Today the US Patent & Trademark Office published a patent application from Apple that relates to audio transducers for electronic devices, particularly the iPad, including for example, speakers with multiple resonators that could deliver superior high-quality audio. The patent is likely aimed at iPads other than the iPad Pro which already delivers an advanced 4-speaker system with support for Dolby Atmos.  

In Apple's patent background they note that challenges could arise when constraints for spatial integration with other device components, liquid resistance, and/or other constraints compete with audio quality constraints when attempting to implement an audio transducer module (e.g., a speaker module, or a speaker) in a device. These challenges could be particularly difficult when attempting to implement an audio transducer module into a compact portable or wearable devices.

To accommodate spatial constraints, a speaker may be provided with an extended path length from the transducer to a sound outlet port. However, such an extended path length could lead to undesired peaks and/or roll off of the middle and/or high frequency range response of the module.

In accordance with various aspects of today's patent filing, a speaker module (speaker) may be provided with multiple resonators (e.g., Helmholtz resonators, or HHRs) each having a corresponding frequency.

For example, a speaker module may include a first resonator that is acoustically coupled to a front volume of the speaker module that addresses (e.g., reduces an undesired frequency response peak in) a mid-band frequency response (e.g., between about 2 kHz and 4 kHz) of the speaker module.

In one or more implementations, the speaker module may also include a second resonator and/or a third resonator that mitigate roll off of the frequency response of the speaker module in a relatively high frequency range (e.g., above about 8 kHz), such as by redistributing and/or attenuating the energy and sound pressure from around 8 kHz to a wider frequency band. In one or more implementations, the speaker module may include first and second resonators that are spatially nested and that have independent entry points on a rear side of the front volume of the speaker module.

] In accordance with various aspects of the subject disclosure, a speaker for an electronic device may be provided, the speaker having a flattened response at high frequencies while maintaining fluid resistance for the device. In one or more implementations, first and second resonators (e.g., Helmholtz resonators) are provided that include respective adjacent ports to a front volume of the speaker. A chamber, and a channel between the port and the chamber, for the first resonator may be at least partially embedded or nested in, and acoustically separate from a chamber of the second resonator. A third resonator may also be provided, which may be adjacent to and/or nested within the first and/or second resonators, or which may be spatially separated from the first and second resonators.

Apple's patent FIG. 1 below illustrates a perspective view of an example electronic device (an iPad) having an audio transducer with multiple resonators; FIG. 2 illustrates a cross-sectional side view of a portion of an example electronic device having an audio transducer module with multiple resonators; and FIG. 4 illustrates a cross-sectional side view of an audio transducer module that includes acoustically separate, spatially nested resonators in accordance with various aspects of the subject technology.

While the patent figures focused on an iPad, Apple states that their invention could apply to other future devices using this technology including an iPhone, AirPods, Apple Watch, MacBooks and other wearables.

For more details, review Apple's patent application number US 20220360886 A1.