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.

Disclosed herein is a grill-integrated low-pass filter. The grill-integrated low-pass filter includes a conduit-type low-pass filter part in which a sound conduit is formed inside an internal space of a grill, which is a mechanism assembled and used in a housing, in an empty tubular form, and the conduit-type low-pass filter part is integrated with the grill. According to the present invention, there are provided the grill-integrated low-pass filter that is designed in a structure in which the sound conduit is formed inside the internal space of the grill disposed and used in a housing in order to protect a speaker driver, etc. and is thus fabricated in a grill-integrated form, thereby achieving the effects of improving the sound quality of the speaker and reducing characteristic deviations in a low-frequency band.

Disclosed are a directional microphone receiver and sound device. The directional microphone receiver includes: a housing and an electret condenser microphone (ECM), where the housing has a first tuning chamber and a second tuning chamber; a side of the housing is provided with a first sound transmission hole and a second sound transmission hole; the first tuning chamber communicates with the first sound transmission hole, and the second tuning chamber communicates with the second sound transmission hole; the ECM is provided between the first tuning chamber and the second tuning chamber, and has a diaphragm, an upper chamber, and a lower chamber; the diaphragm is provided between the upper chamber and the lower chamber; and the lower chamber communicates with the first tuning chamber, and the upper chamber communicates with the second tuning chamber.

An audio loudspeaker system for reproducing frequencies between 16 Hz and 700 Hz, comprising a loudspeaker housing defining an inner resonance chamber and at least two loudspeaker drivers arranged in the housing and having front faces arranged facing each other in an opposed manner. The housing comprises vertical wall elements arranged with a distance approximately defining a width of the resonance chamber, where each wall element comprises first and second side surfaces and a circumferential edge surface. A first side surface of the wall elements constitutes and inner surface of the housing and partly defines an enclosure of the resonance chamber, and a second side surface of the wall elements constitutes exterior side surfaces of the audio loudspeaker system. The loudspeaker drivers are arranged within substantially hemispherical cups arranged on the second side surfaces of the wall elements and enclosing the loudspeaker drivers in a close manner.

An image recognition-based electric speaker includes a U-shaped iron for increasing magnetic field and improving anti-magnetism, a magnet installed on the U-shaped iron for generating magnetic field, a washer installed on the magnet for increasing the magnetic field and magnetic permeability, a voice coil installed on the washer for electrically conducting power, a voice coil paper tube installed on the voice coil, a damper installed around the voice coil for maintaining the magnetic gap and improving the capability of withstanding power, a box holder mounted around the low-frequency suspension edge, a gasket installed at the lower edge of the box holder for sealing the box holder airtightly, a low-frequency suspension edge disposed around the mid-frequency vibrating plate, a high-frequency anti-dust cap installed on the voice coil paper tube, and a mid-frequency vibrating plate disposed around the anti-dust cap. This invention has the effect of reducing criminal activities.

A speaker box includes an upper shell and a lower shell that define a receiving space, and a speaker unit received in the receiving space and dividing the receiving space into front and rear cavities. The speaker unit includes a diaphragm spaced apart from the upper shell to form a front acoustic cavity. The upper shell is formed with a sound transmitting channel communicating the front acoustic cavity with the outside. The upper shell includes a top wall, and a support wall extending from the top wall towards the lower shell. The speaker box further includes a partition wall extending from the top wall towards the lower shell, and a cover plate extending from the partition wall towards the support wall. The partition wall, the cover plate and the support wall define at least two resonant cavities spaced apart from each other and in communication with the front cavity.

A wearable audio device including first and second transducer modules is provided. The first transducer module may include a first transducer. The first transducer module may further include a first enclosure having a top side defining a first slit and a bottom side defining a second slit. The first enclosure may be configured to guide a first sound pressure through the first slit, and a second sound pressure through the second slit. The second transducer module may include a second transducer. The second transducer module may include a second enclosure having a top side defining a third slit and a bottom side defining a fourth slit. The second enclosure may be configured to guide a third sound pressure through the third slit, and a fourth sound pressure through the fourth slit. The third and fourths slit may be arranged diagonally opposite the first and second slits, respectively.

Disclosed herein is a grill-integrated low-pass filter. The grill-integrated low-pass filter includes a conduit-type low-pass filter part in which a sound conduit is formed inside an internal space of a grill, which is a mechanism assembled and used in a housing, in an empty tubular form, and the conduit-type low-pass filter part is integrated with the grill. According to the present invention, there are provided the grill-integrated low-pass filter that is designed in a structure in which the sound conduit is formed inside the internal space of the grill disposed and used in a housing in order to protect a speaker driver, etc. and is thus fabricated in a grill-integrated form, thereby achieving the effects of improving the sound quality of the speaker and reducing characteristic deviations in a low-frequency band.

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 sound output device includes: a speaker unit that has a sound emitting portion; an attaching member by which the speaker unit is attached to an object; a separating member that is provided between the speaker unit and the attaching member to separate the speaker unit from the attaching member; and a sealing member that is provided between the speaker unit and the attaching member to reduce a sound that is emitted from a side of the speaker unit opposite to the sound emitting portion and is transmitted to a sound emitting portion side. The attaching member has a first portion on a side of the sound emitting portion of the speaker unit, and the first portion of the attaching member has an opening that corresponds to the sound emitting portion.