the second stage amplifier, and also electrically connected in series with an output of the first stage amplifier; and a variable resistor electrically connected in parallel with the first resistor, the variable resistor and the first resistor forming a variable resistance parallel circuit.

Abstract: The present invention is an apparatus and a concomitant method for boosting the audio signal generated by at least one notification appliance in a supervised emergency voice evacuation system.

Abstract: A microphone amplifier arrangement comprises at least one microphone input connected to a dual output microphone pre-amplifier having an input resistance comprising a first resistance and a second resistance in a first voltage-to-voltage mode of operation, and only the second resistance in a second current-to-voltage mode of operation. A first output is operably coupled to a first feedback path comprising a V2V feedback resistor; and a second output is operably coupled to a second feedback path comprising an I2V feedback resistor. In this manner, the microphone amplifier arrangement is arranged to support both a V2V microphone amplifier and a low-noise I2V microphone amplifier.

Abstract: An audio output circuit including an input-signal generation block generating an input signal obtained by integrating a cyclic waveform and inputting the input signal to an audio amplifier at a transition from a normal operation to a power down state or at a return from the power down state to the normal operation, wherein an amplifier output terminal of the audio amplifier and an audio output unit are coupled via a capacitor.

Abstract: In a sound receiver, a sound wave is directly received by microphones at a predetermined phase difference. The microphones are arranged in opening cavities of a casing, at positions that are different from the volume center points of the opening cavities. The microphones are supported by supporting springs in a state of not closely contacting inner peripheral walls. The sound wave received by the microphones is input to a signal processing unit and after a signal component in a predetermined low frequency band is removed by a filter, the resulting sound wave is amplified by an amplifier and is made in phase by a phase shifter and output.

Abstract: A semiconductor integrated circuit includes a capacitor element which defines a prescribed decay time constant with one or more resistors, an MOS transistor connected to the capacitor element via its gate, and a constant current generating element which generates a constant current. The capacitor element is charged with the constant current so as to create a linearly changing voltage. The linearly changing voltage is applied to the gate so that the MOS transistor can accordingly output a smoothly changing current.

Abstract: An output filter for a switching audio amplifier includes a magnetic core having a gapped central leg and a first and a second outer leg. The central leg and the first outer leg form a first independent magnetic path and the central leg and the second outer leg form a second independent magnetic path. The first and the second outer leg together form a joint magnetic path. A first coil having a first plurality of turns is wound around the first outer leg. A first load current applied to the first coil generates a first magnetic flux in a first direction through the joint magnetic path. A second coil having second plurality of turns is wound around the second outer leg. A second load current applied to the second coil generates a second magnetic flux in a second direction opposite to the first direction through the joint magnetic path.

Abstract: A guitar amplifier having at least one channel, each channel having a differential amplifier with first and second amplifying members, each amplifying member having a control element, an electron emitting element and an electron collecting element, the electron emitting elements of the amplifying members commonly coupled and an output amplifier coupled to the differential amplifier and having an output terminal selectively coupled to the control element of the second amplifying member of the differential amplifier as a feedback path. An input terminal coupled to the control element of the first amplifying member and a user-adjustable presence control circuit selectively coupled between the control element of the first amplifying member and ground to increase the perceived brightness, when selected. The presence control circuit includes a high pass filter disposed between the input terminal and ground to filter a selected high frequency portion of the signal received at the input terminal.

Abstract: A vocal monitor comprises a “J”-shaped base portion. The base portion comprises a bottom surface having a mouth region and an ear region. First and second sides extend in a first direction from the bottom surface. First and second ends extend in the first direction from the bottom surface and connect to the first and second sides. The bottom surface, the first and second sides and the first and second ends define a sound reflecting chamber. A cavity is defined in the bottom surface adjacent to the mouth region. The cavity includes an opening for removably receiving one of a plug and a mouthpiece portion of a microphone.

