Optimizing Sound Quality in MacBook Speaker Design
44 patents in this list
Updated:
In modern MacBooks, speaker systems must deliver high-quality audio within severe space and power constraints. Current designs operate within enclosure volumes under 100cm³, yet must reproduce frequencies from 60Hz to 20kHz while maintaining clarity at sound pressure levels above 85dB. The challenge is compounded by varying acoustic conditions as users move devices between different environments and orientations.
The fundamental engineering trade-off lies in balancing acoustic performance against the physical limitations of thin device profiles and thermal management requirements.
This page brings together solutions from recent research—including adaptive resonance control systems, moving magnet motor designs, real-time environment sensing, and pressure-management mechanisms. These and other approaches focus on maximizing audio quality while working within the strict dimensional and power constraints of mobile computing devices.
1. Audio System with Real-Time Resonant Frequency Detection for Speaker Output Control
Apple Inc., 2023
Adaptive resonance-controlled audio systems and methods for speakers in compact electronic devices to enhance loudness. The method involves determining the resonant frequencies of the speaker in real time based on measured electrical characteristics of the speaker component. The audio output is then generated at the determined resonant frequencies to provide loudness optimization. This ensures the audio is output at the speaker's resonant peaks rather than off-peak frequencies.
2. Speaker Occlusion Ejection via Real-Time Resonant Frequency Adaptation
Apple Inc., 2023
Adaptive resonance-based occlusion ejection for audio components like speakers in electronic devices. The technique involves determining the resonant frequency of the speaker based on electrical characteristics while it's occluded. Then, the speaker is operated at that resonant frequency to eject the occlusion. This is done in real-time as the speaker is occluded by water or debris to enhance loudness by optimizing output frequencies.
3. Hierarchical Spatial Encoding System for Adaptive Bitrate Adjustment of Immersive Audio Content
Apple Inc., 2023
Adaptive encoding of immersive audio content to reduce bandwidth requirements while maintaining quality as the target bitrate changes. The encoding involves adaptively adjusting the representation of the immersive audio scenes based on priority analysis and target bitrate. It converts lower priority channels, objects, and higher order ambisonics (HOA) into lower quality forms like stereo or compressed HOA to save bandwidth. This allows representing scenes with varying combinations of quality levels and bitrates based on target needs. The encoding involves a hierarchy of spatial encoders that adaptively generate bitstreams of different content types as the target bitrate changes.
4. Moving Magnet Motor with Flux Concentrator for Loudspeakers
Apple Inc., 2023
Moving magnet motor for loudspeakers that reduces distortion and enables larger excursion compared to conventional moving magnet speakers. The motor has a closed magnetic circuit with a magnet and flux concentrator near the coil. The magnet and concentrator move together over the coil, focusing the magnetic flux density on the coil. This concentrates the flux density over the coil instead of passing through it, reducing reverse flux effects. This allows larger excursions without cancellation from opposite polarity flux. The concentrator follows the magnet's motion.
5. Foldable Electronic Device with Flexible Voice Coil and Textile Sound Emission Layers
Apple Inc., 2023
Flexible electronic devices with foldable voice coil layers and outer textile layers that emit sound. The devices have flexible components like voice coils and textile layers that can be folded and expanded for portability while maintaining functionality. This allows the devices to be compact and foldable for easier carrying and storage. The foldable design improves portability without compromising the device's audio output capability.
6. Transducer with Integrated Dual-Function Magnet Motor Assembly for Electroacoustic and Tactile Applications
Apple Inc., 2023
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.
7. Audio Output Adjustment System with User Position and Environment-Based Sensor Integration
Apple Inc., 2023
Adjusting audio output of electronic devices to improve audio quality based on user location, orientation, and environment. The system uses sensors to detect user position relative to the device, gather environmental data, and dynamically adjust audio settings like volume, equalization, and spatialization without user input. This enhances audio output for scenarios like video conferencing with multiple participants at different distances, where the system can adapt the audio to better match user positions and orientations.
8. Impulse Pressure Rejecting Valve with Flow Resistive Mesh for Speaker Diaphragm Protection in Portable Electronic Devices
Apple Inc., 2023
Impulse pressure rejecting valve for portable electronic devices like smartphones that prevents excessive speaker diaphragm excursion when a user interacts with the device. The valve allows communication between the speaker's back volume chamber and the device's interior chamber while also closing off the connection when a pressure event occurs from user interaction. This prevents the pressure from affecting the speaker's output. The valve has a flow resistive mesh to allow equalization but closes for impulse pressures.
9. Dual-Speaker Headphones with Directional Sound Output and Phase-Controlled Privacy Mode
Apple Inc., 2023
Dual-speaker headphones that provide audio privacy by outputting sound in different directions. The headphones have two speakers integrated into the housing. In a private mode, the speakers are driven with signals that are out of phase with each other, canceling the sound at some angles. In a public mode, the speakers are driven in phase. This allows the user to hear audio while suppressing sound for nearby listeners. The mode is detected based on distance or microphone input.
