A temperature detecting and controlling integration device for the micro speaker is provided. After the filter receives an input signal, the power amplifier adjusts the power amplification, and the multi-frequency detection signal is generated with the waveform generator. The extracted signal is generated to drive the micro speaker to emit a sound signal. Afterwards, the voltage signals are extracted at two ends of the coil and the temperature signal is obtained by converting, capturing, and integrating to pass the temperature value to the external device, and the temperature value of the non-linear temperature-controlling unit is analyzed to adjust the compensation gain in real time. The smoothly control of speaker temperature and stable playback of the sound signals is played that can be achieved.

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.

Audio circuitry, comprising: a speaker driver operable to drive a speaker based on a speaker signal; a current monitoring unit operable to monitor a speaker current flowing through the speaker and generate a monitor signal indicative of that current; and a microphone signal generator operable, when external sound is incident on the speaker, to generate a microphone signal representative of the external sound based on the monitor signal and the speaker signal.

A speaker includes a frame having a receiving space, a vibration unit received in the receiving space, and a magnetic circuit unit for driving the vibration unit to vibrate and emit sound. The vibration unit includes a first diaphragm configured to vibrate and emit sound, and a voice coil for driving the first diaphragm to vibrate and emit sound. The speaker further includes a centering support sandwiched between the first diaphragm and the voice coil. In the speaker according to the present disclosure, by sandwiching the centering support between the voice coil and the first diaphragm, a positional conflict between the centering support and the main magnet is avoided, the main magnet can have an increased size, thereby enhancing the space utilization and sensitivity of the speaker, and improving the acoustic performance of the speaker.

Techniques, methods, systems, and other mechanisms for measuring the excursion of a speaker while being actively driven. Measuring excursion can involve attaching a flexible printed coil (FPC), including a sense coil, to the speaker, and monitoring an induced current as produced though the sense coil, and further detecting that violation of an excursion limit for the speaker may likely occur.

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 method for generating a prediction curve for acoustic load of a loudspeaker, the loudspeaker including a horn and a diaphragm, one end of the horn is defined as a throat, and the outside of the other end of the horn is free space, wherein a sound wave from the diaphragm passes through the throat and gradually diffuses to the free space outside the other end of the horn, includes defining a cross section or a surface, where the cross section is a cross section of the throat, and the surface is a surface of the diaphragm; integrating a sound pressure value of the cross section or the surface to obtain an effective sound pressure, or integrating acoustic energy of the cross section or the surface to obtain a radiated sound power; and generating the prediction curve according to the effective sound pressure or the radiated sound power, where the prediction curve is an acoustic impedance curve or an acoustic power curve.

An audio processor for a multi voice coil acoustic transducer is described. The audio processor may receive or generate an audio signal. The audio signal may have one or more phase shifts applied. The audio signal may be used to drive a first coil of a dual voice coil acoustic transducer. The phase-shifted audio signals may drive the other coils of a multi voice-coil acoustic transducer. The phase shift is selected so that the phase difference between the audio signal driving each voice coil may result in destructive interference in the multi voice-coil loudspeaker resulting in reduced or no acoustic output due to the audio signal.

Systems, methods, and apparatus are provided for recording high output power levels of sound at low sound pressure levels. For example, an apparatus comprises an enclosure, a speaker disposed within the enclosure, a microphone disposed within the enclosure, and an evacuation port. The evacuation port is configured to connect to a system that reduces a pressure level within the enclosure to a level that is less than an ambient air pressure level outside the enclosure. The enclosure is sealed or otherwise configured to provide a sealed enclosure, to maintain the reduced air pressure within the enclosure. The speaker can be driven by an amplifier at high output power levels to generate a distorted sound of an amplified electric musical instrument for recording purposes, while the reduced pressure level within the enclosure serves to attenuate the sound pressure level and perceived loudness which emanates from the speaker.

A vehicle is provided and includes a first tire, a second tire, and a detector that is configured to detect an air pressure of the first tire. A vibration generator is configured to generate vibration in the second tire. A controller is configured to operate the vibration generator to cause the second tire vibrate when the air pressure of the first tire satisfies a predetermined normal condition.