Abstract: An electrodynamic actuator (1a, 1b) is disclosed, which is designed to be connected to a plate like structure (2) and which comprises a coil arrangement (3a, 3b) with at least one voice coil (4a, 4b), a magnet system (5) with a movable magnetic circuit part (7, 7a . . . 7f) and a static magnetic circuit part (6a . . . 6F) and a spring arrangement (12) coupling the static magnetic circuit part (6a . . . 6F) to the movable magnetic circuit part (7, 7a . . . 7f) and allowing a relative movement between the same. Both the spring arrangement (12) and the magnet system (5) provide a total restoring force (FT) directed towards an idle position (P0) of the movable magnetic circuit part (7, 7a . . . 7f). A part of a total restoring force gradient (?FT/?z) caused by the magnet system (5) is at least 10% of the total restoring force gradient (?FT/?z) in said idle position (P0) of the movable magnetic circuit part (7, 7a . . . 7f).

Abstract: A method for manufacturing an electrodynamic acoustic transducer is disclosed. The electrodynamic acoustic transducer comprises a frame and/or a housing, a membrane, at least one coil and a magnet system, wherein the coil, in a cross sectional view with a coil axis being part of the sectional plane, comprises a plurality of conductive layers formed by an electrical conductor of the coil. The electrical conductor has a rectangular cross section in said cross sectional view, wherein a longer side of the rectangular cross section is substantially perpendicular to the loop axis. According to this method, a stack of conductive layers is made from the electrical conductor by stacking of separate pieces of the electrical conductor and electrically connecting the stacked separate pieces and/or by folding of the electrical conductor.

Abstract: An electrodynamic acoustic transducer, is disclosed, which comprises a frame and/or a housing, a membrane, at least one coil and a magnet system. The coil in a cross sectional view with a coil axis being part of the sectional plane comprises a plurality of conductive layers formed by an electrical conductor of the coil. The electrical conductor has a rectangular cross section in said cross sectional view, wherein a longer side of the rectangular cross section is substantially perpendicular to the loop axis. Furthermore, a method for manufacturing an electrodynamic acoustic transducer of the proposed kind is disclosed. According to this method, a stack of conductive layers is made from the electrical conductor by stacking of separate pieces of the electrical conductor and electrically connecting the stacked separate pieces and/or by folding of the electrical conductor.

Abstract: An electrodynamic actuator (1a, 1b) is disclosed, which is designed to be connected to a plate like structure (2) and which comprises a coil arrangement (3a, 3b) with at least one voice coil (4a, 4b), a magnet system (5) with a movable magnetic circuit part (7, 7a . . . 7f) and a static magnetic circuit part (6a . . . 6F) and a spring arrangement (12) coupling the static magnetic circuit part (6a . . . 6F) to the movable magnetic circuit part (7, 7a . . . 7f) and allowing a relative movement between the same. Both the spring arrangement (12) and the magnet system (5) provide a total restoring force (FT) directed towards an idle position (P0) of the movable magnetic circuit part (7, 7a . . . 7f). A part of a total restoring force gradient (?FT/?z) caused by the magnet system (5) is at least 10% of the total restoring force gradient (?FT/?z) in said idle position (P0) of the movable magnetic circuit part (7, 7a . . . 7f).

Abstract: The invention relates to an electromagnetic actuator, which can be connected to a backside of a plate like structure and which comprises a voice coil, a magnet system and a spring arrangement connecting the voice coil and a movable part of the magnet system. The spring arrangement comprises at least two spiral springs each having at least three spring legs. The spring legs run in radial and tangential direction in a clockwise or counterclockwise winding direction and are rotational symmetric around the coil axis. The winding directions of the spiral springs are chosen in a way that rotations around the coil axis caused by a relative movement between the voice coil and the movable part of the magnet system in the excursion direction are oriented in opposite directions. The invention also relates to an output device with a plate like structure and an electromagnetic actuator connected thereto.

Abstract: A method for manufacturing an electrodynamic acoustic transducer is disclosed. The electrodynamic acoustic transducer comprises a frame and/or a housing, a membrane, at least one coil and a magnet system, wherein the coil, in a cross sectional view with a coil axis being part of the sectional plane, comprises a plurality of conductive layers formed by an electrical conductor of the coil. The electrical conductor has a rectangular cross section in said cross sectional view, wherein a longer side of the rectangular cross section is substantially perpendicular to the loop axis. According to this method, a stack of conductive layers is made from the electrical conductor by stacking of separate pieces of the electrical conductor and electrically connecting the stacked separate pieces and/or by folding of the electrical conductor.

Abstract: A dynamic loudspeaker driver comprising a magnet-system; a membrane; the membrane being movably mounted with respect to the magnet-system; at least one voice coil attached to the membrane and operatively coupled with the magnet-system, wherein the voice coil comprises an upper edge facing the membrane and a lower edge being arranged opposite the upper edge of the voice coil; at least one voice coil extension element comprising an upper surface facing the membrane and a lower surface facing the upper edge of the voice coil, wherein the lower surface of the voice coil extension element is attached the upper edge of the voice coil while the upper surface of the voice coil extension element is attached to the membrane.

Abstract: The invention relates to an electromagnetic actuator, which can be connected to a backside of a plate like structure and which comprises a voice coil, a magnet system and a spring arrangement connecting the voice coil and a movable part of the magnet system. The spring arrangement comprises at least two spiral springs each having at least three spring legs. The spring legs run in radial and tangential direction in a clockwise or counterclockwise winding direction and are rotational symmetric around the coil axis. The winding directions of the spiral springs are chosen in a way that rotations around the coil axis caused by a relative movement between the voice coil and the movable part of the magnet system in the excursion direction are oriented in opposite directions. The invention also relates to an output device with a plate like structure and an electromagnetic actuator connected thereto.

Abstract: An electrodynamic acoustic transducer, is disclosed, which comprises a frame and/or a housing, a membrane, at least one coil and a magnet system. The coil in a cross sectional view with a coil axis being part of the sectional plane comprises a plurality of conductive layers formed by an electrical conductor of the coil. The electrical conductor has a rectangular cross section in said cross sectional view, wherein a longer side of the rectangular cross section is substantially perpendicular to the loop axis. Furthermore, a method for manufacturing an electrodynamic acoustic transducer of the proposed kind is disclosed. According to this method, a stack of conductive layers is made from the electrical conductor by stacking of separate pieces of the electrical conductor and electrically connecting the stacked separate pieces and/or by folding of the electrical conductor.

Abstract: A dynamic loudspeaker driver comprising a magnet-system; a membrane; the membrane being movably mounted with respect to the magnet-system; at least one voice coil attached to the membrane and operatively coupled with the magnet-system, wherein the voice coil comprises an upper edge facing the membrane and a lower edge being arranged opposite the upper edge of the voice coil; at least one voice coil extension element comprising an upper surface facing the membrane and a lower surface facing the upper edge of the voice coil, wherein the lower surface of the voice coil extension element is attached the upper edge of the voice coil while the upper surface of the voice coil extension element is attached to the membrane.