Sonos FCC Filing Reveals "Ace Ultra" Headphones with Built-In Wi-Fi

An FCC filing by Sonos for model number S52A has surfaced, revealing details about an upcoming pair of wireless headphones expected to succeed the Sonos Ace this fall. The filing, published by the US Federal Communications Commission and first reported by Lowpass, has been independently reviewed by Lowpass, What Hi-Fi?, and other outlets. It is heavily redacted, but several product specifics remain visible in the submitted documents.
One document shows an oval diagram, likely the ear cup, marked with the name "Sonos Ace Ultra." That name does not appear elsewhere in the filing. The device is officially identified only as model S52A throughout the remaining paperwork. The filing lists five color options: greige, shadow black, agave, blush, and sand.
The filing indicates radio testing for local networks over the 2.4 GHz and 5 GHz bands, the two frequency ranges most home Wi-Fi networks use. That points to on-device Wi-Fi capability rather than Bluetooth-only operation. This aligns with reporting from Tech Times, which notes that the filing suggests the headphones will feature more powerful Wi-Fi and full Sonos ecosystem integration. For a company whose speaker business is built on whole-home audio over Wi-Fi, bringing that same connectivity to headphones would set the product apart in a category where most devices rely on Bluetooth alone.
Sonos CEO Tom Conrad hinted at a successor to the Sonos Ace during the company's third-quarter earnings call, though the filing itself provides no pricing or release date. What Hi-Fi? reports that the filing suggests a launch next month, and multiple outlets place the expected announcement at a September 2026 event.
The original Sonos Ace headphones are listed on Sonos's own website as the "Ace 4.6" premium noise-canceling headphones at $299. The Ace line was released over two years ago, making this the first refresh of the product family. The current Ace connects via Bluetooth and USB-C with Sonos ecosystem features, but the S52A filing's 2.4/5 GHz testing suggests the successor could communicate directly with Sonos speakers over local Wi-Fi rather than relying on a phone as a go-between. The filing does not specify which protocols or audio codecs would be used over those bands.
The color palette itself is worth noting. Greige and shadow black carry over from the current Ace lineup. Agave, blush, and sand are new additions, suggesting Sonos is broadening the aesthetic range of the product rather than simply updating the internals. Whether those translate to different finish materials or are purely color variations is not clear from the filing.
The redactions in the S52A filing are extensive enough that key specifications remain unknown. There is no confirmed information on driver size, battery life, active noise cancellation implementation, codec support, or whether a voice assistant is embedded. Lowpass's original reporting on the filing hints at a voice assistant feature, but the redacted documents themselves do not confirm this. What is visible is limited to the model number, the Wi-Fi band testing, the color options, and the "Ace Ultra" labeling on a single diagram.
For context, Sonos entered the headphone market with the Ace as its first non-speaker product. The move was watched closely because it tested whether Sonos could extend its multi-room audio ecosystem into a wearable form factor. A second-generation device with native Wi-Fi would build on that thesis, potentially allowing the headphones to participate in Sonos's whole-home audio mesh directly, switching sources, grouping with speakers, or streaming without phone tethering.
The broader context here is whether Sonos can compete in a headphone category where margins are thin and incumbents are firmly established. Adding Wi-Fi and deeper ecosystem integration is a plausible way to stand out, but it also adds complexity in battery management, firmware, and interoperability. The September event should clarify how much of the S52A's Wi-Fi capability is shipping-ready versus aspirational.


