By: Mike Housholder, xMEMS Labs, Inc.
2 Defining Phase Characteristics of xMEMS’ MEMS Speakers
From customers to journalists, from engineers to audiophiles, everyone is left astounded by the unrivaled audio quality delivered by xMEMS’ patented all silicon MEMS speakers. While they readily acknowledge the superior audio experience delivered by our MEMS micro speakers, many of them seek deeper insights into the underlying factors that contribute to this remarkable acoustic performance.
In this blog post series, we delve into the reasons why xMEMS’ true MEMS speakers offer exceptional audio quality and uncover the distinct advantages of our MEMS micro speakers over voice-coil speaker technologies, including dynamic drivers and balanced armature drivers.
Exploring 2 Key Phase Characteristics xMEMS’ Solid-State Speakers
Have you ever listened to one of your favorite tracks and noticed distorted sound, especially during the striking beginning and gradual fading of sustained musical notes? These distortions can be attributed to random phase response shifts from the speaker.
Traditional dynamic drive coil speakers often suffer from these types of phase shifts, especially at or near their resonant frequencies, leading to distorted sound reproduction. In this month’s blog post, we will delve into why these shifts occur, how they can affect sound quality and what xMEMS solid-state speakers offer to eliminate any non-linear effects, resulting in enhanced audio clarity and precision.
Achieving Near-Zero Phase Shift with a Strategic Design Choice
Phase characteristics play a crucial role in delivering high-quality audio reproduction. Traditional dynamic drive coil speakers often experience a significant phase shift, typically 180°, at or near their resonant frequency, which falls within the human-sensitive audio frequencies (500Hz-2kHz) that might lead to distortions during playback. It is important to avoid such nonlinear phase characteristics in order to ensure optimal sound quality in audio performance.
Figure 1: Calculated impulse response of xMEMS speaker vs. typical TWS dynamic drive speaker; derived from the measured stimulus response on a Klippel Analyzer 3 (KA3) system.
One of the standout features of xMEMS solid-state speakers is their ability to achieve near-zero shift in phase response. Unlike traditional speakers, xMEMS takes an innovative approach to address this issue by placing the resonant frequency well outside the critical audio frequencies, specifically above 10kHz. This deliberate design decision enables xMEMS speakers to deliver a flat, near-zero phase response, with only a minimal deviation of 2°. Consequently, non-linear effects in the sound are effectively suppressed, resulting in enhanced audio fidelity.
Brian Lucey, Mastering Engineer of 9 Grammy Award winners, is captivated by the exceptional phase accuracy delivered by xMEMS speakers. In a recent interview with IEEE Spectrum, he stated, “It’s a huge, huge leap in phase accuracy that we’ve never heard before… Everything is hitting you at the same time. There’s no time smear in the way the sound comes across.[1]”
Leveraging Semiconductor Precision for Part-to-Part Phase Consistency
Produced by Taiwan Semiconductor Manufacturing Co. (TSMC), xMEMS’ patented piezo-MEMS micro speaker technology leverages the precision and uniformity of modern semiconductor fabrication offering another distinct advantage in terms of phase characteristics. Each xMEMS speaker demonstrates an impressive part-to-part phase consistency of +/-1°. This remarkable uniformity has several benefits, including minimizing the need for calibration, eliminating the matching of left and right speakers, and reducing test time and cost. With negligible speaker-to-speaker variation, the audio response remains consistently clear and precise, resulting in enhanced spatial resolution and accuracy for spatial audio applications.
An Ideal Fit for Ultra-High-Resolution Audio Reproduction across Applications
The phase characteristics offered by xMEMS’ solid-state speakers pave the way for significant advancements in audio technology presenting numerous advantages for a wide range of audio applications. Their near-zero phase shift and exceptional phase consistency make them an ideal fit for ultra-high-resolution audio reproduction, immersive virtual reality experiences, personal audio devices such as True Wireless Stereo (TWS), in-ear-monitor (IEM), smart glasses, hearing aids, and more.
In applications where spatial audio plays a pivotal role, the phase consistency of xMEMS micro speakers becomes even more crucial. As audio moves from the left speaker to the right speaker and vice versa, the absence of speaker-to-speaker variation enhances accuracy and spatial resolution and prevents muddiness. The result is a highly precise and immersive soundstage with clear separation and improved audio clarity. With xMEMS speakers, listeners can truly immerse themselves in a rich, lifelike audio environment.
xMEMS’ solid-state speakers revolutionize the audio industry by delivering near-zero phase shift and exceptional phase consistency. With these advancements, xMEMS speakers offer uncompromised sound quality, eliminating distortions and providing precise spatial resolution. As the demand for immersive, ultra-high-resolution audio experiences continues to grow, xMEMS speakers stand at the forefront of audio technology, enabling original equipment manufacturers (OEMs) to design and deliver consumer audio experiences that set new standards for audio fidelity across a wide range of applications.
About xMEMS
Founded in January 2018, xMEMS Labs is reinventing sound with the world’s first solid-state True MEMS speakers for TWS and other personal audio devices. xMEMS has over 100 granted patents worldwide for its technology. The innovative, monolithic transduction architecture implements both actuation and diaphragm in silicon producing the world’s fastest and most precise micro speakers, eliminating spring and suspension recovery of coil speakers. This results in the most accurate time domain music reproduction, unmatched sound clarity, and an elevated sense of space. Please contact us to learn more.