RM052 is real; the retail feature list is not

The FCC application is dated August 10. Records identify the device as a wireless headphone and include testing around 2.4GHz as well as frequencies in the 5GHz range.

A diagram in the submitted material reportedly carries the Sonos Ace Ultra name. That is meaningful evidence for the branding, but it is not the same thing as a Sonos product announcement. The company has not published an Ace Ultra product page, price or launch specification.

Separate leaked marketing images show something much closer to a revision of the original Ace than a complete visual redesign. The earcups look deeper, microphone openings have changed, and a new sliding control appears on the right side. Its function is still unknown.

The original Sonos Ace already uses Wi-Fi

This is the part that makes the FCC radio testing easy to overread. Sonos' existing Ace already contains 802.11 Wi-Fi capability.

On the current model, Sonos says Wi-Fi is used when the headphones connect to a compatible Sonos home-theater player. That link carries audio and control data for features such as TV Audio Swap. Normal playback from a phone or computer remains Bluetooth-based.

RM052 being tested on 2.4GHz and 5GHz therefore leaves several possibilities open. Sonos could expand its home-theater connection, allow a deeper system handoff, add independent network streaming, or retain a narrower implementation. FCC certification is not a user manual.

The leaked specification sheet goes much further

Reporting based on a separate Dealabs leak claims up to 35 hours of battery life with ANC enabled, compared with the current Ace's official 30-hour figure. It also points to stronger noise cancellation, replaceable ear pads and battery hardware, and a €449 European price.

Those details are not established by the regulatory filing. Neither are the reported September 1 announcement and later September retail dates.

Even the color picture is slightly messy at this stage. FCC-related reporting lists Greige, Shadow Black, Agave, Blush and Sand, while the leaked product renders seen so far focus mainly on black and white hardware.

September itself is confirmed

During Sonos' July 29 fiscal third-quarter earnings call, CEO Tom Conrad said the company would hold a product launch event in September. He described it as the first public look at some of the product work completed over the previous year.

He did not say that the event was for Ace Ultra. Other unreleased Sonos hardware has surfaced in regulatory records since then, so the event and RM052 should not be treated as a formally confirmed pairing yet.

For now, the firm facts are narrower: Sonos has certified a new wireless headphone designated RM052, its radio testing includes 2.4GHz and 5GHz operation, and the company has a product event coming in September.