Speaker technology is often misunderstood, with many long-held beliefs rooted in the limitations of traditional designs. As new innovations emerge, it’s time to revisit these myths with a critical eye — backed by physics, engineering, and real-world applications.
1. For powerful bass, you need a large speaker.
Not anymore. While larger diaphragms have historically been associated with deeper bass, modulated ultrasound, a recent breakthrough in sound generation, challenges this assumption.
Modulated ultrasound allows small speakers to generate low frequencies efficiently by using the “pump effect” where the size of a membrane is replaced with the speed of an ultrasonic pump. Realized in microelectromechanical systems (MEMS), modulated ultrasound achieves wide bandwidths without bulky components, proving that novel approaches to sound generation and clever signal processing defy conventional size constraints. The result? Deep bass from drivers 10X smaller than conventional units.
2. One speaker can’t provide both powerful bass and sharp treble.
Modulated ultrasound alters the fundamental physics of sound generation.
Unlike voice coils, which rely on the mechanical and electrical resonances, modulated ultrasound “pump speakers” deliver constant airflow across all audio frequencies from a few Hz to tens of kHz. This approach simplifies acoustic design by eliminating the need for multiple driver configurations, electronic crossovers, and mechanical constraints. A single, compact driver with straightforward acoustic design is all that’s required.
3. MEMS is for microphones, not speakers.
MEMS microphones revolutionized audio capture by replacing electret condensers in smartphones. For many years, achieving the same breakthrough with speakers remained out of reach — until the introduction of modulated ultrasound. This innovation now extends the scalable trajectory of MEMS technology from microphones to speakers.
By leveraging precise, batch-produced actuators with low distortion, MEMS fabrication delivers consistent performance. Built on the same proven material base and electrostatic actuation methods used in MEMS microphones, modulated ultrasound introduces a novel acoustic driver that paves the way for mass production with semiconductor precision.
The industry’s trajectory is clear: Silicon wins when it comes to scalability.
4. MEMS speakers are just tweeters.
The first generation of MEMS speakers tried to implement sound generation by moving MEMS membranes. This resulted in limited performance as these speakers could only provide high-frequency “tweeter” functionality. Modulated ultrasound changes the paradigm of sound generation, enabling full range MEMS speakers. This provides deep bass, crystal clear trebles, and even ultrasound in a much smaller driver.
5. Speakers and microphones must be isolated due to vibrations.
Traditional moving-coil drivers generate mechanical vibrations, creating crosstalk and noise in microphones and other sensors. This limits the ability to combine speakers with other sensors having a negative effect on size and latency.
Modulated ultrasound has no mechanical vibrations at audio frequencies since all movement is at ultrasound. As a result, there’s no mechanical crosstalk, and integrated solutions that include speakers, microphones, bone conduction microphones, and motion sensors can be combined in the same package.
In active noise control (ANC) earbuds, for example, co-locating the speaker and microphone reduces latency and enhances the ANC performance and bandwidth.
6. Small membranes can’t move enough air.
Air displacement depends on diaphragm area excursion. Modulated ultrasound introduces a new variable: cycles per second. This opens a new trajectory for size reduction.
While smaller membranes move less air per cycle, modulated ultrasound compensates with higher speeds (ultrasonic frequencies). Acting as “air pumps,” these speakers use ultrasonic vibrations and rapid oscillations to move and achieve equivalent SPLs with far smaller displacements and diaphragm size.
The breakthrough lies in replacing size with speed when generating airflow. It’s the velocity of movement, not the volume of the membrane, which determines the output.
7. Speaker innovation is only incremental.
For more than 150 years, speaker physics has relied on a membrane generating air flow. While advances in in materials, structures, acoustic design, and electronics have enabled better sound and more compact systems, progress has largely been incremental.
Modulated ultrasound represents a step change in audio technology. “Pump speakers” make possible entirely new acoustic designs and even new products using scalable semiconductor-based manufacturing. The shift toward silicon-based audio components mirrors the semiconductor industry’s disruption of legacy technologies across countless fields
8. Consumers won’t notice the difference in size or sound quality.
Ear canal anatomy varies significantly between individuals (and between ears). This anatomical difference can impact both comfort and acoustic performance.
Smaller drivers open the door to sleeker form factors and entirely new product categories, such as augmented-reality (AR) glasses with embedded audio. But miniaturization isn't just about shrinking hardware; it demands precise ergonomic design and acoustic tuning to ensure consistent performance across diverse users. Modulated ultrasound offers the flexibility to meet these demands, enabling innovation without compromising fit or fidelity.
9. Speakers are fragile and sensitive.
While moving-coil drivers suffer from wear and tear, silicon-based MEMS speakers using modulated ultrasound are highly robust. From materials to architecture, modulated ultrasound speakers follow the trajectory of silicon solid-state devices, offering inherent mechanical robustness, reliability, consistency, and scalability.
10. Tuning ANC is challenging because of the speaker’s resonances.
ANC relies on phase alignment and low latency to effectively cancel noise. Traditional drivers introduce latency and inherent phase shifts due to mechanical resonances, limiting performance.
In contrast, modulated ultrasound speakers have an intrinsic flat phase response, short latency, and high consistency. This simplifies ANC tuning and improves performance across a broader frequency range.
11. You need multiple drivers and complex crossovers for high-quality audio.
Traditional speaker systems rely on multiple specialized drivers — woofers for bass, mid-range for vocals, and tweeters for highs — connected through complex electronic crossovers that introduce phase shifts, power losses, and potential points of failure. This multi-driver approach has been the industry standard for achieving full-range audio reproduction.
Modulated ultrasound eliminates this complexity. Since pump speakers maintain consistent airflow and flat phase response across the entire audio spectrum, a single driver can deliver the full frequency range without the need for crossovers or driver matching. This not only reduces component count and cost but also eliminates the phase-coherence issues that plague multi-driver systems.
The result is simpler acoustic design, improved reliability, and more consistent sound reproduction — all from a single, compact driver that would fit easily in spaces where traditional multi-driver systems simply cannot.
Conclusion: The Audio Revolution
The audio industry is undergoing a quiet revolution. Advances in materials science and miniaturization are challenging long-held assumptions. While no single solution has all of the answers, the direction is clear: Smaller, smarter, and more integrated designs are outpacing legal hardware in both form and function.
