A piezoelectric speaker device that includes an organic polymer piezoelectric film, at least one pair of electrodes provided in contact with the piezoelectric film and the at least one pair of electrodes including a user-side electrode on a first side of the piezoelectric film, an insulation layer on the user-side electrode, a flaw detection electrode line on the insulation layer, and a detection circuit configured to detect whether the flaw detection electrode line is in a normal electric conduction state.

A loudspeaker includes a diaphragm, a frame, an attachment unit, and a fixing member. The frame has a front surface, a mounting surface disposed on a side opposite to the front surface, and a wall surface disposed in a standing manner from the mounting surface. And the frame holds an outer peripheral edge of the diaphragm. The attachment unit includes: a base portion having a top surface facing the mounting surface, a bottom surface on a side opposite to the top surface, a first side surface facing the wall surface, and a second side surface disposed on a side opposite to the first side surface; a first base rib projecting toward the wall surface from the first side surface; a second base rib projecting from the second side surface and extending to the top surface; and a locking portion disposed on a side near the bottom surface of the base portion. The fixing member penetrates the frame from the front surface to the mounting surface and is fixed to the base portion by screwing.

A loudspeaker includes a diaphragm, a frame, an attachment unit, and a fixing member. The frame has a front surface, a mounting surface disposed on a side opposite to the front surface, and a wall surface disposed in a standing manner from the mounting surface. And the frame holds an outer peripheral edge of the diaphragm. The attachment unit includes: a base portion having a top surface facing the mounting surface, a bottom surface on a side opposite to the top surface, a first side surface facing the wall surface, and a second side surface disposed on a side opposite to the first side surface; a first base rib projecting toward the wall surface from the first side surface; a second base rib projecting from the second side surface and extending to the top surface; and a locking portion disposed on a side near the bottom surface of the base portion. The fixing member penetrates the frame from the front surface to the mounting surface and is fixed to the base portion by screwing.

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 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 loudspeaker having a first magnet configured to output a first magnetic field in a first magnet gap, an elongate armature extending through the first magnet gap, a first coil configured to generate a magnetic flux in the armature, a first diaphragm, a first element configured to transfer force and/or movement from the armature to the first diaphragm, a base and a first and a second support element, the first support element connecting the armature to the base at a first longitudinal position at a first side of a predetermined portion along the length of the armature, and the second support element connecting the armature to the base at a second longitudinal position at a second, opposite side of the predetermined portion. The base may flex between a U-shape and an inverted U-shape and may thus provide force to move the diaphragm.

A loudspeaker having a first magnet configured to output a first magnetic field in a first magnet gap, an elongate armature extending through the first magnet gap, a first coil configured to generate a magnetic flux in the armature, a first diaphragm, a first element configured to transfer force and/or movement from the armature to the first diaphragm, a base and a first and a second support element, the first support element connecting the armature to the base at a first longitudinal position at a first side of a predetermined portion along the length of the armature, and the second support element connecting the armature to the base at a second longitudinal position at a second, opposite side of the predetermined portion. The base may flex between a U-shape and an inverted U-shape and may thus provide force to move the diaphragm.

According to an embodiment, a microfabricated structure includes a cavity disposed in a substrate, a first clamping layer overlying the substrate, a deflectable membrane overlying the first clamping layer, and a second clamping layer overlying the deflectable membrane. A portion of the second clamping layer overlaps the cavity.

According to an embodiment, a microfabricated structure includes a cavity disposed in a substrate, a first clamping layer overlying the substrate, a deflectable membrane overlying the first clamping layer, and a second clamping layer overlying the deflectable membrane. A portion of the second clamping layer overlaps the cavity.

A diaphragm of a MEMS microphone is configured to generate a displacement thereof in response to an applied acoustic pressure, and the diaphragm includes a plurality of vent holes having a bent shape to increase the length of the vent holes.