Launching today, Bose's new QuietComfort 35 headphones build on the outstanding active noise cancellation (ANC) tech in its popular wired QC25 and QC15 predecessors, while adding Bluetooth wireless. We've been testing the freshly untethered cans today to see how they compare to the (former?) best-in-class Sennheiser Momentum 2.0 Wireless.

Bose managed to keep the size nice and compact on the QuietComfort 35 – they're only a little bigger than the old QC25s, despite adding Bluetooth.

The QC35 sticks with the same basic design language as its predecessors, which isn't a bad thing in our book. They also feel very comfortable and lightweight – again, not surprising at all given the QC legacy and the fact that one of Bose's biggest target audiences is frequent flyers.

It's too early to comment on battery life, but Bose is quoting 20 hours per charge. And this time around, the headphones have a built-in battery, charging via microUSB, instead of the AAA batteries from its predecessor. While the new approach will save you money, it does have the potential drawback of no longer being able to pop in a new battery and get instant fully-charged gratification. For most people, though, the 20-hour uptimes (assuming they hold up) should cancel that out.

The biggest questions, then, are a) how do they sound? and b) how good is the noise cancellation?

The preconception going in is that Bose headphones have market-leading ANC but audio that, while solid enough, falls short of audiophile level. As someone who doesn't frequently review audio gear, I'm less audiophile, and more someone who's used enough mobile headphones through the years to have a pretty good idea of what's great, what's just good and what's utter rubbish. I also once owned a pair of Bose QC25s and found their audio to trail far behind these Sennheiser Momentums.

Compared to the wireless Momentums (right), the audio of the wireless Bose QC35s holds up surprisingly well. We'd still give the edge to the Sennheisers, but not by nearly as wide a margin as expected – they sound just a smidge better to me. Listening wirelessly to a variety of Tidal lossless tracks with flat EQ, while paired with an HTC 10 (one of the best phones for audio quality) and Galaxy S7 edge, the Momentums had a slightly wider soundstage and perhaps a hair more punch in the bass and nuance in the highs. But it's very, very close – I could listen to either pair on a transcontinental flight and my ears would be extremely happy. If the Sennheiser audio gets an A+, then the Bose audio comes in with a very solid A that's approaching an A+. Not the B or B- that I'd have given previous entries in the Bose QuietComfort series.

The gap in noise cancellation is wider than the gap in audio quality – and if you're familiar with Bose's authority in this space, it won't surprise you that the QC35s come out ahead. I listened to both headphones with a vacuum cleaner running a few feet away (a similar frequency to an airplane engine), both with audio playing and no audio playing, and in both cases the vacuum noise was almost completely snuffed out by the Bose. The noise was still muffled, but much more audible, on the Sennheisers. The difference was just as pronounced swapping out the vacuum cleaner for a TV show playing in the same room.

It's not that the Sennheisers have bad active noise cancelling – it does a good job. It's just that Bose's noise cancelling is second to none, even without wires.

Based on the first few hours of use we'd give the higher overall recommendation to the Bose QuietComfort 35. The Momentums are still an outstanding pair of cans, but have a higher suggested retail price (US$500, though currently only $400 on Amazon US) compared to the $350 Bose QC35. I figured we'd pick these up for a quick comparison and offload them soon after, but with a noticeable advantage in ANC and only a very minor disadvantage in audio quality, it's – surprisingly – adios, Sennheiser.

For more, you can catch up on our announcement coverage of Bose's big 2016 releases.

View gallery - 5 images