An electronic device may have a housing, a battery, a conductive coil, near-field communications circuitry, amplifier circuitry, and wireless charging circuitry. The housing may have a housing wall. The conductive coil may be adhered to the housing wall. The conductive coil may be coiled around a magnet. The amplifier circuitry may drive audio signals and/or haptic signals onto the conductive coil that cause the conductive coil to vibrate the housing wall. The near-field communications circuitry may convey near-field communications signals through the housing wall using the conductive coil. The wireless charging circuitry may receive wireless power for charging the battery through the housing wall using the conductive coil. If desired, the conductive coil may include a first set of windings that lie within a surface extending along the housing wall and/or a second set of vertically-stacked windings that extend away from the housing wall.

The invention relates to a speaker (1) comprising a coil arrangement (2) with at least two voice coils (3a, 3b), a magnet system (4) and a membrane (10) being fixed to the coil arrangement (2) and the magnet system (4). The membrane (10) has a first compliance (c.sub.1) and together with the coil arrangement (2) causes a first resonance frequency (fres.sub.1) for an oscillation of the membrane (10). In addition, the speaker (1) comprises a second connector (14, 17, 17a, 17b, 24, 25a, 25b) with a second compliance (c.sub.2), which interconnects the voice coils (3a, 3b). The second connector (14, 17, 17a, 17b, 24, 25a, 25b) together with the voice coils (3a, 3b) causes a higher second resonance frequency (fres.sub.2) for the oscillation of the membrane (10). Moreover, the invention relates to an electronic sound signal circuit (18), which is designed to output coil signals (SO1, SO2) having a frequency dependent phase shift (φ). In addition, invention relates to a sound system comprising an electronic sound signal circuit and a speaker of the above kind and to a method for manufacturing a coil arrangement (2).

Techniques are provided for generating sound using a speaker mounted to an enclosure (e.g., speaker cabinet) wherein a gas pressure level (e.g., air pressure level) inside the enclosure is lower than an ambient air pressure level outside the enclosure. The reduced gas pressure level within the enclosure provides an environment with a reduced pressure level at a back side of a speaker cone of the speaker, which enhances a low frequency response for a given speaker size, while also minimizing resonant frequencies and phase cancellation issues which could otherwise occur with conventional speaker systems in which acoustic sound waves are generated at the back side of the speaker cone. A pressure compensation system is utilized counteract a force applied to the front side of the speaker cone as a result of the gas pressure level inside the enclosure being lower than the ambient air pressure level outside the enclosure.

Two coils are wrapped in one of numerous different implementations. In one implementation, the two coils are wrapped about a portion of a bobbin that has at least three flanges. The first coil is disposed about a first portion of the bobbin between the first flange and the second flange, and a second coil is disposed about a second portion of the bobbin between the second flange and the third flange.

A flat plate audio transducer. A front panel and a back panel are connected via a frame. One or more electromagnetic actuators are mounted between the two panels. Voice coils are used as the actuators in some embodiments. Stiffening braces are preferably run between groups of actuators to prevent unwanted resonance phenomena. In some embodiments an actuator array moves both the front and back panels. In other embodiments only one panel is moved.

An audio output system for energizing a multiple voice coil transducer supplies at least two power output signals to the voice coils, a pilot tone generator for generating a pilot tone signal, and a power output circuit. The power output circuit generates power output signals from the pilot tone and the input signal so that the voice coils respond to the input signal with an in-phase electro-mechanical relationship and respond to the pilot tone with an out-of-phase (motion canceling) electro-mechanical relationship, reducing the effect of the pilot town on mechanical movement of the voice coil. A sensing circuit senses electrical signal values at terminals of the at least two voice coils, and a processing circuit detects a response of the output transducer to the pilot tone and determines at least one operating characteristic of the output transducer from the electrical signal values.

An electro-acoustic transducer has an acoustic diaphragm and a voice-coil. The diaphragm defines a first major surface. A flange extends from the diaphragm in a direction opposite the first major surface. The voice-coil has a first plurality of windings positioned adjacent to the acoustic diaphragm and a second plurality of windings positioned distally from the acoustic diaphragm. The flange overlaps the first plurality of windings. The flange and the windings can be adhesively bonded with each other to form a lap joint. The lap joint can transfer force from the voice-coil to the diaphragm.

A magnet system (100) for an electromechanical transducer has a first set (2) of magnets and a second set (4) of magnets. The first set (2) of magnets has a first, inner annular magnet (6) and a first outer, annular magnet (8), and the second set (4) of magnets has a second, inner annular magnet (10) and a second, outer annular magnet (12). The first, inner annular magnet (6) is arranged in the interior of the first outer annular magnet (8), and the second inner annular magnet (10) is arranged in the interior of the second outer annular magnet (12). The magnetic polarity in respect of the first, inner annular magnet (6), the first, outer annular magnet (8), the second, inner annular magnet (10), and of the second, outer annular magnet (12) has a direction (Y) corresponding to a direction perpendicular to the annular extension (X) of the magnets.

A dual function transducer assembly comprising: a magnet motor assembly comprising a first magnet plate and a second magnet plate arranged in parallel to one another along a first axis; a sound output assembly coupled to the magnet motor assembly, the sound output assembly comprising a piston and a voice coil, and wherein the voice coil is arranged to cause a vibration of the piston in a direction parallel to the first axis; and a shaker assembly coupled to the magnet motor assembly, the shaker assembly comprising a first shaker coil and a second shaker coil arranged to cause a vibration of the magnet assembly in a direction parallel to a second axis that is perpendicular to the first axis.

Techniques are provided for generating sound using a speaker mounted to an enclosure (e.g., speaker cabinet) wherein a gas pressure level (e.g., air pressure level) inside the enclosure is lower than an ambient air pressure level outside the enclosure. The reduced gas pressure level within the enclosure provides an environment with a reduced pressure level at a back side of a speaker cone of the speaker, which enhances a low frequency response for a given speaker size, while also minimizing resonant frequencies and phase cancellation issues which could otherwise occur with conventional speaker systems in which acoustic sound waves are generated at the back side of the speaker cone. A pressure compensation system is utilized counteract a force applied to the front side of the speaker cone as a result of the gas pressure level inside the enclosure being lower than the ambient air pressure level outside the enclosure.