A method for determining a voice coil position of a voice coil includes providing a magnetic circuit having a magnetic gap and suspending the voice coil in the magnetic gap, applying a driving signal to the voice coil to produce an electromotive force, providing inductive sensors mechanically coupled to the voice coil, measuring inductive sensor signals based on outputs from the inductive sensors, processing the measured inductive sensor signals by determining at least one inductive sensor signal ratio, and determining a representation of the voice coil position based on the at least one inductive sensor signal ratio. A voice coil system, which can be incorporated in a loudspeaker, is configured to carry out the method.

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.

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.

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.

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.

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.

Aspects of the subject technology relate to electronic devices having speakers. An electronic device may operate the speaker at or near one or more resonance frequencies of the speaker and/or the electronic device. This can allow the electronic device to efficiently eject an occlusion when the speaker is occluded by a fluid or other debris. For example, the electronic device may determine a resonance frequency by obtaining one or more electrical characteristics of an electronic component while the speaker is occluded, determine the resonance frequency based on the obtained electrical characteristic(s), and operate the speaker at a frequency that is based on the resonance frequency to eject the occlusion.

Force transducers for use in electrostatic drivers, including electrostatic 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 having the force transducers can be used at all audio frequencies, including subwoofer frequencies.

Acoustic transducer systems and methods of operating acoustic transducer systems are provided. The methods can involve: receiving an input audio signal; determining a position of a diaphragm; determining a correction factor, a motor force factor, a spring error factor, and a system spring factor based at least on the position of the diaphragm; determining a corrected voice coil current based at least on the input audio signal, the correction factor, the spring error factor, and a velocity of the diaphragm; and applying a corrected audio signal to a voice coil fixed to the diaphragm based at least on the corrected voice coil current, wherein the corrected audio signal corrects the input audio signal to compensate for non-linear characteristics of the acoustic transducer system.