A flat plate bass loudspeaker comprising a flat plate diaphragm, at least three driving units and a housing. The driving unit comprises a voice coil unit and a magnetic circuit unit; the voice coil units are dispersedly coupled to one side of the diaphragm near the housing; mounting holes for accommodating and fixing the magnetic circuit units, and voice outlet holes penetrating through the housing are arranged on the housing; the number and position of the mounting holes are corresponding to those of voice coils attached to the spherical top of the diaphragm; and ratio of the total area of the voice outlet holes to the orthographic projection area of the diaphragm on the housing is in a range less than 0.9. The flat plate bass loudspeaker provided by the present invention can avoid the problems occurred in thick and heavy voice coils and excessive magnet performance.

A damper and a speaker apparatus includes the damper, which suppresses damage to an oscillatory system from an excessive input signal, enabling an efficiency increase of the speaker apparatus. As a damper has a planar surface, undue deformation of the oscillatory system due to an excessive input signal is suppressed, and damage to the oscillatory system can be suppressed. Furthermore, since the deformation of a corrugation portion by a normal input signal is hardly prevented, a reduction in sound pressure of the speaker apparatus with respect to an input signal is suppressed, enabling an increase in efficiency. Furthermore, the planar surface is extended at a height in a thickness direction different from that of an attachment portion. Thus, rising portions are deformed when a voice coil bobbin is oscillated, enabling suppression of rupture of the damper in the vicinity of a boundary between the planar surface and the attachment portion.

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.

The present disclosure provides a speaker, including a frame, a vibration system, a magnetic circuit system, the vibration system includes a first diaphragm and a second diaphragm which are fixed to two opposite sides of the frame, a first voice coil to drive the first diaphragm to vibrate, and a second voice coil assembly to drive the second diaphragm to vibrate. The vibration system further includes a first elastic wave assembly and a second elastic wave assembly which are fixed to the frame and are spaced from each other. The first elastic wave assembly and the second elastic wave assembly are in staggered distribution and antiphase vibration. By means of the staggered distribution of the first elastic wave assembly and the second elastic wave assembly, the first elastic wave assembly and the second elastic wave assembly make reasonable use of an internal space of the speaker.

A loudspeaker driver or tweeter (e.g., 100, 200 or 300) having a voice coil connected with a loudspeaker diaphragm (e.g., 106, 206 or 306), having a substantially circular diaphragm portion which is connected with or rests upon a voice coil attachment segment (e.g., 104, 204, 304). The diaphragm also includes a first central elliptical (non-circular-shaped) inner roll portion (e.g., 112, 212, 312) defining a central recessed area and a second, outer elliptical (non-circular-shaped) roll portion (e.g., 108, 208, 308) so the central portion and the outer roll portion that have substantially elliptical edge circumferences with substantially circular central peripheral edges to define diaphragm segments with a varying radial Chord lengths having non-uniform diameter dimensions (inside diameter to outside diameter) and when in use, the excursion of the diaphragm is controlled such that any breakup modes are minimized and the associated resonances are minimized.

The invention relates to an electrodynamic transducer having a magnetic mass connected to a frame with first and second axially offset suspensions. The suspensions permit translational displacement of the magnetic mass with respect to the frame and have multiple springs. The direction of orientation of the springs of the first suspension is opposite that of the springs of the second suspension, such that each suspension blocks the axial rotation of the other suspension.

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.

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.

An electrodynamic actuator for a speaker or an electrodynamic acoustic transducer in general is disclosed, which comprises at least one voice coil, a magnet system and an arm arrangement of a plurality of arms connecting the at least one voice coil and the magnet system or at least a movable part thereof so that a relative movement between these parts is allowed. The arms are made of a metal core, which at least partly is coated with a coating structure having at least one coating metal layer consisting of a different material than the metal core.

An electrodynamic actuator for a speaker or an electrodynamic acoustic transducer in general is disclosed, which comprises at least one voice coil, a magnet system and an arm arrangement of a plurality of arms connecting the at least one voice coil and the magnet system or at least a movable part thereof so that a relative movement between these parts is allowed. The arms are made of metal with a fatigue strength of at least 370 N/mm.sup.2 or an ultimate tensile strength of at least 1100 N/mm.sup.2.