Abstract: A method of, and apparatus for, limiting inputs to and outputs from a computer sound card forms a feedback connection between the input and output of the sound card amplifier. The voltage of the feedback connection is increased from minimum voltage until an over-saturation condition occurs. This finds the “output voltage limit.” Thereafter, the output voltage of the amplifier is restricted to the output voltage limit. The feedback connection is then terminated and the voltage of the signal being supplied to the amplifier is increased from minimum voltage until the over-saturation condition again occurs. This finds the “input voltage limit.” Thereafter, the input supplied to the amplifier is restricted to the input voltage limit.

Abstract: Various embodiments of the invention are directed toward a multi-zone audio distribution, amplification, and control system for use with structured wiring systems. Various embodiments of the invention allow audio signals received from multiple input sources to be selectively distributed to multiple zones in a home or building over a structured wiring system.

Abstract: An electronic audio amplifier circuit, operable in two modes and a battery powered portable audio apparatus incorporating the circuit; and associated apparatuses and methods. When in the first mode the audio apparatus is designed for the direct driving of headphones or a speaker. When in the second mode the audio apparatus is designed to drive a line input of an external amplifying apparatus with a signal that having a higher voltage amplitude for a given signal content than when driving headphone or a speaker. The circuit has common output stage circuitry for use in both modes, and a dual mode power supply circuit, ideally a charge pump circuit, for supplying the output stage in the first mode with a lower supply voltage than in the second mode.

Abstract: A computerized wagering game system has a gaming module comprising a processor and gaming code which is operable when executed on the processor to conduct a wagering game on which monetary value can be wagered, and an audio module comprising a digital audio amplifier, the audio module operable to receive digital audio signals and to amplify them to produce an amplified digital audio signal. In some embodiments, the digital amplifier produces a pulse width modulated amplified digital audio signal, which is in further embodiments also pulse frequency modulated.

Abstract: An amplifier that receives an input signal and outputs an amplified output signal includes an integration stage, a comparison stage, and a full bridge circuit. The integration stage is be used for receiving a constant common mode voltage, for receiving a first signal representing the input signal of the amplifier, and for generating a ramp signal. The comparison stage coupled to the integration stage is used for generating a pulse width modulation signal according to the ramp signal and according to a hysteretic signal. The full bridge circuit coupled to the comparison stage is used for receiving a power supply and the pulse width modulation signal, and for generating the output of the amplifier.

Abstract: A method and apparatus for controlling a selectable voltage audio power output stage provides a mechanism for raising the selected power amplifier output voltage in time for the arrival of signal peaks to avoid clipping. Signal peaks may either be delayed by delaying an increase in volume control level or enabling signal compression for a predetermined time period, so that sufficient time is provided for the amplifier power supply to stabilize at a higher operating voltage when an increase of power supply voltage is selected. Alternatively, a signal level may be determined at an upstream source, such as a decoder or filter that provides information in sufficient advance of the arrival of the peaks, and used to control the power supply selection, so that the higher power supply voltage level is selected in advance of arrival of the signal peaks that would otherwise cause clipping at the power amplifier output.

Abstract: An audio system and method of generating an amplified audio signal comprises a class-D audio amplifier; and a battery directly connected to the class-D audio amplifier, wherein the direct connection between the battery and the class-D audio amplifier achieves a power efficiency greater than approximately 90%. The audio system may further comprise an analog-to-digital converter (ADC) adapted to digitize an output voltage of the battery and digital signal processing to maintain constant audio volume regardless of the battery voltage drift.

Abstract: A M-bridge class-D audio amplifier for portable applications and a method of driving a three-wire audio output device comprises a stereo signal source producing a first and second input stereo digital signal; circuitry adapted to receive the first and second input stereo digital signals and produce three stereo signals comprising a first, second, and third digital signal, wherein the three stereo signals generate pulse-width modulation (PWM) waves comprising a first, second, and third digital signal PWM wave; exactly three pairs of MOSFETs driven by the first, second, and third digital signal PWM waves; and a three-wire speaker system comprising a first wire driven by the first digital signal PWM wave; a second wire driven by the second digital signal PWM wave; and a common wire driven by the third digital signal PWM wave.

