The Sennheiser Momentum Wireless headphones flick into life whenever you unfold them, waiting for standard Bluetooth pairing. You could leave them paired that way and enjoy almost all they have to offer, but for those who like to tinker, Sennheiser's Smart Control app also lets you tinker with equaliser and noise-cancellation features. It's also how Sennheiser updates the firmware on the Momentum Wireless headphones, which is not a fast process. Out of the box, the Momentum Wireless took around 30 minutes to update before I could first start testing them.
In terms of codec support, they're Bluetooth 5.0 paired with aptX and AAC. The Momentum Wireless headphones support Qualcomm's aptX Low Latency so if you are using them for privately watching video or playing games you should stay nicely in sync.
Audio quality from the Sennheiser Momentum Wireless headphones was befitting of their premium price point, with plenty of distinction between low, mid and high tones. On the Piano & A Microphone version of Prince's "Purple Rain" piano solo, I could discern just a tiny quantity of tape hiss (from the original tape, no less) behind the striking piano tones and warbling vocals, which was a detail I hadn't noticed before. The vocal separation on Frank Sinatra's "My Way" rose beautifully throughout the song, while the heavier pitch of Brian Johnson's growl in "Thunderstruck" hit home with plenty of force.
Switching to a live track – in this case, Hall & Oates's "Sara Smile" from their Greatest Hits Live album – the headphones picked up a great level of vocal detail while creating a believable live-concert soundstage wrapped around my head. You're rather spoilt for choice when it comes to audio presentation in the high end of noise-cancelling Bluetooth headphones, and the Sennheiser Momentum Wireless headphones are right up there with the very best.
The same observation isn't quite as true when it comes to noise cancelling, however. Sennheiser offers three different levels of noise cancellation. If you're not a fan of the heavily pressurised feel that many active noise-cancelling cans give, you may want to opt for Anti Pressure mode, while those who can handle it could opt for the default Max setting. If you only want a little bit of noise reduction, then the Anti Wind setting may suit.
I'm slightly spoilt because my go-to pair of over-ear noise-cancelling headphones remains Sony's exceptional WH-1000XM3 headphones, and while the Sennheiser Momentum's noise cancelling is OK, they're simply not as good as Sony's superior approach.
In most cases, you'll certainly get enough isolation out of them, although predictably the Anti Wind and Anti Pressure modes are very soft when it comes to minimising external noise sources. If you do want as much passthrough as possible, then you can switch them via the top switch to transparent hearing mode. That works well enough in public situations where you might want situational awareness so you're not flattened by a truck, but it's still painfully socially awkward if you use it while talking to someone. Taking the Momentum Wireless headphones off – at which point they'll automatically pause whatever's playing – is a superior option in every case.
Call quality is always tough to judge because there's so much more that goes into a mobile call's quality than the headphones alone, but aside from a little source scrambling for incoming calls, I had few complaints about audio pick-up during test calls.
One unique selling point for the Momentum Wireless headphones is the integration of Tile's tracking technology. Getting this working does involve setting up the Tile app on your phone and signing up for an account, but once that's done, it's trivial to check where your headphones are with a good degree of accuracy or to "call" them in order to start them buzzing if they have dropped behind the sofa. Tile will pester you a little to sign up to its premium paid service, but the basic functionality of tracking the Sennheiser Momentum Wireless headphones will work well enough without it.