xMEMS brings speakers plus programmable vent to production

New Products | April 18, 2023

By Peter Clarke

sensors Analog Wearables Sensing / Conditioning

MEMS-based microspeaker developer xMEMS Labs Inc. has announced the general availability of two microspeakers – Cowell and Montara-Plus – and of its dynamic aperature called Skyline DynamicVent.

The microspeakers and vent are optimized for different use cases within true wireless (TWS) earphones, in-ear-monitors (IEMs), digital hearing aids, and other emerging personal audio electronics, including smart glasses and sleep buds.

The Cowell was introduced in November 21 (see MEMS microspeaker for wearables weighs 56mg), the Montara Plus in January 22 (see MEMS microspeaker integrates active venting) and the Skyline is a novel design.

xMEMS’ makes use of silicon-based MEMS both as the driver and diaphragm for moving air at audio frequencies. “Unlike conventional coil speakers, our speakers are monolithic, with silicon membranes offering far better material stiffness and exponentially faster impulse response than conventional speakers, resulting in the superior sound performance of xMEMS Solid-State Fidelity technologies,” said Mike Housholder, vice president of marketing and business development at xMEMS, in a statement.

Small and powerful

Cowell is the world’s smallest solid-state micro speaker, delivering superior high-frequency response and clarity, plus a wider sound stage, for TWS earphones and hearing aids.

Montara Plus, the world’s highest output MEMS micro speaker, is capable of sound pressure levels up to 120dB at 200Hz making it suitable as a full-bandwidth transducer for audiophile, high-resolution in-ear monitors, creating a path to smaller, lighter, simpler IEM designs without the phase-alignment and design complexities of multi-driver IEM implementations.

Skyline DynamicVent is the world’s first piezoMEMS, DSP-controllable vent blends the benefits of open- and closed-fit earbuds and hearing aids. Skyline ushers in a new era of active ambient control (AAC), offering enhanced adaptive automatic noise cancelling and transparency mode implementations with reduced occlusion effects, eliminating the uncomfortable amplification of one’s own voice or footsteps when their ears are covered.

The Skyline DynamicVent, which is separate from the MEMS speaker allows earbud designers to place an opening where they prefer but control it from a DSP or the control ASIC of the MEMS speaker.

The vent closed eliminates low-freqency roll off and produces the best bass response and superior passive isolation. The DSSP can control the vent in response to user input or sensor fusion of microphone, accelerometer, pressure/altitude proximity. With the vent open there is adjustable attenuation, ambient noise is admitted for spatial awareness, reduced occusion effects and less through-body hearing of self-voice and footsteps. It also provides ear pressure relief.

Gaining acceptance

MEMS speakers are now following a similar path to MEMS microphones. MEMS microphone accounted for 5 percent of the market in 2007 and had taken 80 percent by 2022.

“The market for MEMS micro speakers is expected to follow a similar trajectory to MEMS microphones,” said Peter Cooney, founder of analyst company SAR Insight.“Consumer demand for high-resolution, spatial, lossless streaming audio represents a generational shift in audio content that requires a similar evolution in sound reproduction. Solid-state fidelity is able to create a more accurate reproduction of the source audio and a vastly superior listening experience.”

This is accomplished using thin-film piezo technology as the speaker actuator, replacing the coil and magnet, which when combined with silicon as the speaker diaphragm instead of plastic or paper creates the world’s first solid-state speaker.

“Solid-state fidelity and a monolithic architecture not only provide the best listening experience, they also create the most robust speakers in the industry,” Housholder continued.