In 2024, Sonos launched its latest flagship soundbar, the Sonos Arc Ultra, showcasing a significant advancement in audio technology with the introduction of its new Sound Motion design. This innovative speaker system incorporates more audio drivers than its predecessor while maintaining the same compact size, delivering an enhanced Dolby Atmos experience.
The breakthrough technology behind this achievement is the compact bass speaker design acquired from Mayht in 2022. This acquisition marked a pivotal moment for Sonos, as the Sound Motion technology began its first commercial application in the Arc Ultra. Naphur van Apeldoorn, Senior Manager of Hardware Development Engineering at Sonos, provided insights into the development process and the transformative potential of Sound Motion.
Revolutionizing Sound Production
The Sound Motion system is a game-changer in speaker design. Unlike traditional speaker drivers that rely on a deep cone shape, Sound Motion utilizes a flat, dual-sided configuration that allows it to displace a significant volume of air in a smaller space. Van Apeldoorn elaborated on this innovation, stating that the system consists of four magnetic motors positioned at the corners of the speaker, working in pairs. Each motor connects to its diagonal counterpart via an aluminum rib, enabling the movement of air in a highly efficient manner. He explained, “A bigger portion of the transducer actually pushes air compared to a conventional transducer,” enhancing sound production relative to size.
To illustrate this efficiency, van Apeldoorn noted that the single Sound Motion woofer in the Arc Ultra produces the same output as all eight woofers in the original Arc model. This design allows for powerful bass performance from a compact unit, capable of moving nearly a liter of air, comparable to a conventional 10-inch to 12-inch subwoofer.
Another remarkable feature of the Sound Motion system is its force-cancelling capability. By using two cones that push air in opposite directions while producing the same audio signal, the system effectively cancels out unwanted vibrations, resulting in a clearer audio experience.
Engineering Challenges and Solutions
Van Apeldoorn, who previously worked at Mayht, explained that the transition from prototype to mass production involved significant challenges. “The first question was how to fit a square peg into a round hole,” he recalled, referring to the initial prototype, known as T3, which was larger than the soundbar’s cross-section. The engineering team faced the task of adapting the Sound Motion design to fit within the constraints of the Arc Ultra’s shape.
To achieve this, the team created over 900 digital prototypes, iterating rapidly on the design using simulations and 3D printing. Van Apeldoorn described the process: “During the day, the engineers would run simulations and CAD designs. In the evening, we would put them in the 3D printers; the next morning, the prints would be ready for testing.” This approach allowed for quick modifications without the limitations of traditional manufacturing processes.
Once a suitable design was established, Sonos leveraged its extensive materials library to refine the Sound Motion transducer further. Van Apeldoorn emphasized the importance of material selection, stating that the materials used for the Arc Ultra’s sound components closely resemble those in the Sonos Era 100 and Era 300 speakers. This choice ensured durability under the high air pressure generated by the transducers during operation, necessitating robust reinforcement to maintain structural integrity over time.
Despite initial challenges with air leakage in the first prototype, the team persevered. Van Apeldoorn recalled, “The first prototype we made was leaky everywhere. You could hear the air coming out.” After adjustments and further testing, they successfully created an airtight design that enhanced the overall performance of the speaker.
Future Prospects for Sound Motion
Looking ahead, van Apeldoorn hinted at the potential for Sound Motion technology to be integrated into various product lines. While he did not disclose specific upcoming products, he emphasized the versatility of the technology. The Arc Ultra serves as a foundation for exploring different configurations, including prototypes that experimented with up to ten motors for even greater performance.
When asked about the feasibility of using Sound Motion for larger subwoofers, van Apeldoorn acknowledged the potential for scaling the technology. “There’s definitely some room to scale the technology up there,” he affirmed. He also noted the possibility of using the technology for higher frequencies, though space constraints may limit its application in smaller devices such as laptops and mobile phones.
As Sonos continues to innovate in sound technology, van Apeldoorn highlighted the company’s commitment to enhancing user experiences. “The big question then becomes: what is the next experience we want to deliver to people?” he concluded, reflecting on the evolving landscape of audio content, including the increasing availability of Dolby Atmos material and high-resolution audio.
With the Arc Ultra, Sonos not only demonstrates its engineering prowess but also sets the stage for future advancements in audio technology that could redefine sound quality in home entertainment systems.
