MacBook Speaker Design for Enhanced Audio

A method and system for enhancing audio output from compact speakers in electronic devices, such as wearable devices, by generating audio signals at the device's resonant frequency. The system determines the resonant frequency of the speaker in real-time based on measured electrical characteristics, such as impedance or current, and generates audio output at that frequency to achieve maximum loudness. The system can also detect occlusions, such as water or debris, and use the resonant frequency to eject the occlusion.

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A method for enhancing audio output from a compact speaker in an electronic device, such as a wearable device, by generating audio content at resonant frequencies determined in real-time based on measured electrical characteristics of the speaker's components. The method involves obtaining electrical characteristics of the speaker's components, determining the resonant frequencies, and generating audio output at those frequencies to achieve maximum loudness. The method can also be used to eject occlusions from the speaker by operating it at its resonant frequency.

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A moving-magnet motor for driving an actuating surface, such as a speaker diaphragm, with large excursion and low distortion. The motor includes a closed magnetic circuit that focuses magnetic flux density on a stationary coil, with a moving magnet assembly comprising a magnet and a flux concentrating member that define a gap around the coil. The moving magnet assembly is connected to the actuating surface and translates along the coil to drive its movement, while maintaining a dominant magnetic flux density region that enables large excursion without reverse magnetic field disturbance.

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Dual function transducer that can be used as both an electroacoustic transducer (e.g., loudspeaker) and a tactile transducer (e.g., shaker). The transducer has a single magnet motor assembly that accommodates both the loudspeaker components (e.g., piston and voice coil) and shaker components (e.g., shaker coil) so that both functions can be achieved using a single transducer. The magnetic system design enables the utilisation of two functions by directing the magnetic field into two or more sets of high magnetic field density. One set is used by the vibration function, and the other set by the loudspeaker function.

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A technique to improve perceived audio quality in multi-driver speaker systems by coordinated gain reduction across channels to prevent clipping and distortion. When a channel like the woofer is about to overload, instead of just limiting that channel, it also reduces gain on another channel like the tweeter to prevent overall sound from tilting towards the unlimited channel. This maintains a balanced response during loud playback.

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A two-way integrated speaker system that combines a moving coil woofer and a piezoelectric tweeter into a single compact speaker module. The moving coil woofer generates low frequency sounds while the thin piezoelectric tweeter handles high frequencies. The piezoelectric tweeter uses piezoelectricity to convert electrical signals into vibrations. It has high resonance frequencies, low displacement, and generates no heat like coil speakers. By integrating the woofers and tweeters into a single module, it saves space compared to separate speakers.

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Internal speaker design for thin electronic devices that maximizes speaker volume while minimizing enclosure thickness. The speaker enclosure has thin walls supported by internal ribs to prevent vibration. The speaker module is positioned within the device's internal volume and fluidly connected to the speaker enclosure. This allows the speaker volume to be increased without enlarging the enclosure. The speaker module can have multiple drivers with opposite diaphragm movement phases to provide full sound. The thin enclosure walls and compact design enable higher speaker volume in limited device spaces.

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Planar magnetic speaker driver with improved central diaphragm motion and acoustic performance. The driver has conductive traces on the diaphragm that extend around a central region near the center. The traces are further outward on the perimeter. This allows the central region to be trace-free and radially inward from the magnets. This allows the diaphragm to deflect more in the center due to the wider gap there. It also enables acoustic radiation through the central opening without obstruction. This improves excursion and reduces distortion compared to covering the center with traces.

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Coating the interior walls of a loudspeaker's back volume with a highly porous, acoustically active coating to improve sound quality. The coating contains a zeolite adsorbent and a binder that forms a porous, irregular matrix with connected convex shapes and concave connectors. The coating adsorbs and desorbs gases due to its porosity, which causes the back volume to behave as if it's larger than it actually is. This improves the speaker's low-frequency output without physically increasing the back volume size.

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An audio speaker design with expandable fillers in the back volume to improve loudspeaker performance. The speaker has a permeable partition dividing the back volume into two cavities, a rear cavity behind the driver and an adsorption cavity. An expandable filler expands when triggered to reduce membrane vibration forces. An acoustic filler of adsorbing beads in the adsorption cavity absorbs back volume pressure fluctuations. This dual-filler configuration reduces back volume effects on sound quality without increasing the physical size of the speaker.

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Speaker design with multiple nested Helmholtz resonators to improve frequency response and fluid resistance in compact devices. The speaker has a front volume bounded by a housing wall and a frame. Nested resonator chambers are formed by recesses in the frame and separate from the back volume. A first resonator chamber has an entry port in the housing wall. A second resonator chamber is inside the first chamber and has its own entry port. This allows independent frequency response optimization for each resonator.

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Speaker design with a vented resonator to improve high-frequency response in compact electronic devices. The speaker has a front volume, back volume, diaphragm separating them, and a vented resonator between them. The resonator has a port to the front volume, a chamber, and a vent between the chamber and back volume. This allows airflow between the volumes through the resonator instead of directly between the front and back volumes. It reduces front volume size and shortens output path length to improve high-frequency response.

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Spatial audio reproduction with head-tracking and binaural room impulse responses (BRIRs) that have built-in reflection patterns. The BRIRs are generated continuously based on the user's head position and a set of head-related impulse responses (HRIRs) representing acoustic reflections. This allows spatialized sound with customizable reverberation characteristics that follow the user's head movements. The BRIRs approximate the room reverberation by simulating reflections with directions, delays, and equalization to match the actual room's acoustics.

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Vented acoustic transducers like microphones and speakers that equalize barometric pressure across the diaphragm to prevent damage from large pressure swings. The vents have complex acoustic impedance to equalize low-frequency pressure variations while inhibiting higher-frequency pressure variations that can excite the diaphragm. The vents are high-aspect-ratio, elongated channels with tortuous paths through the device. They can also be segmented with acoustic mass and compliance sections. These vents provide equalization without leakage noise.

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Speaker design with improved reliability and sensing capability by using stretchable conductive biphasic materials in the suspension to electrically connect the voice coil to the terminals instead of lead wires. The biphasic material has a solid component like gold-gallium alloy and a liquid component like gallium deposits. This allows the voice coil to move without breaking the electrical connection. The biphasic material can also have strain sensors embedded to detect diaphragm displacement.

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Mitigating loudspeaker-induced acoustic noise in audio devices like laptops to improve overall sound quality by reducing audible noise only when it exceeds the desired sound level. The method involves analyzing the audio signal using a device model to predict the noise level at the listener's position. If the predicted noise exceeds the desired sound level, the device reduces the loudspeaker volume to lower the noise without impacting the desired sound.

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