The present invention provides for an electroacoustic driver for use within an explosion proof loudspeaker or sounder and comprising a housing enclosing a coil of an electromagnet, the coil operatively coupled to an electromagnet core, a diaphragm located outside the housing for generating audible sound waves, a magnetic element located outside the housing and coupled to the diaphragm, wherein the electromagnet core extends through a wall of the housing from inside to outside of the housing to interact with the said magnetic element to cause movement of the diaphragm.

The present invention provides for an electroacoustic driver for use within an explosion proof loudspeaker or sounder and comprising a housing enclosing a coil of an electromagnet, the coil operatively coupled to an electromagnet core, a diaphragm located outside the housing for generating audible sound waves, a magnetic element located outside the housing and coupled to the diaphragm, wherein the electromagnet core extends through a wall of the housing from inside to outside of the housing to interact with the said magnetic element to cause movement of the diaphragm.

An arrangement for generating vibration according to an electrical input signal includes a first permanent magnet arrangement including a first permanent magnet, a frame including magnetic material, a second permanent magnet configured to be arranged between the first permanent magnet and the frame and to be coupled with the frame, one or more portion of the frame extending at least in one direction over an edge area of the second permanent magnet. The second permanent magnet is further configured to face, at a distance, the first permanent magnet such that a magnetic interaction between the first permanent magnet and the second permanent magnet causes a first force to a surface of an apparatus, wherein the frame is configured to be magnetized by the second permanent magnet in order to cause magnetic interaction between the one or more portion of the frame and the first permanent magnet arrangement in order to cause a second force to the surface having an opposite direction compared with the first force.

Various embodiments of a speaker and a method of forming such speaker are disclosed. The speaker includes a frame having a first major surface, a second major surface, and an opening disposed between the first and second major surfaces; a cone disposed adjacent the first major surface of the frame; and an adhesive layer disposed on at least a portion of the second major surface of the frame. The adhesive layer occludes the opening of the frame.

Various embodiments of a speaker and a method of forming such speaker are disclosed. The speaker includes a frame having a first major surface, a second major surface, and an opening disposed between the first and second major surfaces; a cone disposed adjacent the first major surface of the frame; and an adhesive layer disposed on at least a portion of the second major surface of the frame. The adhesive layer occludes the opening of the frame.

Loudspeaker unit with a membrane (2) and a plurality of drive units (5) driving the membrane (2). Each of the plurality of drive units (5) has n voice coils (3) and at least n+1 magnets (4), n being an integer larger than or equal to 1. The magnets (4) have an axial magnetization and are stacked in axial direction with similar pole parts of adjacent ones of the at least n+1 magnets facing each other. The at least n+1 magnets (4) are separated in the stack over a magnet separation distance (d.sub.m), the magnet separation distance (d.sub.m) being substantially equal to a width (w.sub.s) in the stack direction of the at least n voice coils (3).

The present invention relates to a bridge-edge-type high-resolution electromagnetic speaker, wherein a coil and a permanent magnet, which are a pair of magnetic circuits provided at upper and lower portions of a vibration module, are stacked vertically. It is possible to manufacture a high-resolution loudspeaker having a wide range of applicability from a small-sized earphone with a plug-in type to a portable TV and an automobile. And a damper of a diaphragm of a vibration module may be formed as a magnetic material damper and the coil is directly contacted without any space between the coils, it is possible to transmits the magnetic energy of the coil to the diaphragm without loss and contribute to the amplitude expansion of the diaphragm. As a result, efficiency is increased and the bass reproduction limit frequency is expanded.

The present invention relates to a bridge-edge-type high-resolution electromagnetic speaker, wherein a coil and a permanent magnet, which are a pair of magnetic circuits provided at upper and lower portions of a vibration module, are stacked vertically. It is possible to manufacture a high-resolution loudspeaker having a wide range of applicability from a small-sized earphone with a plug-in type to a portable TV and an automobile. And a damper of a diaphragm of a vibration module may be formed as a magnetic material damper and the coil is directly contacted without any space between the coils, it is possible to transmits the magnetic energy of the coil to the diaphragm without loss and contribute to the amplitude expansion of the diaphragm. As a result, efficiency is increased and the bass reproduction limit frequency is expanded.

The present invention relates to an ultra slim high-resolution electromagnetic speaker with bridge-edge, wherein a pair of magnetic circuits stacked on the upper and lower sides of the vibration module and a permanent magnet are provided in a horizontal arrangement structure and a permanent magnet is disposed inside the coil, so that an ultra slim speaker may be obtained and the inner magnetic field of the permanent magnet whose distance between the opposite poles of the permanent magnet is approximated by the limiter may be used as the driving bias of the diaphragm to reduce the magnetoresistance and increase the efficiency.

The present invention relates to an ultra slim high-resolution electromagnetic speaker with bridge-edge, wherein a pair of magnetic circuits stacked on the upper and lower sides of the vibration module and a permanent magnet are provided in a horizontal arrangement structure and a permanent magnet is disposed inside the coil, so that an ultra slim speaker may be obtained and the inner magnetic field of the permanent magnet whose distance between the opposite poles of the permanent magnet is approximated by the limiter may be used as the driving bias of the diaphragm to reduce the magnetoresistance and increase the efficiency.