An electroacoustic transducer includes: a diaphragm; a magnetic circuit having a magnetic gap; a frame that holds the diaphragm and the magnetic circuit; a voice coil having one end portion positioned within the magnetic gap and the other end portion coupled to the diaphragm; and a low friction material that is disposed in a sliding portion formed by the voice coil and the magnetic circuit, and includes polymer compounds swollen with liquid.

Electroacoustic drivers that can be utilized in loudspeaker systems that utilize drivers having a magnetic negative spring (MNS) (such as reluctance assist drivers (RAD) and permanent magnet crown (PMC) drivers). The electroacoustic drivers can be used at all audio frequencies, including subwoofer frequencies. The magnetic negative springs of the electroacoustic drivers can cancel, or partially cancel, the large pressure forces on a sound panel (of an audio speaker) so that substantial subwoofer notes can be efficiently and cost effectively produced in small/portable speakers. The electroacoustic drivers can include a stabilizing/centering mechanism to overcome the destabilizing forces of a MNS that are too large for a voice coil alone to produce.

Electroacoustic drivers that can be utilized in loudspeaker systems that utilize drivers having a magnetic negative spring (MNS) (such as reluctance assist drivers (RAD) and permanent magnet crown (PMC) drivers). The electroacoustic drivers can be used at all audio frequencies, including subwoofer frequencies. The magnetic negative springs of the electroacoustic drivers can cancel, or partially cancel, the large pressure forces on a sound panel (of an audio speaker) so that substantial subwoofer notes can be efficiently and cost effectively produced in small/portable speakers. The electroacoustic drivers can include a stabilizing/centering mechanism to overcome the destabilizing forces of a MNS that are too large for a voice coil alone to produce.

Force transducers for use in electrostatic drivers, including electrostatic drivers that can be utilized in loudspeaker systems that utilize drivers having a magnetic negative spring (MNS) (such as reluctance assist drivers (RAD) and permanent magnet crown (PMC) drivers). The electroacoustic drivers having the force transducers can be used at all audio frequencies, including subwoofer frequencies.

A speaker includes a basket; a diaphragm, supported on the basket through a surround; and a voice coil, including a cup-shaped support connected to the basket through a damper. An upper periphery of the cup-shaped support includes protrusion portions in contact with a lower surface of the diaphragm and grooves spaced apart from the diaphragm. The grooves extend in radial directions of the cup-shaped support to form air passages.

Planar loudspeaker comprising a planar sound panel (10), a mounting (12), at least one drive unit (14) for driving the sound panel (10), said drive unit preferably being attached to the mounting (12), and at least one stabilizing device (22) for stabilizing a movement of the sound panel (10), wherein the stabilizing device (22) is arranged between the sound panel (10) and the mounting (12) and comprises at least a stroke section (28), which is configured so as to be movable, flexible and/or elastic, and at least one centering device (36) for centering the sound panel (10) and/or at least a part of the drive unit (14), wherein the centering device (36) is arranged in a different plane than the stabilizing device (22) and comprises at least a stroke section (28), which is configured so as to be movable, flexible and/or elastic.

Disclosed are a yoke assembly having a magnetic field aggregation structure and a two-way receiver having the same. The yoke assembly for a two-way receiver provided in a two-way receiver having two speaker units sharing a portion of a magnetic field, includes a yoke including a cylindrical portion having a circular bottom surface and a side wall and a flange portion extending externally from an upper end of the side wall of the cylindrical portion and a first magnetically permeable plate attached to an upper surface of the flange portion.

A speaker includes a basket; a diaphragm, supported on the basket through a surround; and a voice coil, including a cup-shaped support connected to the basket through a damper. An upper periphery of the cup-shaped support includes protrusion portions in contact with a lower surface of the diaphragm and grooves spaced apart from the diaphragm. The grooves extend in radial directions of the cup-shaped support to form air passages.

A vibration speaker may include a vibration plate fixed to a housing, a vibrator mounted in the housing to vibrate in a vibration direction of the vibration plate and having a magnet forming a magnetic field, a voice coil member configured to vibrate the vibration plate through interaction of the magnet with the vibrator, and a vibration transmission member configured to support the voice coil member in a state of being fixed to an internal surface of the vibration plate and transmit vibration of the voice coil member to the vibration plate, wherein the vibration transmission member includes a spacing support portion fixed to the voice coil member to be spaced from the internal surface of the vibration plate, and a vibration transmission portion protruding from the spacing support portion to be fixed to the internal surface of the vibration plate.

One embodiment provides a slim acoustic transducer with a diaphragm including a hole that is substantially centered on a vertical axis of the diaphragm. The hole has a first horizontal width. A voice coil has a ring shape that is disposed at least partially within the hole and substantially centered on the vertical axis. The ring shape has an outer and inner horizontal width. The outer horizontal width is smaller than or equal to the first horizontal width of the hole. A column structure is disposed at least partially within the ring shape and substantially centered on the vertical axis. The column structure has a second horizontal width that is smaller than or equal to the inner horizontal width of the ring shape. The column structure includes an upper magnet, a middle plate disposed below the upper magnet and a lower magnet disposed below the middle plate.