Abstract: A Harmonic Generator for audio applications and a Pre-Amplifier circuit are combined to form a Harmonic Generator and Pre-Amplifier circuit. The Harmonic Generator is formed from a Buffer Circuit responsive to an input program signal for buffering the input program signal and for providing a buffered input program signal. A Modulator Circuit is coupled to receive the buffered input program signal and generates harmonics in response to changes in amplitude of the program input signal to provide a modulated input program signal. A Summing Circuit adds the buffered input program signal and the modulated input program signal to provide a composite modulated input program signal. The Pre-Amplifier is coupled to receive the composite modulated input programing signal and process the signal in three audio frequency bands to provide a compensated output signal that includes harmonics generated by the modulator.

Abstract: An audio amplifier system. The power supply includes a plurality of power lines. The mainboard includes a first voltage input connector coupled to one of the power lines receiving a first power supply, and an audio output signal connector outputting a first audio output signal. The audio amplifier module located on a chassis includes a second voltage input connector coupled to the others receiving a second power supply, an audio input signal connector coupled to the audio output signal connector via a cable receiving the first audio output signal, and an amplifier circuit amplifying the first audio output signal into a second audio output signal.

Abstract: An audio amplifier unit for a bicycle audio system includes audio amplifier circuitry and a rechargeable battery powering the audio amplifier circuitry which are housed in a weather resistant housing sized to be received and retained within a bicycle water bottle holder. Electrical connections are provided for connecting the amplifier circuitry to a personal audio device and at least one external speaker.

Abstract: Embodiments of the present invention include switching amplifier circuits and methods. In one embodiment, the present invention includes an audio amplification method comprising modulating an audio input signal to produce a first modulated signal and a second modulated signal, amplifying the first modulated signal to generate an amplified first modulated signal at a first output terminal of an amplifier, and amplifying the second modulated signal to generate an amplified second modulated signal at a second output terminal of the amplifier, wherein the first output terminal of the amplifier is constant when the second output terminal of the amplifier is switching, and wherein the second output terminal of the amplifier is constant when the first output terminal of the amplifier is switching.

Abstract: A system and method for modulating the sound pressure that is output from an audio transducer is disclosed. In one embodiment, the method includes receiving an audio signal and placing the audio signal across a voice coil of the transducer. In addition, a voltage is applied across a field coil of the transducer, the field coil being separate from the voice coil. And the voltage that is applied across the field coil is adjusted so as to modulate the sound pressure output from the audio transducer.

Abstract: In the present invention, in parallel with a resistor which determines an amplification rate being fed back from an output to an input of an output stage OP amp in an audio amplifier circuit, providing a first diodes connected bi-directionally together with a first switch circuit, the output voltage of the output stage OP amp is limited to a voltage, when the first diodes are turned ON. The limit voltage of the first diodes corresponds to a speaker having a low withstand voltage. Accordingly, through ON/OFF of the first switch circuit, a power output from the output stage OP amp can be selected depending on the withstand voltage of a speaker to be connected.

Abstract: An audio amplifier includes a plurality of sub-audio amplifier sets, a clock source, and a speaker. When the audio amplifier is under an audio amplify mode, the plurality of sub-audio amplifier sets is operated under a synchronic operating frequency with a same clock signal generated by the clock source. When the audio amplifier is under a self-oscillation mode, the clock signal is isolated from being input to the plurality of sub-audio amplifier sets. A higher distortion is prevented by repeatedly charging and discharging an oscillating capacitor of a sub-audio amplifier in a sub-audio amplifier set.

Abstract: An audio player capable of allowing multiple persons to listen to different multimedia files simultaneously is provided. The audio player includes a processing unit and a plurality of output channels. Each of the output channels is configured for outputting multimedia files. Each of the output channels includes a codec, an amplifier, and an audio output port. The amplifier is connected to the codec and the audio output port. The processing unit is connected with the output channels. The processing unit is configured for establishing a plurality of processes and for controlling performance of the processes according to time division multiplexing (TDM) technology. Wherein, each of the processes is configured for playing multimedia files and is assigned with one of the output channels for outputting the multimedia files.

