TWS earphone with multiple speakers and crossover circuit embedded therein

What is this patent about?

’259 is related to the field of wireless audio devices, specifically True Wireless Stereo (TWS) earphones. It addresses the inherent sound quality limitations of compact, wire-free earbuds which traditionally rely on a single full-range driver that often struggles to reproduce a broad and accurate frequency response.

The underlying idea behind ’259 is the integration of a multi-driver acoustic architecture and a dedicated passive crossover network directly within the constrained housing of a TWS earbud. By splitting the wireless audio signal into distinct frequency bands before they reach the transducers, the system allows specialized drivers to handle the specific ranges they are best suited for, such as using a larger diaphragm for bass and a smaller, stiffer one for treble.

The claims of ’259 focus on a specific circuit topology for the internal frequency division that utilizes a network of resistors and at least one capacitor to route signals. The independent claims define two primary configurations: one employing at least two dynamic speakers with different response characteristics, and another utilizing a hybrid assembly of a dynamic speaker for low-end frequencies paired with one or more balanced armatures for high-frequency precision.

In practice, the invention functions by taking the analog output from a Bluetooth module and passing it through a bridge of resistors and capacitors that act as high-pass and low-pass filters. For instance, a first capacitor is positioned to block low frequencies from reaching the sensitive high-frequency drivers, while a resistive network manages the power attenuation and signal flow to the woofer, ensuring a balanced output across the audible spectrum.

This approach differentiates itself from standard TWS designs by moving away from software-only equalization or single-driver compromises. By implementing a hardware-based crossover circuit to drive multiple specialized units—such as a PET-diaphragm woofer and a beryllium-plated tweeter—the invention achieves high-fidelity separation and clarity that mimics high-end wired monitors while maintaining a fully portable, wireless form factor.