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.

In an example, a speaker device may include a first transducer and a second transducer. The first transducer may include a first diaphragm, a first magnetic circuit, and a first voice coil disposed in a magnetic gap of the first magnetic circuit to cause vibration of the first diaphragm. The second transducer may include a second diaphragm, a second magnet circuit, and a second voice coil disposed in a magnetic gap of the second magnetic circuit to cause vibration of the second diaphragm. Further, the speaker device may include a magnetic plate having a first surface coupled to the first transducer and a second surface coupled to the second transducer. The first surface is opposite to the second surface.

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.

An example magnet assembly for a loudspeaker includes a first permanent magnet with a cuboid shape, the first magnet encompassing a central opening, and a second permanent magnet with a cuboid shape, the second magnet positioned coaxially within the opening of the first magnet and forming a rectangular-ring shaped first gap therebetween, the first and second magnets being axially poled in opposed directions. The assembly further includes a soft-magnetic base plate connected across one side of the first and second magnets, a soft-magnetic first pole piece having a first face and positioned on the first magnet, and a soft-magnetic second pole piece having a second face and positioned on the second magnet. The first pole piece and the second pole piece form a rectangular-ring shaped second gap between the first and second faces such that magnetic flux is focused in the second gap.

A dual-diaphragm differential capacitive microphone includes: a back plate, a first diaphragm, and a second diaphragm. The first diaphragm is insulatively supported on a first surface of the back plate, where the back plate and the first diaphragm form a first variable capacitor. The second diaphragm is insulatively supported on a second surface of the back plate, where the back plate and the second diaphragm form a second variable capacitor. The back plate is provided with at least one connecting hole. The second diaphragm is provided with a recess portion recessed towards the back plate, where the recess portion passes through the connecting hole and is connected to the first diaphragm. The dual-diaphragm differential capacitive microphone achieves a higher signal-to-noise ratio.

A transducer assembly having a frame; a dual diaphragm and voice coil assembly suspended from the frame, the dual diaphragm and voice coil assembly having a first diaphragm and a first voice coil attached thereto and a second diaphragm and a second voice coil attached thereto, wherein the first voice coil and the second voice coil are between the first diaphragm and the second diaphragm, and the first diaphragm and the second diaphragm are operable to move in opposite directions along an axis of vibration; a magnet assembly positioned within the frame, the magnet assembly having a first magnet and a second magnet positioned between the first diaphragm and the second diaphragm; and a rigid support member dimensioned to fixedly connect the magnet assembly to the frame.

A single-magnet double-tone-circuit coaxial loudspeaker includes a shell, a U iron, a magnet, a spring washer, a first diaphragm assembly, a second diaphragm assembly, an upper cover and a terminal plate. A single magnet+spring washer+U iron magnetic circuit is extended to be two upper-lower coaxial magnetic circuits, therefore, the first diaphragm assembly and the second diaphragm assembly which are electrically connected to the terminal plate generate a double-magnetic-circuit feature by sharing a single-magnet system. High frequency and low frequency wave bands are driven independently, such that high frequency and low frequency portions can achieve a better sound resolution effect. The complementation of the two reduces distortion, thus improves the overall acoustic performance of the loudspeaker.

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 speaker transducer, comprising a speaker membrane and two drive members connected to an outer membrane circumference of the speaker membrane for driving the speaker membrane. A substantially rigid support member is connected to each of the two drive members and extends there between, wherein the support member is connected to and extends along the speaker membrane.

A linear motor magnet assembly for use in a loudspeaker unit, with a fixed base actuator component and a membrane actuating element, the membrane actuating element having a linear excursion axis. A first auxiliary magnetic element and a second auxiliary magnetic element are present, the first auxiliary magnetic element providing a first auxiliary spatial magnetic field with a major axis aligned with the linear excursion axis. The second auxiliary magnetic element is fixedly connected to the membrane actuating element of the linear motor magnet assembly and has a second auxiliary spatial magnetic field, the second auxiliary magnetic field overlapping the first auxiliary spatial magnetic field and being substantially similarly oriented as the first auxiliary spatial magnetic field over a first predetermined excursion range of the linear motor magnet assembly.