A power control method for a charging system includes: detecting a power signal and an input voltage of the power signal; determining a charging protocol supported by the power signal; and determining whether to conduct a power switching circuit or not according to the input voltage of the power signal and the charging protocol supported by the power signal to provide power for an amplifier chip of the charging system.

Various aspects include audio amplifiers for driving at least one speaker. In some cases, the amplifier includes: a controller for amplifying at least one input signal to provide an amplified audio output signal, the controller configured to operate the amplifier in at least two modes, including: a first mode including a dedicated connection to the at least one speaker; and a second mode including a direct physical connection with an additional audio amplifier and the dedicated connection to the at least one speaker, where in the first mode and the second mode the amplifier is configured to provide the amplified audio output signal to drive the at least one speaker, and in the second mode the amplifier is configured to forward the at least one input signal to enable the additional audio amplifier to control audio output at an additional speaker.

Various aspects include audio amplifiers for driving at least one speaker. In some cases, the amplifier includes: a controller for amplifying at least one input signal to provide an amplified audio output signal, the controller configured to operate the amplifier in at least two modes, including: a first mode including a dedicated connection to the at least one speaker; and a second mode including a direct physical connection with an additional audio amplifier and the dedicated connection to the at least one speaker, where in the first mode and the second mode the amplifier is configured to provide the amplified audio output signal to drive the at least one speaker, and in the second mode the amplifier is configured to forward the at least one input signal to enable the additional audio amplifier to control audio output at an additional speaker.

The disclosure presents a method and an amplifier system for minimizing variation in an acoustical signal caused by variation in gain of an amplifier, comprising a battery for providing a supply voltage to the amplifier, a digital signal processor for providing the acoustical signal to the amplifier, a controller unit receiving an enablement signal when the supply voltage is in an offset mode, and based on the enablement signal requesting a measured voltage during a time period, and a first analog-to-digital converter configured for measuring the supply voltage to the amplifier when receiving the request from the controller unit or the first analog-to-digital converter is configured for measuring the supply voltage to the amplifier continuously, and where variations in the measured voltage relates to variations in the supply voltage during the time period. Furthermore, the controller unit is configured to predict offset modes (i.e. changes) in the supply voltage based on the enablement signals and a fitting of the measured voltages, and wherein the controller unit is configured to generate a compensating signal based on the fitting and transmit the compensating signal to the digital signal processor, the digital signal processor is then configured to minimize variation in the acoustical signal at the output of the amplifier by compensating the variation in gain of the amplifier based on the compensating signal.

The disclosure presents a method and an amplifier system for minimizing variation in an acoustical signal caused by variation in gain of an amplifier, comprising a battery for providing a supply voltage to the amplifier, a digital signal processor for providing the acoustical signal to the amplifier, a controller unit receiving an enablement signal when the supply voltage is in an offset mode, and based on the enablement signal requesting a measured voltage during a time period, and a first analog-to-digital converter configured for measuring the supply voltage to the amplifier when receiving the request from the controller unit or the first analog-to-digital converter is configured for measuring the supply voltage to the amplifier continuously, and where variations in the measured voltage relates to variations in the supply voltage during the time period. Furthermore, the controller unit is configured to predict offset modes (i.e. changes) in the supply voltage based on the enablement signals and a fitting of the measured voltages, and wherein the controller unit is configured to generate a compensating signal based on the fitting and transmit the compensating signal to the digital signal processor, the digital signal processor is then configured to minimize variation in the acoustical signal at the output of the amplifier by compensating the variation in gain of the amplifier based on the compensating signal.

A modular headphone system that can afford the wearer configurable choices of hearing protection and quality sound delivery for music and programming is provided. In an embodiment, a modular headphone includes a headband and an earpiece mounted to the headband. The earpiece comprises a can comprising a speaker, the can secured to the headband. A removable and replaceable music ear cup is removably mountable to the can to overlie the speaker. A removable and replaceable hearing protection/sound amplification (HP/amp) ear cup is removably mountable to the can to overlie the speaker.

A sound signal processing device supplies an output sound signal to an amplification device configured to supply a first sound signal to a high-frequency speaker and a low-frequency speaker. The sound signal processing device includes a high-pass filter, an amplitude limitation circuit, a low-pass filter, and a synthesis circuit. The high-pass filter removes a low-frequency component from an input sound signal to generate a high-frequency sound signal. The amplitude limitation circuit limits an amplitude of the input sound signal at or below a reference value to generate a second sound signal. The reference value corresponds to a clipping voltage of the amplification device. The low-pass filter removes a high-frequency component from the second sound signal to generate a low-frequency sound signal. The synthesis circuit synthesizes the high-frequency sound signal and the low-frequency sound signal to generate the output sound signal.

A sound signal processing device supplies an output sound signal to an amplification device configured to supply a first sound signal to a high-frequency speaker and a low-frequency speaker. The sound signal processing device includes a high-pass filter, an amplitude limitation circuit, a low-pass filter, and a synthesis circuit. The high-pass filter removes a low-frequency component from an input sound signal to generate a high-frequency sound signal. The amplitude limitation circuit limits an amplitude of the input sound signal at or below a reference value to generate a second sound signal. The reference value corresponds to a clipping voltage of the amplification device. The low-pass filter removes a high-frequency component from the second sound signal to generate a low-frequency sound signal. The synthesis circuit synthesizes the high-frequency sound signal and the low-frequency sound signal to generate the output sound signal.

A distributed audio processing system is disclosed, for providing users with the capability of producing a personalized audio mix of a plurality of signals from a plurality of audio sources. The system includes a wireless transmitter for each audio source and, for each user, a wireless receiver. The receiver comprises a programmable audio signal processor configured to process and mix a plurality of audio tracks received via a radio broadcast of a multi-track audio signal comprising the audio signals from the plurality of sources, said processing and mixing being programmable via received commands, instructions and/or parameters. The transmitters are configured to process the audio signals received from their respective sources, according to received commands, instructions and/or parameters. According to an embodiment, a user may provide commands, instructions and/or parameters to any of the receivers and/or transmitters of the system.

A distributed audio processing system is disclosed, for providing users with the capability of producing a personalized audio mix of a plurality of signals from a plurality of audio sources. The system includes a wireless transmitter for each audio source and, for each user, a wireless receiver. The receiver comprises a programmable audio signal processor configured to process and mix a plurality of audio tracks received via a radio broadcast of a multi-track audio signal comprising the audio signals from the plurality of sources, said processing and mixing being programmable via received commands, instructions and/or parameters. The transmitters are configured to process the audio signals received from their respective sources, according to received commands, instructions and/or parameters. According to an embodiment, a user may provide commands, instructions and/or parameters to any of the receivers and/or transmitters of the system.