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.

An electronic speaker comprising: a device housing defining an interior cavity and including a sidewall extending around the interior cavity between an upper portion and a lower portion of the device housing; first and second sound channels formed at opposing locations along the sidewall, each of the first and second sound channels comprising a plurality of openings formed through the sidewall; a passive radiator array comprising first and second passive radiators disposed within the interior cavity, spaced apart from each other in an opposing relationship and aligned to project sound through the first and second sound channels; an active driver disposed in the device housing and configured to generate sound in response to an electrical signal, the active driver comprising driver housing disposed at least partially between the first and second passive radiators, a magnet disposed within the driver housing, a voice coil and a diaphragm facing downwards towards the lower surface of the device housing; and an annular sound channel disposed along the bottom portion of the device housing adjacent to the diaphragm of the active driver.

A hinge system having at least three hinge joints, consisting each of a hinge element and an associated contact member. The contact surface of the hinge element of each hinge joint moves relative to the contact surface of the associated contact member to enable rotatable oscillation of the hinge joint about a common axis of rotation during operation. The contact surface of each contact member is convexly curved and the hinge joints comprise convex surfaces facing in different directions to enhance operation of the hinge system. Multiple convex surfaces are preferably formed on a relatively rigid component to reduce manufacturing complexity and improve operation. The hinge system is particularly suited for audio transducer applications, but may also be used in other applications, such as in other electromechanical devices.

A hinge system having at least three hinge joints, consisting each of a hinge element and an associated contact member. The contact surface of the hinge element of each hinge joint moves relative to the contact surface of the associated contact member to enable rotatable oscillation of the hinge joint about a common axis of rotation during operation. The contact surface of each contact member is convexly curved and the hinge joints comprise convex surfaces facing in different directions to enhance operation of the hinge system. Multiple convex surfaces are preferably formed on a relatively rigid component to reduce manufacturing complexity and improve operation. The hinge system is particularly suited for audio transducer applications, but may also be used in other applications, such as in other electromechanical devices.

Ultrasonic transducers that include membrane films and perforated baseplates. An ultrasonic transducer includes a baseplate having a conductive surface with a plurality of apertures, openings, or perforations formed thereon or therethrough, and a membrane film having a conductive surface. The membrane film is positioned adjacent to the apertures, openings, or perforations formed on or through the baseplate. By applying a voltage between the conductive surface of the membrane film and the conductive surface of the baseplate, an electrical force of attraction can be created between the membrane film and the baseplate. Varying this applied voltage can cause the membrane film to undergo vibrational motion. The dimensions corresponding to the size and/or shape of the apertures, openings, or perforations formed on or through the baseplate can be varied so that different regions of the baseplate produce different frequency responses, allowing the net bandwidth of the ultrasonic transducer to be increased.

The invention relates to audio transducers, such as loudspeaker, microphones and the like, and includes improvements in or relating to hinge systems for rotational action audio transducers. The hinge systems of the invention being configured to operatively support a diaphragm in use, and comprising a hinge assembly having one or more hinge joints, wherein each hinge joint comprises a hinge element and a contact member. The contact member comprises a contact surface and the configuration is such that during operation each hinge joint is configured to allow the hinge element to move relative to the associated contact member, while maintaining a substantially consistent physical contact with the contact surface. The hinge assembly biases the hinge element towards the contact surface. Preferably the hinge assembly is configured to apply a biasing force to the hinge element of each joint toward the associated contact surface, compliantly. Various applications and implementations are described and envisaged for the audio transducer embodiments including, for example, personal audio devices such as headphones, earphones and the like.

The invention relates to audio transducers, such as loudspeaker, microphones and the like, and includes improvements in or relating to hinge systems for rotational action audio transducers. The hinge systems of the invention being configured to operatively support a diaphragm in use, and comprising a hinge assembly having one or more hinge joints, wherein each hinge joint comprises a hinge element and a contact member. The contact member comprises a contact surface and the configuration is such that during operation each hinge joint is configured to allow the hinge element to move relative to the associated contact member, while maintaining a substantially consistent physical contact with the contact surface. The hinge assembly biases the hinge element towards the contact surface. Preferably the hinge assembly is configured to apply a biasing force to the hinge element of each joint toward the associated contact surface, compliantly. Various applications and implementations are described and envisaged for the audio transducer embodiments including, for example, personal audio devices such as headphones, earphones and the like.

The electrodynamic loudspeaker (10), comprising: a fixed frame (12), a motor including a fixed base (14) connected to the fixed frame (12) and a part (16) movable axially relative to the fixed base (14) along an axis (A-A′), a convex membrane (18), the convexity of which is oriented toward the outside of the loudspeaker (10), and a truss (20) connecting the convex membrane (18) and the moving part (16). The truss (20) comprises an inner ring (46) and an outer ring (48) that are coaxial, connected to one another by radial pillars (50) and a crown (52) for fastening to one end (53) of the moving part (16), the convex membrane (18) being fastened bearing on the inner and outer rings (46, 48).

In a subcutaneous microphone used in medical devices, a structure is introduced that constrains the motion of the diaphragm during normal operation of the microphone. In one embodiment, a raised portion, such as a pole or pillar is placed in the chamber at the middle of the diaphragm. The raised portion may contact one or both of the bottom surface of the chamber and the underside of the membrane, and generally acts to reduce the amount of deflection experienced by the membrane.

In a subcutaneous microphone used in medical devices, a structure is introduced that constrains the motion of the diaphragm during normal operation of the microphone. In one embodiment, a raised portion, such as a pole or pillar is placed in the chamber at the middle of the diaphragm. The raised portion may contact one or both of the bottom surface of the chamber and the underside of the membrane, and generally acts to reduce the amount of deflection experienced by the membrane.