Abstract: A tool for arranging voice coil leadouts in a microspeaker comprises an expanding collet constructed and arranged for positioning at an interior of a bobbin having an inner diameter, the expanding collet including a hole that extends through an interior in a longitudinal direction of the expanding collet; a center pin extending through the hole of the expanding collet, the expanding collet applying a force against the inner diameter of the bobbin in response to a position of the center pin in the hole of the expanding collet relative to the interior of the expanding collet; and a forming mandrel including a hole that extends through an interior in a longitudinal direction of the forming mandrel. The expanding collet extends through the hole in, and coaxial with, the forming mandrel. The expanding collet rotates the bobbin about the longitudinal direction of the expanding collet relative to the forming mandrel to form helical leadout regions of a voice coil about the bobbin.

Abstract: A tool for arranging voice coil leadouts in a microspeaker comprises an expanding collet constructed and arranged for positioning at an interior of a bobbin having an inner diameter, the expanding collet including a hole that extends through an interior in a longitudinal direction of the expanding collet; a center pin extending through the hole of the expanding collet, the expanding collet applying a force against the inner diameter of the bobbin in response to a position of the center pin in the hole of the expanding collet relative to the interior of the expanding collet; and a forming mandrel including a hole that extends through an interior in a longitudinal direction of the forming mandrel. The expanding collet extends through the hole in, and coaxial with, the forming mandrel. The expanding collet rotates the bobbin about the longitudinal direction of the expanding collet relative to the forming mandrel to form helical leadout regions of a voice coil about the bobbin.

Abstract: Various implementations include loudspeaker drivers. In some aspects, an electro-acoustic driver includes: a cup section; a core section at least partially housed in the cup section, the core section including: a primary magnet; and a coin adjacent to the primary magnet; a bobbin surrounding the core section between the cup section and the core section, where the bobbin and the core section define an inner magnetic gap; a coil surrounding the bobbin and a portion of the core section; and a ferrofluid located at the inner magnetic gap, where the driver has an outer diameter less than or equal to approximately 10 millimeters.

Abstract: A tool for arranging voice coil leadouts in a microspeaker comprises a mandrel having a top surface on which a bobbin and voice coil are positioned during formation of helicoidal leadout regions of the voice coil, a bobbin alignment feature for positioning at an inner diameter of the bobbin; a sleeve alignment element at a bottom region of the bobbin alignment feature, the sleeve alignment element having a first surface on which a sleeve of the microspeaker is positioned during the formation of the helicoidal leadout regions, and a gluing ring positioned about the mandrel and on a second surface of the sleeve alignment element for providing guide paths for distal ends of the leadout end regions extending in a direction from the mandrel to the sleeve alignment element.

Abstract: Various implementations include loudspeaker drivers. In some aspects, an electro-acoustic driver includes: a cup section; a core section at least partially housed in the cup section, the core section including: a primary magnet; and a coin adjacent to the primary magnet; a bobbin surrounding the core section between the cup section and the core section, where the bobbin and the core section define an inner magnetic gap; a coil surrounding the bobbin and a portion of the core section; and a ferrofluid located at the inner magnetic gap, where the driver has an outer diameter less than or equal to approximately 10 millimeters.

Abstract: A diaphragm and suspension for an electroacoustic transducer are formed by depositing a layer of compliant material on a first surface of a solid substrate and removing material from a second surface of the solid substrate. The removal leaves a block of substrate material suspended within an inner perimeter of an outer support ring of the substrate material by the compliant material, the block providing the diaphragm.

Abstract: A diaphragm and suspension for an electroacoustic transducer are formed by depositing a layer of compliant material on a first surface of a solid substrate and removing material from a second surface of the solid substrate. The removal leaves a block of substrate material suspended within an inner perimeter of an outer support ring of the substrate material by the compliant material, the block providing the diaphragm.

Abstract: A tool for arranging voice coil leadouts in a microspeaker comprises an expanding collet constructed and arranged for positioning at an interior of a bobbin having an inner diameter, the expanding collet including a hole that extends through an interior in a longitudinal direction of the expanding collet; a center pin extending through the hole of the expanding collet, the expanding collet applying a force against the inner diameter of the bobbin in response to a position of the center pin in the hole of the expanding collet relative to the interior of the expanding collet; and a forming mandrel including a hole that extends through an interior in a longitudinal direction of the forming mandrel. The expanding collet extends through the hole in, and coaxial with, the forming mandrel. The expanding collet rotates the bobbin about the longitudinal direction of the expanding collet relative to the forming mandrel to form helical leadout regions of a voice coil about the bobbin.

