In at least one embodiment, an audio amplifier system is provided. The system includes a loudspeaker and an audio amplifier. The loudspeaker transmits an audio output into a listening environment. The audio amplifier is programmed to receive an audio input signal and to generate an excursion signal corresponding to a first excursion level of the voice coil based on the audio input signal. The audio amplifier is further programmed to limit the excursion signal to reach a maximum excursion level and to determine a target pressure for an enclosure of the loudspeaker based on the maximum excursion level. The audio amplifier is further programmed to generate a target current signal based at least on the target pressure and to convert the target current signal into a target voltage signal to a target driving signal to drive the voice coil to reach the maximum excursion level.

A system for determining the temperature of a voice coil of a speaker includes a first pre-emphasis filter which has an input coupled to receive a digitized current sense signal. The first pre-emphasis filter applies a gain to signal components at a selected frequency band and provides a pre-emphasized current sense signal. The system includes a second pre-emphasis filter which has an input coupled to receive a digitized voltage sense signal. The second pre-emphasis filter applies a gain to the signal components at the selected frequency band and provides a pre-emphasized voltage sense signal. The system includes a first quantizer module configured to map the pre-emphasized signal to a quantized current sense signal, and includes a second quantizer module configured to map the pre-emphasized voltage sense signal to a quantized voltage sense signal.

The present application provides a method of audio signal processing. The method comprises obtaining a voice coil direct current resistance of a speaker. The method further comprises obtaining an audio input signal to be input into the speaker. The method further comprises determining an audio input power based on the voice coil direct current resistance and the audio input signal. The method further comprises obtaining a thermal model of the speaker, and determining a transient power threshold based on the audio input power and the thermal model. The method further comprises determining a power constraint gain based on the audio input power and the transient power threshold. The method further comprises obtaining a voice coil temperature of the speaker. The method further comprises determining a temperature constraint gain based on the voice coil temperature and an upper operating temperature limit of the speaker. The method further comprises adjusting the audio input signal based on the power constraint gain and the temperature constraint gain, to obtain a target signal.

The present disclosure relates to a speaker device including a circuit housing, an ear hook, a rear hook, and a speaker assembly. The speaker assembly may include a headphone core and a housing for accommodating the headphone core, the housing may include a housing panel facing a human body and a housing back opposite to the housing panel, and the headphone core may cause the housing panel and the housing back to vibrate. An absolute value of a difference between a first phase of a vibration of the housing panel and a second phase of a vibration of the housing back may be less than 60 degrees when a frequency of each of the vibration of the housing panel and the vibration of the housing back is between 2000 Hz and 3000 Hz.

A bone conduction speaker is provided herein. The bone conduction speaker may include a magnetic circuit component for providing a magnetic field, a vibration component located in the magnetic field, and a case. At least a part of the vibration component may convert an electrical signal into a mechanical vibration signal. The case may include a case panel facing a human body side and a case back opposite to the case panel, and accommodate the vibration component that causes the case panel and the case back to vibrate. A vibration of the case panel may have a first phase, and a vibration of the case back may have a second phase. When frequencies of the vibration of the case panel and the case back are within 2000 Hz to 3000 Hz, an absolute value of a difference between the first and the second phase(s) may be less than 60 degrees.

A speaker has a magnetic angle sensor that detects the displacement of the vibration system of the speaker. A non-linearity compensation filter compensates for output distortion due to a non-linear parameter of the speaker. A transfer function of a linear inverse filter is applied so that output distortion is eliminated from the displacement, detected by the magnetic angle sensor, of the vibration system. A controller drives the speaker by using a test signal, and measures a response from the detected displacement of the vibration system. If error between the measured response and the theoretical value, theoretically determined from the design specifications, of the response is small, the controller uses the theoretical value, theoretically determined from the design specifications, of the non-linear parameter as an active non-linear parameter and sets, in the non-linearity compensation filter, a transfer function that compensates for distortion in an output due to the active non-linear parameter.

The present technique relates to a signal processing device, method, and a program capable of reducing Doppler distortion. The signal processing device includes: a displacement prediction unit that predicts displacement of a diaphragm of a speaker, in a case where the speaker plays back sound based on an audio signal in which a high-frequency signal and a low-frequency signal are mixed, based on the audio signal; and a correction unit that performs time direction correction on the audio signal by performing interpolation processing using at least three samples of the audio signal, based on the displacement obtained from the predicting and a correction time obtained based on an acoustic velocity. The present technique can be applied in audio playback systems.

A method for determining a direct current impedance of a transducer may include receiving an input signal indicative of an electrical power consumed by the transducer and calculating, by a thermal model of the transducer, the direct current impedance based on the electrical power.

Disclosed are a closed loudspeaker box, a display device including the closed loudspeaker box, and a method for testing the closed loudspeaker box. The closed loudspeaker box includes: a housing; a chamber surrounded by the housing; a through hole penetrating the housing and communicating with the chamber; and a plug, at least a part of the plug is inserted into the through hole, wherein the plug includes a plug main body and a vent hole penetrating the plug main body, and the vent hole communicates the chamber and a space outside the housing.

Electroacoustic drivers that can be utilized in loudspeaker systems that utilize drivers having a magnetic negative spring (MNS) (such as reluctance assist drivers (RAD) and permanent magnet crown (PMC) drivers). The electroacoustic drivers can be used at all audio frequencies, including subwoofer frequencies. The magnetic negative springs of the electroacoustic drivers can cancel, or partially cancel, the large pressure forces on a sound panel (of an audio speaker) so that substantial subwoofer notes can be efficiently and cost effectively produced in small/portable speakers. The electroacoustic drivers can include a stabilizing/centering mechanism to overcome the destabilizing forces of a MNS that are too large for a voice coil alone to produce.