Speaker on a chip: Making sound from ultrasound with microchips

Nearly all earbuds, headphones, and speakers in large sound systems use a 100-year-old technology built from magnets, coils, and vibrating membranes to produce sound. A five-year-old audio startup is reinventing how speakers are made with microchips, and commercializing a revolutionary new way of producing sound that once seemed almost science fiction: from ultrasound.

“The coil and magnet speaker has been our only means of experiencing sound our entire lives,” Mike Householder, vice president of XMEMS Labs, told me on the TechFirst Podcast. “It was invented in the 1800s, perfected in the 1920s, and gradually improved since then… It rotates a magnet which then pushes through different layers of suspension, a paper or plastic diaphragm which moves air, and produces sound essentially unchanged for a hundred years.”

xMEMS is replacing that traditional speaker technology with a solid state semiconductor: a chip that is in some ways similar to the chips that power our computers.

This is a big deal for manufacturability: You can now make chips like speakers at high volumes, with reproducible uniformity and high rates of quality, resulting in exactly the same balanced, phase-aligned audio every time. It happens. Householder says chip-based speakers also create a better audio experience, as they have much faster response times than traditional speakers with paper or plastic membranes. Under heavy load from a busy soundstage, paper or plastic has a tendency to distort and muddy the audio, while solid-state MEMS (micro-electromechanical system) speakers maintain the perfect shape.

Plus, you can theoretically wash them and there will be no harm (though other electronic parts of your earbuds, headphones, or speakers won’t appreciate the hydrospa treatment).

“Once a solid state version exists, over time, it will take up the majority of unit volume for that function,” says Householder, citing product categories such as hard drives, batteries, fuseboxes, etc.

It also opens up possibilities for speaker printing for myriad other use cases, for example, providing smart machines with ChatGPT API access.

However, there is another important innovation that xMEMS is releasing right now that is important, and it is one that unlocks the ability to have larger speakers for home or perhaps car use with MEMS technology. That innovation is producing human audible sounds from ultrasound.

The company’s new Cypress solid-state MEMS speaker replaces traditional air-pushing speaker technology with what XMEMS calls “ultrasonic amplitude modulation transduction principle.” Essentially, this means that the new speaker generates ultrasound – sound beyond human hearing levels – and then converts it into human audible sound that the company describes as “rich, detailed, bass-heavy, high-fidelity.” The audio says.

Technical explanation shared by the company:

“As an air pulse generator, the Cypress contains: a modulator to generate an amplitude-modulated ultrasonic wave (carrier) that faithfully follows the amplitude of the intended audio signal; and a demodulator to synchronously demodulate the ultrasonic wave, transferring the acoustic energy to the baseband, resulting in the desired audible sound.

Although it sounds like magic, the result is an entirely new way of producing sound that the company says is more faithful to the sound originally created by the musicians, is higher-resolution, and Works better with new audio formats like Spatial Audio.

Importantly, this would theoretically unlock the ability to produce greater volume than a small chip-based speaker, and therefore ultimately expand MEMS-based speakers from small in-ear and over-ear solutions to larger rooms. Filling out the application.

Right now, it is well-adapted to improving active noise cancellation technologies – critical to success in the market for in-ear and over-ear solutions today – with a wider bandwidth of effectiveness for high-frequency noise.

The XMEMS chip-based speaker technology is currently in the market in high-end yearbuds of Singularity Audio (Retail Price: $ 1,500) in the US, as well as a high-end product of a Japanese company ceramic.

This week, the company announced it is adding consumer-value products through a partnership with Creative, an audio card, headphone and speaker company. For example, the Creative Orvana Ace 2 costs $150, which Householder says is “very consumer friendly.”

“As an audio company committed to delivering superior sound experiences, Creative is excited to partner with XMEMS Labs to integrate its innovative MEMS technology into our TWS products,” Creative CEO Song Seo Hui said in a statement. Is.” “By doing so, we are confident that our TWS products will stand out in the marketplace and provide our users with exceptional sound quality, comfort and style.”

However, Cypress noise-cancelling products will not be on the market immediately. The company will showcase these at CES in Las Vegas in January, with a release possibly coming to market sometime in 2024.