A conduction receiver utilizing sound transmission through a solid medium includes an outer casing, a vibration reed, a magnet, a washer, a coil, and a lid. The lid covers surfaces of the outer casing to form a sealed first receiving space. The vibration reed, the magnet, the washer, and the coil are all arranged in the first receiving space. A peripheral surface of the vibration reed is coupled to the outer casing. The magnet is arranged at a side of the vibration reed away from a bottom of the outer casing. The washer is arranged at a side of the magnet away from the vibration reed. A first end of the coil is fixed to an inner surface of the lid, and a second end of the coil extends into the first receiving space and is coiled around the magnet and the washer. An electronic device is also provided.

A speaker including a supporting structure, a diffusion membrane that is movable relative to the supporting structure, a motor for actuating the diffusion membrane, including a movable unit relative to the supporting structure, the movable unit being mechanically connected to the diffusion membrane for synchronized movement thereof, and a hydraulic circuit interposed between the movable unit and the diffusion membrane, the diffusion membrane and the movable unit each including a movable piston surface, interacting with a fluid of the hydraulic circuit.

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.

A planar magnetic driver including a radiating surface having a trace-free central region is described. The driver has a magnet defining an acoustic opening on a central axis. A diaphragm of the planar magnetic driver is held by mounts having a mounting profile around the central axis, and the diaphragm includes a radiating surface facing the acoustic opening. An innermost conductive trace on the diaphragm extends around a central region of the radiating surface within a magnetic flux of the magnet such that no conductive traces are on the central region. A radial distance between the innermost conductive trace and the mounting profile is less than another radial distance between the innermost conductive trace and the central axis. Accordingly, an excursion range of the diaphragm along the central axis is greater than a gap distance between the conductive trace and the magnet. Other aspects are also described and claimed.

A flat plate audio transducer. A front panel and a back panel are connected via a frame. One or more electromagnetic actuators are mounted between the two panels. Voice coils are used as the actuators in some embodiments. Stiffening braces are preferably run between groups of actuators to prevent unwanted resonance phenomena. In some embodiments an actuator array moves both the front and back panels. In other embodiments only one panel is moved.

A sound producing structure includes: a frame body, a magnetic circuit system, a first diaphragm, and a second diaphragm. The frame body includes a receiving cavity, and the receiving cavity includes a first opening and a second opening that are located on two opposite sides of the frame body. The magnetic circuit system is located in the receiving cavity, and the magnetic circuit system includes a first magnetic channel and a second magnetic channel that are isolated from each other. The first diaphragm is disposed facing the first opening, a first voice coil is disposed on the first diaphragm, and a portion of the first voice coil extends into the first magnetic channel. The second diaphragm is disposed facing the second opening, a second voice coil is disposed on the second diaphragm, and a portion of the second voice coil extends into the second magnetic channel.

A loudspeaker system, having a good low-frequency response without a large box and effectively improving the efficiency of the loudspeaker system, so as to increase the output sound pressure level of the system, comprises a box and a plurality of loudspeakers arranged in the box and connected in parallel with each other, wherein each of the loudspeakers comprises a frame, a diaphragm arranged on the frame, and a voice coil for driving a vibration of the diaphragm; front surfaces of the diaphragms of the loudspeakers are arranged to face each other; a sound cavity is formed among the front surfaces of the diaphragms, and the sound cavity is in communication with the outside of the box; and each of the frames is located between a rear surface of its corresponding diaphragm and an inner wall of the box.

A transducer assembly comprising: a magnet motor assembly comprising a first magnet plate and a second magnet plate arranged along an axis, a first support plate positioned between inward facing surfaces of the first magnet plate and the second magnet plate, a second support plate positioned along an outward facing surface of the first magnet plate to form a first magnetic gap between the first support plate and the second support plate, and a third support plate positioned along an outward facing surface of the second magnet plate to form a second magnetic gap between the first support plate and the third support plate; a voice coil coupled to the magnet motor assembly, wherein the voice coil is positioned around the first support plate and within the first magnetic gap and the second magnetic gap; and a piston coupled to the voice coil, wherein the piston is operable to vibrate in a direction parallel to the axis.

A flat plate audio transducer. A front panel and a back panel are connected via a frame. One or more electromagnetic actuators are mounted between the two panels. Voice coils are used as the actuators in some embodiments. Stiffening braces are preferably run between groups of actuators to prevent unwanted resonance phenomena. In some embodiments an actuator array moves both the front and back panels. In other embodiments only one panel is moved. The flat plate transducer is configured to mount on a room wall in a position that is conventionally used for decorative items such as artwork.

A planar magnetic driver including a radiating surface having a trace-free central region is described. The driver has a magnet defining an acoustic opening on a central axis. A diaphragm of the planar magnetic driver is held by mounts having a mounting profile around the central axis, and the diaphragm includes a radiating surface facing the acoustic opening. An innermost conductive trace on the diaphragm extends around a central region of the radiating surface within a magnetic flux of the magnet such that no conductive traces are on the central region. A radial distance between the innermost conductive trace and the mounting profile is less than another radial distance between the innermost conductive trace and the central axis. Accordingly, an excursion range of the diaphragm along the central axis is greater than a gap distance between the conductive trace and the magnet. Other aspects are also described and claimed.