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Plasmacoustics

The Challenge

Compact Solutions for Reducing Low-Frequency Noise Remain Elusive

Conventional passive noise control is effective for high-frequency noise above 1kHz but requires large, heavy materials. This makes it impractical for compact, weight-sensitive applications like vehicle interiors and household appliances.

Active Noise Cancellation (ANC) can reduce low-frequency noise effectively but is complex to implement and difficult to scale. ANC provides only localized noise reduction, limiting its ability to suppress noise across larger areas.

No compact, subwavelength solution currently exists to address noise below 1 kHz in a lightweight form factor.

This presents a market challenge, as low-frequency noise is abrasive and fatiguing, with no practical, scalable solution available to date.

Siless Liner Sound Insulation
Butyl Sound Dampening for Automotive
Movement of the plasmacoustic metalayer under modulating control voltage

Core Enabler

Our unique technology for active sound control relies on the patented concept of the plasmacoustic metalayer.

This is formed by generating a local corona discharge in air or a selected gas suspension (typically a noble gas mixture) between two electrodes spaced no more than 3-5 mm apart.

The high-voltage (HV) electrode features an array of thin, evenly spaced tungsten wires, while the collector electrode is typically a plate of conducting material.

Upon application of a constant high voltage, the air or chosen gas near the HV electrode ionizes, creating positive ions.

A second modulating voltage is then applied across the same set of electrodes to control the movement of the ions.

This invisible, massless layer of charged gas immediately interacts with the surrounding air to produce sound, achieving a broadband frequency response without any undesirable phase shift relative to its electrical input.

Response of disabled Plasmapanel to an incident sound wave Response of enabled Plasmapanel to the same incident sound wave

The Solution

Plasmapanel® - Active Sound Control

Plasmapanel technology utilises the Plasmacoustic Metalayer to achieve efficient sound absorption through active control. A microphone positioned in front of the panel measures incoming sound and sends the signal to a controller for processing.

The controller generates a response that modulates the movement of the metalayer, adjusting the acoustic impedance across the panel’s surface to maximize sound absorption and minimize reflections.

Plasmapanel functions as a deep subwavelength absorber, reducing sound effectively across a wide frequency range, from just a few Hz to several kHz.

Its slim profile (less than 3 cm) and lightweight design (under 1.5 kg/mÇ) make it ideal for noise reduction in many applications.

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About us

Sonexos is a Swiss-based engineering company specialising in advanced audio and sound technologies. We develop innovative solutions in audio enhancement and active sound control, supplying these to global customers in the automotive, consumer, mass transportation, and industrial sectors.

One of our standout innovations is the Plasmapanel, a technology that applies advanced active sound absorption to reduce noise in enclosed spaces like vehicle cabins, offices, rooms, machinery, and ducts. By addressing noise at its source, Plasmapanel creates quieter, more comfortable environments across various industries.

 

In addition to our focus on research and development, Sonexos offers strategic counsel to help clients innovate in audio and sound. Our advisory services include product development, benchmarking, and manufacturing support, ensuring clients successfully implement advanced technologies and strengthen their market position.

By delivering cutting-edge sound solutions and expert guidance, Sonexos enables businesses to thrive in a competitive landscape. Where sound enhances experience, Sonexos delivers.