A loudspeaker comprising two acoustic diaphragms mounted to face in axially-opposed directions, two voice coils each having an axis and an axial length and being configured to reciprocate along its axis to drive one of the diaphragms, the axes being substantially parallel and both axes passing through both diaphragms, and at least one magnet forming part of a chassis assembly configured to provide two axially-extending gaps, one for each of the voice coils to reciprocate within, wherein the at least one magnet and the chassis assembly are adapted so that magnetic flux flows across the gaps in opposite directions, and wherein when in use the diaphragms are at their predetermined maximum negative excursions the voice coils overlap in the axial direction by between 10% and 90% of their average axial length, and wherein when in use the diaphragms are in a relaxed position, between their maximum negative and positive excursions, the voice coils do not overlap in the axial direction.

Aspects of the subject technology relate to electronic devices having speakers with resonators, such as Helmholtz resonators, acoustically coupled to the front volume of the speaker. A speaker module for an electronic device may include multiple resonators, including a first resonator that is acoustically separate from, and at least partially disposed within a second resonator. An acoustic barrier between the first resonator and the second resonator may have a liquid resistance that is different from a liquid resistance that is provided between the first resonator and a back volume of the speaker module and/or between an external environment of the speaker. In one or more implementations, a third resonator may be provided, that is spatially separated from first and second nested and/or adjacent resonators.

An acoustic device comprising: an enclosure defining an acoustic port and an acoustic pathway between the acoustic port and a transducer coupled to the enclosure; and an array of attenuators acoustically coupled to the acoustic pathway to absorb ultrasonic acoustic waves.

The present disclosure relates to a bone conduction speaker and its compound vibration device. The compound vibration device comprises a vibration conductive plate and a vibration board, the vibration conductive plate is set to be the first torus, where at least two first rods inside it converge to its center; the vibration board is set as the second torus, where at least two second rods inside it converge to its center. The vibration conductive plate is fixed with the vibration board; the first torus is fixed on a magnetic system, and the second torus comprises a fixed voice coil, which is driven by the magnetic system. The bone conduction speaker in the present disclosure and its compound vibration device adopt the fixed vibration conductive plate and vibration board, making the technique simpler with a lower cost; because the two adjustable parts in the compound vibration device can adjust both low frequency and high frequency area, the frequency response obtained is flatter and the sound is broader.

The present disclosure provides a sound leakage reduction device. The sound leakage reduction device may include an energy conversion structure, a vibration structure, and a housing. The housing may include a vibration cavity and at least one resonance cavity. The energy conversion structure may be located in the vibration cavity and connected with the vibration structure. The at least one resonance cavity may communicate with the vibration cavity through at least one communication hole. A volume of each resonance cavity may be smaller than a volume of the vibration cavity.

The present disclosure provides an earphone with a duct unit dividing a pressure equilibrium hole and a back hole. The earphone includes a driver unit including a frame, a magnetic circuit, a voice coil, a diaphragm configured to reproduce sound, and a pressure equilibrium hole configured to improve a pressure difference between front and rear sides of the driver unit, and a back hole configured to smooth vibration of the diaphragm. A housing allows the driver unit to be installed therein and includes a vent hole. A duct unit provided in the housing adjusts a size of a back volume in the housing and provides a flow path from the pressure equilibrium hole to the vent hole.

The present invention relates to a loudspeaker including a uniform enclosure having front portion, side portions and back portion defining an inner volume, the front portion is formed as a waveguide surface and includes at least one driver in the waveguide surface and is capable of radiating the main acoustic power of the loudspeaker to direction of first acoustic axis, and an at least one additional driver attached to the enclosure, the additional driver is attached inside the enclosure such that a sub volume is formed inside the inner volume, the sub volume limited by the driver, spacers between the driver and the front portion, and the front portion of the enclosure, at least one first port is adapted to open from the sub volume to ambient volume either to side portion or back portion of the enclosure, and at least one resonator including at least one resonator cavity acoustically connected to the sub volume, the resonator being tuned to at least one of unwanted resonances of the sub volume. In accordance with the invention the resonator is formed as a separate unit connected to the uniform enclosure.

Disclosed herein is a cone arranged speaker. The cone arranged speaker includes: a speaker unit; an enclosure accommodating the speaker unit in at least one surface and having an empty space therein; and a conical reflector formed as a cone inside the enclosure, provided to surface-reflect a sound wave propagating from the speaker unit, including a vertex, a circular planar portion, and a side surface portion connecting the vertex and the planar portion, and provided as at least one conical reflector.

A hearing device includes an acoustic transducer having a membrane configured to generate sound waves, a housing enclosing a first chamber and a second chamber acoustically coupled by the membrane, a sound outlet configured to release sound waves from the first chamber into the ear canal, and an acoustic port acoustically coupling the second chamber to an ambient environment outside the ear canal.

A mobile terminal is provided, including a housing (21) and a speaker (10). The speaker (10) includes a box (11) and a sound generation unit (12). The box (11) includes a first cover body (117), a second cover body (118), and a cover plate (13). A first chamber is formed between the sounding unit (12) and the inner bottom wall of the first cover body, and a sound hole (113) is disposed in the first cavity (111). A second cavity (112) is formed between the sound generation unit (12) and the second cover body (118). The sound generation unit (12) includes a diaphragm (123). A resonant cavity (114) with a through hole (116) on one side is formed in the first cover body (117), the cover plate (13) covers the through hole (116), and a microhole (115) is disposed. Airflow enters the second cavity (112) through the microhole (115).