Loudspeaker enclosures are disclosed that support improved acoustic radiation efficiency at low audible frequencies without compromising acoustic radiation efficiency at mid and high audible frequencies. Embodiments include enclosures having a primary chamber and a secondary chamber acoustically coupled to the primary chamber via a passive radiator. The geometrical characteristics of the secondary chamber and the corresponding air plenum are tailored for enhanced efficiency at low frequencies.

The present disclosure provides an acoustic output apparatus including one or more status sensors, at least one low-frequency acoustic driver, at least one high-frequency acoustic driver, at least two first sound guiding holes, and at least two second sound guiding holes. The status sensors may detect status information of a user. The low-frequency acoustic driver may generate at least one first sound, a frequency of which is within a first frequency range. The high-frequency acoustic driver may generate at least one second sound, a frequency of which is within a second frequency range including at least one frequency exceeding the first frequency range. The first and second sound guiding holes may output the first and second spatial sound, respectively. The first and second sound may be generated based on the status information, and may simulate a target sound coming from at least one virtual direction with respect to the user.

The present disclosure provides an acoustic output apparatus including one or more status sensors, at least one low-frequency acoustic driver, at least one high-frequency acoustic driver, at least two first sound guiding holes, and at least two second sound guiding holes. The status sensors may detect status information of a user. The low-frequency acoustic driver may generate at least one first sound, a frequency of which is within a first frequency range. The high-frequency acoustic driver may generate at least one second sound, a frequency of which is within a second frequency range including at least one frequency exceeding the first frequency range. The first and second sound guiding holes may output the first and second spatial sound, respectively. The first and second sound may be generated based on the status information, and may simulate a target sound coming from at least one virtual direction with respect to the user.

According to certain embodiments, a microphone array having a plurality of microphone elements is calibrated by ensonifying the microphone array at a first direction relative to the microphone array with a first acoustic signal to concurrently generate a first set of audio signals from two or more of the microphone elements and processing the first set of audio signals to calibrate the two or more microphone elements. One or more other sets of audio signals can be generated by ensonifying the microphone array with one or more other acoustic signals at one or more other directions relative to the microphone array, where the two or more microphone elements are calibrated using the first set and the one or more other sets of audio signals. The calibration process can be performed outside of an anechoic chamber using one or more acoustic sources located outside or inside the microphone array.

Embodiments of this application provide a speaker module and a portable electronic device. The speaker module includes a first speaker module and a second speaker module. The first speaker module includes a first housing and a first speaker monomer accommodated in the first housing, and the first speaker monomer has a first diaphragm. The second speaker module includes a second housing and a second speaker monomer accommodated in the second housing, and the second speaker monomer has a second diaphragm. The first speaker module and the second speaker module are sequentially disposed in a vertical direction, and a vibration direction of the first diaphragm is opposite to a vibration direction of the second diaphragm, so that momentum variations (mv) Δ of the speaker module are offset against each other, thereby resolving a problem that a vibration feeling is strong when the speaker module works.

A two-channel balance method and an electronic device using the same are provided. The two-channel balance method includes the following steps. A gain-frequency information of a two-channel signal is adjusted. A sampling delay information of the two-channel signal is calculated according to a distance information among a sound receiving unit, a left speaker unit and a right speaker unit. A forward test audio file or a surround test audio file is generated according to the sampling delay information. A phase offset information is estimated according to at least the forward test audio file or the surround test audio file. A phase offset direction information is determined. A phase information of the two-channel signal is adjusted according to the phase offset information and the phase offset direction information.

A two-channel balance method and an electronic device using the same are provided. The two-channel balance method includes the following steps. A gain-frequency information of a two-channel signal is adjusted. A sampling delay information of the two-channel signal is calculated according to a distance information among a sound receiving unit, a left speaker unit and a right speaker unit. A forward test audio file or a surround test audio file is generated according to the sampling delay information. A phase offset information is estimated according to at least the forward test audio file or the surround test audio file. A phase offset direction information is determined. A phase information of the two-channel signal is adjusted according to the phase offset information and the phase offset direction information.

In an exemplary embodiment, a system is provided that includes a sensor, a computer memory, and a processor. The sensor is configured to be disposed on a vehicle, and is configured to obtain sound or vibration data for the vehicle. The computer memory is configured to store a plurality of known signatures pertaining to a plurality of different types of vehicle theft events. The processor is configured to: compare a signature of the data with the plurality of known signatures stored in the computer memory; and determine whether a vehicle theft event is occurring based on the comparing of the signature of the data with the plurality of known signatures.

The present disclosure relates to an acoustic output apparatus. The acoustic output apparatus comprising: at least one low-frequency acoustic driver that outputs sound from at least two first sound guiding holes; at least one high-frequency acoustic driver that outputs sound from at least two second sound guiding holes; and a controller configured to cause the low-frequency acoustic driver to output sound in a first frequency range, and cause the high-frequency acoustic driver to output sound in a second frequency range, wherein the second frequency range includes frequencies higher than the first frequency range.

The present disclosure relates to an acoustic output apparatus. The acoustic output apparatus comprising: at least one low-frequency acoustic driver that outputs sound from at least two first sound guiding holes; at least one high-frequency acoustic driver that outputs sound from at least two second sound guiding holes; and a controller configured to cause the low-frequency acoustic driver to output sound in a first frequency range, and cause the high-frequency acoustic driver to output sound in a second frequency range, wherein the second frequency range includes frequencies higher than the first frequency range.