Abstract: A solid piston having a closed shape is attached to a solid support surrounding the piston and corresponding in shape to the shape of the piston by a layer of compliant material adhered to a top surface of the piston and a top surface of the support. The layer of compliant material includes an open central area exposing the top surface of the piston through the open area. An assembly for an electroacoustic transducer includes a piston, which is an elliptical plate of silicon having a flat top surface and serving as the diaphragm, an elliptical support ring of silicon surrounding the piston and separated from the piston by a gap, and a layer of compliant material adhered to a top surface of the support ring and to the top surface of the piston, suspending the piston in the gap. An elliptical or cylindrical motor is coupled to the piston.

Abstract: A tool for arranging voice coil leadouts in a microspeaker comprises a mandrel having a top surface on which a bobbin and voice coil are positioned during formation of helicoidal leadout regions of the voice coil, a bobbin alignment feature for positioning at an inner diameter of the bobbin; a sleeve alignment element at a bottom region of the bobbin alignment feature, the sleeve alignment element having a first surface on which a sleeve of the microspeaker is positioned during the formation of the helicoidal leadout regions, and a gluing ring positioned about the mandrel and on a second surface of the sleeve alignment element for providing guide paths for distal ends of the leadout end regions extending in a direction from the mandrel to the sleeve alignment element.

Abstract: A tool for arranging voice coil leadouts in a microspeaker comprises an expanding collet constructed and arranged for positioning at an interior of a bobbin having an inner diameter, the expanding collet including a hole that extends through an interior in a longitudinal direction of the expanding collet; a center pin extending through the hole of the expanding collet, the expanding collet applying a force against the inner diameter of the bobbin in response to a position of the center pin in the hole of the expanding collet relative to the interior of the expanding collet; and a forming mandrel including a hole that extends through an interior in a longitudinal direction of the forming mandrel. The expanding collet extends through the hole in, and coaxial with, the forming mandrel. The expanding collet rotates the bobbin about the longitudinal direction of the expanding collet relative to the forming mandrel to form helical leadout regions of a voice coil about the bobbin.

Abstract: A tool for arranging voice coil leadouts in a microspeaker comprises a mandrel having a top surface on which a bobbin and voice coil are positioned during formation of helicoidal leadout regions of the voice coil, a bobbin alignment feature for positioning at an inner diameter of the bobbin; a sleeve alignment element at a bottom region of the bobbin alignment feature, the sleeve alignment element having a first surface on which a sleeve of the microspeaker is positioned during the formation of the helicoidal leadout regions, and a gluing ring positioned about the mandrel and on a second surface of the sleeve alignment element for providing guide paths for distal ends of the leadout end regions extending in a direction from the mandrel to the sleeve alignment element.

Abstract: A tool for arranging voice coil leadouts in a microspeaker comprises an expanding collet constructed and arranged for positioning at an interior of a bobbin having an inner diameter, the expanding collet including a hole that extends through an interior in a longitudinal direction of the expanding collet; a center pin extending through the hole of the expanding collet, the expanding collet applying a force against the inner diameter of the bobbin in response to a position of the center pin in the hole of the expanding collet relative to the interior of the expanding collet; and a forming mandrel including a hole that extends through an interior in a longitudinal direction of the forming mandrel. The expanding collet extends through the hole in, and coaxial with, the forming mandrel. The expanding collet rotates the bobbin about the longitudinal direction of the expanding collet relative to the forming mandrel to form helical leadout regions of a voice coil about the bobbin.

Abstract: A tool for arranging voice coil leadouts in a microspeaker comprises a mandrel having a top surface on which a bobbin and voice coil are positioned during formation of helicoidal leadout regions of the voice coil, a bobbin alignment feature for positioning at an inner diameter of the bobbin; a sleeve alignment element at a bottom region of the bobbin alignment feature, the sleeve alignment element having a first surface on which a sleeve of the microspeaker is positioned during the formation of the helicoidal leadout regions, and a gluing ring positioned about the mandrel and on a second surface of the sleeve alignment element for providing guide paths for distal ends of the leadout end regions extending in a direction from the mandrel to the sleeve alignment element.

Abstract: A diaphragm and suspension for an electroacoustic transducer are formed by depositing a layer of compliant material on a first surface of a solid substrate and removing material from a second surface of the solid substrate. The removal leaves a block of substrate material suspended within an inner perimeter of an outer support ring of the substrate material by the compliant material, the block providing the diaphragm.

Abstract: A method of fabrication of submicron wide suspended structures. The method includes depositing a layer of glassy material under tensile stress on crystalline silicon, patterning the layer of glassy material with a masking layer having a pattern, the masking layer protecting the layer of glassy material along the pattern, selectively removing the layer of glassy material in areas of the layer of glassy material not protected by the masking layer; and anisotropically etching the crystalline silicon to create at least a pit extending into the crystalline silicon and at least partially under the layer of glassy material to release a suspended structure comprising glassy material.