10. Microphone Enclosure with Damping Material and Separate Resonators for Resonance Mitigation
Apple Inc., 2023
Improving microphone performance in compact electronic devices like smartphones and wearables by mitigating resonance effects from enclosure cavities. The techniques involve adding damping material around the microphone, preventing cavity closure, and introducing separate resonators. This reduces acoustic resonances in the enclosure that can disrupt microphone input at certain frequencies. The damping prevents cavity resonance, separate resonators counteract it, and avoiding cavity closure stops it.
11. Audio Synchronization System for Portable Devices Using Remote Speakers with Timing and Directional Adjustments
Apple Inc., 2023
Audio integration of portable electronic devices in enclosed environments like vehicles or rooms to create a psychoacoustic perception that center audio content like dialog is anchored to the device location even when the audio is played through remote speakers. The integration involves timing adjustments and speaker directionality to match the audio output between the device speaker and remote speaker. When a device shows video inside an enclosure, it sends the audio to the enclosure's speakers. The enclosure speakers generate the audio and the device speaker delays its output. This aligns the audio timing for the viewer's perception. The enclosure speakers can also steer the audio to match the device's location.
12. Multi-Driver Speaker System with Coordinated Cross-Channel Gain Reduction Mechanism
Apple Inc., 2023
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.
13. Integrated Speaker Module with Moving Coil Woofer and Piezoelectric Tweeter
Apple Inc., 2023
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.
14. Internal Speaker Enclosure with Rib-Supported Thin Walls and Opposing Phase Drivers
Apple Inc., 2023
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.
15. Hinged Cable Routing System with Debris Relief Channels and Flexible Barriers
Apple Inc., 2023
Cable routing through hinged sections of electronic devices to protect the cables from damage and particles during device movement. The cables are bendable over curved surfaces of hinges to allow movement. Features like debris relief channels, flexible barriers, and compressible covers prevent particles from lodging between the cable and curved surface and apply minimal pressure. This prevents particle-induced cable damage and failure. The covers also guide the cables during hinge movement.
16. Silicone Elastomers with Alicyclic Alkane Side Groups on Siloxane Backbone
Apple Inc., 2023
Silicone elastomers with high damping properties for applications like speaker components and noise damping. The damping is tuned by modifying the side groups on the siloxane backbone. The side groups are alicyclic alkanes like bicyclo[3.1.0]hexyl or norbornyl. These side groups provide higher damping than standard fillers like carbon black. The modified siloxanes can be synthesized and used to make cured silicone rubbers with defined maximum damping points in the frequency range 0.5-30000 Hz at temperatures 0-50° C.
17. Audio Signal Processing System with Sub-Band Spatialization for Enhanced Sound Localization
Apple Inc., 2023
Spatializing sound to create a more realistic listening experience by splitting an audio signal representing the sound of an object into sub-bands and assigning them to different locations within the visual representation of the object. This allows reproducing the sound as if coming from different places in the visual element, enhancing spatial perception. Multiple sub-bands are generated for different locations within the object's visual representation, and combined with speaker driver signals to produce the spatialized sound.
18. Portable Electronic Device Components with Recessed Display Stack, Pouch-Enclosed Battery, and Compact Haptic Actuator
APPLE INC., 2023
Compacting the size of components like displays, batteries, and haptic actuators in portable electronic devices like smartphones without sacrificing functionality. Techniques for reducing component size include: - Display: A top module with a recessed display stack and a frame that gaps from the housing recess. This allows a thinner overall display size without compromising touch and viewing. - Battery: Enclosing the battery components in a pouch with a metal foil layer. This reduces the risk of internal shorting when the battery contacts the device housing. - Haptic actuator: A housing with recesses to hold the springs and mass. This allows a smaller actuator size while maintaining effectiveness. These techniques provide space savings for components that can help reduce the overall size of portable electronic devices.
19. Planar Magnetic Speaker Driver with Peripheral Conductive Traces and Central Diaphragm Clearance
APPLE INC., 2023
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.
20. Sub-Wavelength Ultrasonic Attenuator Array with Asymmetric Stairway-Patterned Micro Helmholtz Resonators
Apple Inc., 2023
Array of sub-wavelength attenuators to absorb ultrasonic acoustic waves and suppress subharmonics in electronic devices like earphones and smartphones. The attenuators are micro-sized Helmholtz resonators arranged in an asymmetric stairway pattern along the acoustic path between the transducer and port. The attenuators absorb ultrasonics by volume and length dimensions tailored to specific frequencies. The stairway pattern maximizes absorption with smaller features compared to wavelength. The attenuators can be formed within the substrate or attached as an insert. The stairway pattern enables capture of sound energy with much smaller features compared to the wavelength.
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