Next-gen MEMS ultrasonic solid-state earbud drivers will deliver the bass

While MEMS drivers may be the next big thing in true wireless earbuds, the first models with the solid-state components still require a hybrid setup. These products pair a MEMS speaker with a dynamic driver to ensure proper bass performance. The current-gen driver from xMEMS, a California-based company that develops the audio components, is called Cowell and it's already available in earbuds from the likes of Creative and Noble Audio.

The next-gen MEMS driver is called Cypress, and while it won't arrive in new products until 2025, I got a chance to hear the difference been it and Cowell at CES 2024 here in Las Vegas — and it's quite striking. With Cowell, there's bass, but it's subdued and the emphasis is on the highs and the mids. It sounds great, on both complete products and reference designs, offering punchy highs, full mids and great clarity. With Cypress alone though, there's a blanket of warm, bassy low-end that really fills out the soundstage. It will be a massive improvement for what MEMS drivers are capable of doing for wireless earbuds.

"We moved to a sound from ultrasound principle where we have ultrasonic modulation and demodulation to deliver 30 to 40 times greater low-frequency pressure for anti-noise generation for ANC earbuds, while still delivering all of the benefits of our solid state speakers," xMEMS vice president of marketing Mike Housholder explained. "Wide dynamic range, with excellent low-frequency performance for deep bass and noise cancellation."

Indeed, that 30 to 40 times louder bass response was clearly evident when on a Cypress reference design. The prototype was built to showcase the MEMS drivers on their own, without that secondary dynamic driver today's true wireless models require for bass. The results are the pristine clarity you'd expect in a send of high-end wireless headphones or even some audiophile-grade cans. The additional bass isn't loud and boomy, but instead it's warm and full, inviting you to stay and listen a while. And that I did: I had a hard time putting the Cypress prototype down even when I felt I'd overstayed my welcome.

On the whole, MEMS drivers offer a host of benefits over coil speakers that should all lead to better audio quality in your earbuds. They're more efficient in terms of mechanical response, with faster speeds there contributing to increased detail and clarity — something I certainly noticed on the Noble Audio FoKus Triumph wireless earbuds. This model pairs Cowell with a 6.5mm dynamic driver, but the boost in fidelity in the mids and highs is apparent. And getting a set of earbuds with MEMS drivers doesn't mean you'll pay more. The two models Creative has already debuted are $130 and $150. The same will be true for upcoming products with the ultrasonic Cypress drivers, according to Housholder.

"We see ourselves going to market first in flagship products," he said. "As with our current products, we really see the sweet spot for our products anywhere 150 and up, [which] is easily achievable day one. And then over time and over volume, getting down to that $100 price point."

And that's really the big takeaway from me. For years, companies have offered true wireless earbuds with some of the features of more premium flagship models, but usually lacking the sonic performance of pricier options. With MEMS drivers, the audio quality is greatly improved in affordable models that are half the price of the top-of-the-line Sony or Sennheiser noise-canceling earbuds. And with Cypress, xMEMS can offer audio companies the ability to improve overall sound quality without having to raise prices.

xMEMS has also developed what it calls a DynamicVent to relieve occlusion in sleep earbuds. The component can automatically open or close depending on if the buds detect ambient noise like a snoring spouse. When open, the DynamicVent offers a semi-open fit like AirPods, but when it's closed the ear will be completely sealed off. The open vent should also keep sounds of your own breathing or the earbuds rubbing against a pillow from disturbing your sleep. xMEMS is showing off the DynamicVent at CES in a set of reference sleep buds equipped with its Cowell MEMS drivers.

We're reporting live from CES 2024 in Las Vegas from January 6-12. Keep up with all the latest news from the show here.