Abstract: A method of amplification includes amplifying an input signal with a predetermined or user adjustable maximum gain to produce a second signal and compressing the dynamic range of the second signal with an automatic gain control to produce an output signal. The compression ratio of the automatic gain control is greater than one for output signals below a predetermined threshold output signal level and is essentially one for output signals above the predetermined threshold output signal level. The compression ratio may be predetermined or the method may include determining the compression ratio of the automatic gain control. The compression ratio may be determined according to the amplitude of the output signal or according to an input-output curve. The input-output curve my be predetermined and may be selected according to the auditory needs of a listener. Preferably the input-output curve is determined according to the predetermined or user adjustable maximum gain.

Abstract: An audio control method and audio processing system utilize an ADC to sample an analog audio input signal and convert it to a digital audio signal. A control module determines input signal level from the digital audio signal. Based on different input signal levels, output gain range of the amplifier can be set. In this way, the present invention can prevent speakers being burned out or volume being too low.

Abstract: A mobile terminal has an audio device to adjust the gain of an audio amplifier depending on whether the terminal is in an open or a closed position. The audio amplifier provides an audio signal to a speaker, and the volume of the audio signal is proportional to the gain of the audio amplifier. One of a plurality of gain control circuits is selected according to the position of the terminal and is provided to the audio amplifier to adjust the gain. Therefore, the gain of the audio amplifier may be greater when the terminal is in the closed position than in the open position. Alternatively, one of the gain control circuits may be selected according to a measure of the ambient noise surrounding the terminal, or may be manually selected by a user.

Abstract: A mobile communication terminal with three-dimensional surround-sound effect system has a data processing section for coding and modulating a transmitting signal or demodulating and decoding a receiving signal, and an audio processing section for reproducing an audio signal input from the data processing section or transferring the audio signal input from a microphone to the data processing section. The audio signal has a first audio signal for one speaker and a second audio signal for the other speaker. A first audio path has a first amplifier for amplifying the first audio signal and a first delay for delaying in phase the first audio signal, and a second audio path has a second amplifier for amplifying the second audio signal and a second delay for delaying in phase the second audio signal. A voltage measurer measures the voltage of the first and second audio signals. A comparator compares the first and the second audio signals.

Abstract: An energy-efficient consumer device audio power output stage provides improved battery life and reduced power dissipation. A power supply having a selectable operating mode supplies the power supply rails to the power amplified output stage. The operating mode is controlled in conformity with the audio signal level, which may be determined from a volume control setting of the device and/or from a signal level detector that determines the amplitude of the signal being amplified. The power supply may be a charge pump in which the operating mode uses a capacitive divider to provide for selection of a power supply output voltage that is a rational fraction of the power supply output voltage in a full-voltage operating mode.

Abstract: A digital audio driver having a floating PWM input and for controlling a stage of high voltage, high speed high- and low-side MOSFETs series connected at a node. The driver includes a floating input interface circuit having a protection circuit to provide secure protection sequence against over-current conditions; and high and low side circuits for driving the high- and low-side MOSFETs, each high and low side circuit including a bi-directional current sensing circuit which requires no external shunt resistors that enables capture of over-current conditions at either positive or negative load current direction. The RDS(ON) of the high- and low-side MOSFETs is used as current sensing resistors, once the RDS(ON) exceeds a pre-determined threshold, an over current output signal is fed to the protection block to shutdown the MOSFET to protect the devices.

Abstract: A loudspeaker is provided for receiving an incoming electrical signal and transmitting an acoustical signal. The loudspeaker may include a power amplifier that has an input and an output, where the input receives the incoming electrical signal. The loudspeaker may also include two or more passive filters, such as low-pass, band-pass, and/or high-pass filters, which are coupled to the output of the power amplifier. The passive filters may also be coupled to one or more speaker drivers. The arrangement of passive filters and speaker drivers may have a single input that has a combined input impedance. The output of the amplifier may have an output impedance. The output impedance may be between about 25% and about 400% of the combined input impedance. The power amplifier may include a current-feedback amplifier that is configured to maintain the desired output impedance.