An acoustic device includes a piezoelectric element, an attachment member to which the piezoelectric element is attached, and a spacer. The piezoelectric element includes first and second principal surfaces opposing each other. The attachment opposes the first principal surface. The spacer is disposed between the piezoelectric element and the attachment member in such a manner as to form an acoustic space between the piezoelectric element and the attachment member. The spacer includes an adhesive layer including a principal surface in contact with the first principal surface and a principal surface in contact with the attachment member.

Intra-concha earphones are disclosed. In an embodiment, an intra-concha earphone includes a housing having a rear space divided into a back volume, a bass duct, and a vent chamber between a driver and a rear wall. The vent chamber may be acoustically coupled with the back volume through both an acoustic port and the bass duct. Furthermore, the vent chamber may be acoustically coupled with a surrounding environment through a vent port, which may be a sole acoustic opening in the rear wall. Thus, sound emitted by the driver may propagate through the acoustic port and the bass duct to meet in the vent chamber before being discharged through the vent port to the surrounding environment. Other embodiments are also described and claimed.

This invention discloses a kind of speaker structure with a loading hole. A characteristic is that it includes an active cavity that has a cone hole and a loading hole; a loudspeaker is sealed and secured on the said cone hole; the said active cavity is connected to the outside air through the said loading hole; the cone of the said loudspeaker has one side which is connected to the free space; another characteristic of this invention is that it includes a driven cavity that is connected to the said active cavity through the said loading hole; the cross-sectional area of the said loading hole is smaller than the cross-sectional area of the air passage on its either side; further, it is not larger than ⅔ the effective area of all the vibration units in the said active cavity; also, the volume of the said active cavity does not exceed half the total volume of the said active cavity and driven cavity. The loading hole constitutes a loading component which improves the transient response of the speaker body. To a great extent, it solves the contradiction between frequency response and transient effect at low sound frequencies. It lowers the requirements for the loudspeaker and simultaneously allows the frequency response and transient effect for the entire system at low sound frequencies to be handled relatively independently. This causes the loudspeaker cost to be reduced.

An amplifier and an electronic device using the same are provided. The amplifier includes a first acoustic box, a speaker, a second acoustic box, a connection tube and at least one sound guide tube. The first acoustic box has a first sound hole. The speaker faces the first acoustic box. The second acoustic box has at least one second sound hole. The connection tube connects the first acoustic box and the second acoustic box. The sound guide tube is connected to the second sound hole.

Provided is a speaker box, including a housing having a receiving space and a speaker unit received therein. The housing extends into the receiving space to form a support wall. The speaker unit is supported by and fixed to the support wall. The housing has a sound output hole. The speaker unit includes a frame, a vibration system and magnetic circuit unit fixed to the frame, and a front cover covering the frame. The front cover is supported by and fixed to the support wall. The front cover includes a main body portion located above the vibration system, a side edge portion and a fixed portion covering the frame. The fixed portion is supported by and fixed to the support wall. The front cover has a through hole running through both the main body portion and the side edge portion. The speaker box has excellent sound quality.

A bone conduction speaker includes a housing, a vibration board and a transducer. The transducer is located in the housing, and the vibration board is configured to contact with skin and pass vibration. At least one sound guiding hole is set on at least one portion of the housing to guide sound wave inside the housing to the outside of the housing. The guided sound wave interfaces with the leaked sound wave, and the interfacing reduces a sound pressure level of at least a portion of the leaked sound wave. A frequency of the at least a portion of the leaked sound wave is lower than 4000 Hz.

A speaker comprises a housing, a transducer residing inside the housing, and at least one sound guiding hole located on the housing. The transducer generates vibrations. The vibrations produce a sound wave inside the housing and cause a leaked sound wave spreading outside the housing from a portion of the housing. The at least one sound guiding hole guides the sound wave inside the housing through the at least one sound guiding hole to an outside of the housing. The guided sound wave interferes with the leaked sound wave in a target region. The interference at a specific frequency relates to a distance between the at least one sound guiding hole and the portion of the housing.

A speaker comprises a housing, a transducer residing inside the housing, and at least one sound guiding hole located on the housing. The transducer generates vibrations. The vibrations produce a sound wave inside the housing and cause a leaked sound wave spreading outside the housing from a portion of the housing. The at least one sound guiding hole guides the sound wave inside the housing through the at least one sound guiding hole to an outside of the housing. The guided sound wave interferes with the leaked sound wave in a target region. The interference at a specific frequency relates to a distance between the at least one sound guiding hole and the portion of the housing.

An earphone body includes an internal chamber, a transducer housed in the internal chamber, a first tuned vent and a second tuned vent. The transducer has a front surface facing a direction of insertion of the earphone body in use and a rear surface 6B. The internal chamber provides a proximal acoustic volume adjacent the front surface of the transducer and a distal acoustic volume adjacent the rear surface of the transducer. The first tuned vent and the second tuned vent each extend between the distal acoustic volume and the ambient environment and are adapted to provide fluid communication between the distal acoustic volume and the ambient environment. The first tuned vent is tuned to a first frequency and the second tuned vent is tuned to a second frequency, the first frequency being lower than the second frequency.

An open audio device including an acoustic radiator that emits front-side acoustic radiation from its front side, and emits rear-side acoustic radiation from its rear side. A front acoustic cavity receives front-side acoustic radiation and comprises at least one front sound-emitting opening, and a rear acoustic cavity receives rear-side acoustic radiation and comprises at least one rear sound-emitting opening. The front and rear acoustic cavities each have a fundamental frequency. The fundamental frequencies are within one octave of each other.