The present disclosure discloses a sound device comprising: a frame; a vibration system supported on the frame; a magnetic system driving the vibration system for sound generation supported on the frame; the magnetic system comprises a main magnet, a sub-magnet and a magnetic gap formed by spacing of the main magnet and the sub-magnet; the vibration system includes a diaphragm fixed to the frame and a coil driving the diaphragm for sound generation, the coil is at least partially inserted in the magnetic gap; the coil includes a first coil and a second coil both in a shape of ring, one end of the first coil is fixed to the side of the diaphragm near the magnetic system, one end of the second coil is fixed to the end of the first coil near the magnetic system, and the first coil and the second coil are insulated from each other. The present disclosure provides a sound device with adjustable voice coil position and good acoustic performance.

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.

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.

A loudspeaker using a semiconductor voice coil includes a vibrating assembly and a magnetic force assembly. The magnetic force assembly and the vibrating assembly are arranged at an interval. The vibrating component includes a diaphragm and the semiconductor voice coil. The semiconductor voice coil is arranged on a side of the diaphragm. The magnetic force assembly and the semiconductor voice coil are arranged on the same side of the diaphragm. A magnetic gap is defined in the magnetic force assembly. The semiconductor voice coil is arranged in the magnetic gap. The magnetic field lines in the magnetic gap are perpendicular to the direction of current in the semiconductor voice coil. An electronic device including the loudspeaker is also disclosed.

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.

A method for avoiding an offset of a membrane (3) of an electrodynamic acoustic transducer (1) having two voice coils (7, 8) is presented, wherein a control voltage (U.sub.CTRL) is applied to at least one of the voice coils (7, 8) until the electromotive force (U.sub.emf1) of the first coil (7) or a parameter derived thereof and the electromotive force (U.sub.emf2) of the second coil (8) or a parameter derived thereof substantially reach a predetermined relation. Furthermore, an electronic offset compensation circuit (12) is presented, which performs the above application of a control voltage (U.sub.CTRL). Finally, the invention relates to a transducer system with a transducer (1) and an electronic offset compensation circuit (12) connected to the transducer (1).

Disclosed is a sound transducer, which can be assembled, integrated or installed primarily in the consumer, pro audio, installation and automotive sectors on land, water and air with minimal space requirements, use of materials and weight. The transducer includes a ring sound wave shaper having a very flat, thin multi-layered, flexible membrane, which generates point-shaped or ring-shaped sound within the membrane diameter.

An improved wireless communications earplug for use with a magnetic field transmitter. The wireless earplug has a receiver made of a coil of wire on a magnetic bobbin, mounted in close proximity or in contact with a magnetic case of a speaker. The magnetic case of the speaker serves to increase the magnetic flux through the receiver and improves the efficiency of the earplug. The speaker is acoustically coupled to an eartip, and the earplug may be molded into a custom earplug body.

A driver for a loudspeaker including an inner magnet disposed within a housing, an outer magnet disposed within the housing radially outward of the inner magnet, an inner voice coil having a first diameter, an outer voice coil having a second diameter, the second diameter being larger than the first diameter, where poles of the inner and outer magnets are oppositely disposed, where the inner magnet is configured to contribute only to a magnetic circuit of the inner voice coil, and where the outer magnet is configured to contribute to the magnetic circuit of the inner voice coil and to a magnetic circuit of the outer voice coil.

A linear actuator may include a movable element having a plurality of permanent magnets stacked in a direction of an axis line; a stationary element comprising a plurality of coils surrounding a circumferential section of the permanent magnets, the plurality of coils being placed along the axis line; and viscous elastic members inserted between the movable element and the stationary element. The plurality of permanent magnets are arranged such that, among adjacent permanent magnets of the plurality of permanent magnets, sides of the adjacent permanent magnets facing each other have a same polarity. The viscous elastic members are provided at a plurality of locations being separate in the direction of the axis line, in a space sandwiched in a radial direction by the movable element and the stationary element.