A half duplex amplifier for a cable network.

A method for controlling gain of a line amplifier on a cable, the method comprising selecting an unused carrier frequency; transmitting a pulsed pilot signal on the unused carrier frequency into the cable; determining a pilot signal output strength by measuring signal strength of the pilot signal after amplification by the line amplifier; comparing the pilot signal output strength with a target signal strength to determine a difference; and adjusting the gain of the line amplifier corresponding to the difference.

Methods, systems, and computer program products that infer and correct automatic gain compensation (AGC) values over time are described. A device emits a series of inaudible reference audio signals during recording. The reference audio signals have a constant amplitude. A microphone of the device records the reference audio signals while recording audio content. The device may apply AGC during the recording. An AGC inference module receives the recorded signals and extracts a representation of the reference audio signals, which have been subject to the AGC. The AGC inference module determines variations in levels of the extracted representation of the reference audio signals over time. Based on the variations, the AGC inference module infers the AGC applied to the recording over time. The AGC inference module can then provide the AGC for reading, or undo effects of the AGC applied to the audio content.

According to aspects of the present disclosures, an acoustic signal processing device includes a sound pressure measurement section configured to measure a sound pressure of a sound output from a speaker, a recording level obtaining section configured to obtain a recording level of an audio signal which is a signal representing the sound, and a gain increasing section configured to increase a gain to the audio signal when the sound pressure measured by the sound pressure measurement section is equal to or larger than a first threshold and the recording level obtained by the recording level obtaining section is less than a second threshold.

A system and method for digital processing including a gain element to process an input audio signal, a high pass filter to then filter the signal and create a high pass signal, a first filter module to filter the high pass signal and create a first filtered signal and a splitter to split the high pass signal into two high pass signals. The first filter module filters one high pass signals before a first compressor modulates the signal or a high pass signal to create a modulated signal. A second filter module filters the modulated signal to create a second filtered signal that is processed by a first processing module including a band splitter that splits the signal into low and high band signals that are then modulated by compressors. A second processing module processes the modulated low and high band signals to create an output signal.

A method of regulating power supply to a speaker and a system for regulating power supply to a speaker comprising a generating of a low frequency signal output to the speaker, sensing a current and a voltage of the speaker after the low frequency signal is output to the speaker, measuring an impedance of the speaker based on the current and voltage, determining a temperature of the speaker and comparing with a threshold value, and lowering a power supply to the speaker where the temperature is above the threshold value.

A system and method for digital processing including a gain element to process an input audio signal, a high pass filter to then filter the signal and create a high pass signal, a first filter module to filter the high pass signal and create a first filtered signal and a splitter to split the high pass signal into two high pass signals. The first filter module filters one high pass signals before a first compressor modulates the signal or a high pass signal to create a modulated signal. A second filter module filters the modulated signal to create a second filtered signal that is processed by a first processing module including a band splitter that splits the signal into low and high band signals that are then modulated by compressors. A second processing module processes the modulated low and high band signals to create an output signal.

An audio power output circuit provides a pair of output signals to an audio output transducer that has two different voice coils. Using a measured or predicted position of the voice coil assembly with respect to the transducer's magnetic field, a processing circuit generates the pair of signals such that a first relationship between a first one of the pair of output signals and an audio input signal and a second relationship between a second one of the pair of the output signals vary with the position of the voice coil. Offset in the Dynamic Mean Position (DMP) can be compensated for without adding low frequency or direct current components that compromise the dynamic range of the transducer. The efficiency, acoustic output power and/or linearity of the acoustic output of the transducer may be optimized by tailoring the first and second relationship to a particular target performance.

A method of regulating power supply to a speaker and a system for regulating power supply to a speaker comprising a generating of a low frequency signal output to the speaker, sensing a current and a voltage of the speaker after the low frequency signal is output to the speaker, measuring an impedance of the speaker based on the current and voltage, determining a temperature of the speaker and comparing with a threshold value, and lowering a power supply to the speaker where the temperature is above the threshold value.

Driver circuitry is disclosed for driving an electroacoustic transducer to provide an output comprising both ultrasonic and audio signal components. The driver circuitry comprises an adjustment module configured to reduce the level of said ultrasonic component signal in response to an increase in an operational variable indicative of a level of said audio signal component, while also increasing the pulse duration, duty cycle, repetition frequency or frequency span or bandwidth of the ultrasonic component.