Sonos Ace Ultra spotted in FCC listings...... and leaks, and rumors, and moreUpcoming launch sounds imminent for the second-generation over-earsIt's been two years since the release of the Sonos Ace, the inuagural premium over-ear headphones from the well-known wireless multi-room audio pioneer. And it sounds like a new follow-up pair are on the way... with a linguistic upgrade in stock.We know a Sonos launch event is happening in September, and now, FCC listings point to a new pair of wireless headphones. It doesn't take a genius to put two and two together to deduce that Sonos' second stab at wireless cans are the product cleared for launch?And if that wasn't obvious enough, a pair of headphones called the Sonos Ace Ultra have been leaking left, right and center. Winfuture recently published a suite of pictures and details about them, which ensure (if the images prove genuine, of course) there's very little mystery left to uncover.These images of the headphones look pretty similar to the original Ace, but with bigger ear cups and a slider on the body. In terms of design, then, they still look closer than most to Apple's AirPods Max, albeit with more pill-shaped ear cups.Ultra by name, ultra by nature?By all accounts, then, Sonos has some AirPods Max 2 rivals, ready to drop on us at a moment's notice (or competitors to the Sony WH-1000XM6, Bose QuietComfort Ultra 2nd Gen, Dali IO-8, take your pick from one of the many premium headphones out there).The real question is, what does the 'Ultra' in the name mean? Will these cost even more than the original Ace? Perhaps an advanced multi-driver set-up? Maybe some extra features, as in the Sony 1000X The Collexion? Or, most pertinently here: will they work within Sonos' multi-room ecosystem, for true audio hand-off to and from the grouped Sonos speakers in your home? The original Ace could do this only to your Sonos Arc, via the TV Audio Swap feature, which made many fans disappointed.So far, the leaks don't really explain what's Ultra about these headphones, so that's something Sonos will have to sell us on when the new headphones arrive. TechRadar's Audio Editor Becky Scarrott suggests that anything other than proper audio hand-off to the Sonos wireless speaker array in your home would be a misstep for the company. It's something fans really want — and that rival Bowers & Wilkins has been offering for quite some time in its headphones and earbuds, including the Bowers & Wilkins PX8 and five-star Pi8 earbuds. Both are controlled by B&W's Music app, which enables audio hand-off from your buds/cans to your home system when you walk through the door, to any speaker in Bowers & Wilkins’ own Formation range, including the Formation Wedge and newer Zeppelin Pro. Hopefully, we will see this though; the name suggests that these headphones aren't a sequel to the Sonos Ace (which gained mixed reviews and a four-star review from this publication), but a 'pro' version. And the features will need to match.For now, watch this space…