A receiver assembly comprising a first and a second receiver housing and a spout. The second receiver housing is positioned over a first sound outlet port of the first receiver housing and the spout is positioned over a second outlet port of the second receiver housing. An acoustic duct is located between the first and second receiver housing acoustically connecting the first sound outlet port to the spout and is provided with an acoustic mass.

A loudspeaker includes an enclosure including a resonance chamber and an acoustic emission aperture for communication of the resonance chamber with the outside, and a plurality of speaker units including a first speaker unit arranged in a first direction and a second speaker unit arranged in a second direction, and the plurality of speakers being accommodated in the enclosure in a non-coaxial arrangement. Front slit spaces of the plurality of speaker units are in communication with the resonance chamber.

A loudspeaker system is provided in which a passive radiator and a driver are connected to one another within a speaker enclosure by an acoustic coupler having a coupler opening such that the driver and the passive radiator are located in different planes.

In one embodiment, an apparatus comprises i) an audio transducer; ii) an audio driver plate having an ear-facing side and a non-ear-facing side; iii) a rigid housing substantially circumferentially surrounding the audio driver plate without substantially covering the ear-facing side and non-ear-facing side of the audio driver plate; iv) a front plate mounted on the ear-facing side of the audio driver plate and spaced apart from the audio driver plate; and v) a fixing gasket affixed to the non-ear-facing side of the audio driver plate. In addition, the front plate is adapted to be compressed against an ear-facing portion of an audio transducer holding device and the fixing gasket adapted to be compressed against a non-ear-facing portion of the audio transducer holding device, whereby the audio transducer is adapted to be held within the audio transducer holding device by compressive force on both the fixing gasket and the front plate.

A passive radiator is provided for use in a loudspeaker system in which the passive radiator and a driver are connected to one another within a speaker enclosure by an acoustic coupler having a coupler opening such that the driver and the passive radiator are located in different planes.

A dynamic microphone that enables taking a long propagation path of a sound wave on a back side of a diaphragm, and by which unidirectivity can be obtained even at a low frequency. The dynamic microphone includes: a dynamic microphone unit; and an air chamber provided on a back side of a diaphragm of the dynamic microphone unit, wherein the air chamber is folded back to make a propagation path of a sound wave on the back side of the diaphragm long, a plurality of acoustic resistors is arranged in the air chamber at intervals to each other in a direction of the propagation path of a sound wave, and acoustic resistance values of the plurality of acoustic resistors become higher as the propagation path of a sound wave goes away from the diaphragm.

In one embodiment, an apparatus comprises i) an audio transducer; ii) an audio driver plate having an ear-facing side and a non-ear-facing side; iii) a rigid housing substantially circumferentially surrounding the audio driver plate without substantially covering the ear-facing side and non-ear-facing side of the audio driver plate; iv) a front plate mounted on the ear-facing side of the audio driver plate and spaced apart from the audio driver plate; and v) a fixing gasket affixed to the non-ear-facing side of the audio driver plate. In addition, the front plate is adapted to be compressed against an ear-facing portion of an audio transducer holding device and the fixing gasket adapted to be compressed against a non-ear-facing portion of the audio transducer holding device, whereby the audio transducer is adapted to be held within the audio transducer holding device by compressive force on both the fixing gasket and the front plate.

A loudspeaker device having housing and an acoustic transducer is disclosed. The housing has a transducer space for the acoustic transducer, and a back volume space. The back volume filled with a sound adsorber material and a foam material. The sound adsorber material in the back volume space is configured to virtually increase the size of the back volume space, and shift the resonant frequency of the back volume space. The foam material separates the sound adsorber from the transducer space and facilitates gas exchange and air flow within the back volume space and between the sound adsorber and the transducer space. The foam material is configured in different arrangements to facilitate the gas exchange and air flow.

A loudspeaker system is provided in which a passive radiator and a driver are connected to one another within a speaker enclosure by an acoustic coupler having a coupler opening such that the driver and the passive radiator are located in different planes.

In one embodiment, an apparatus comprises i) an audio transducer; ii) an audio driver plate having an ear-facing side and a non-ear-facing side; iii) a rigid housing substantially circumferentially surrounding the audio driver plate without substantially covering the ear-facing side and non-ear-facing side of the audio driver plate; iv) a front plate mounted on the ear-facing side of the audio driver plate and spaced apart from the audio driver plate; and v) a fixing gasket affixed to the non-ear-facing side of the audio driver plate. In addition, the front plate is adapted to be compressed against an ear-facing portion of an audio transducer holding device and the fixing gasket adapted to be compressed against a non-ear-facing portion of the audio transducer holding device, whereby the audio transducer is adapted to be held within the audio transducer holding device by compressive force on both the fixing gasket and the front plate.