Sennheiser, along with Bose and Bang & Olufsen, is one of the most respected brands in the world when it comes to audio equipment, with a well-deserved reputation for excellence. However, what you may not know is that the company doesn't just create equipment for audiophiles - it also has a well-rounded line of business equipment.
As well as conferencing packages like the TeamConnect Wireless, it also produces headsets for call centre operators, sales representatives and business collaboration. The best of these are the Sennheiser MB 660s, a pair of wireless headphones that combine Sennheiser's superb audio expertise with some seriously nifty business features.
Sennheiser MB 660: Design
When it comes to headphones, there's two things you want above all else: sturdiness and comfort. The MB 660s deliver on both fronts. The cushioned, leather-effect ear cups can be worn all day (and we mean all day) with zero discomfort, and the padded band is equally comfortable. There's a high degree of adjustability in both the band and the articulated joints where it meets the cups, so you can find a good fit regardless of your head shape.
Reliability is similarly good. The MB 660s can be folded up to conserve space, and although they come with a carry-case for safe transportation, we've been folding them up and slinging them in a bag on an almost daily basis for months with no apparent ill-effects. It's definitely fair to say that these headphones are more than capable of shrugging off the various knocks and scrapes which normally occur with everyday use.
As an added bonus, they also look great. Finished in matte-black plastic with subtle brushed-aluminium detailing, they're classy and understated, with a premium look that isn't overly garish or ostentatious. They're more than professional enough to wear around the office, or even to take with you to client meetings.
Sennheiser MB 660: Sound quality
As you'd expect from a company with as rich and distinguished a pedigree as Sennheiser, the audio quality on display here is absolute impeccable. It uses Qualcomm's aptX Bluetooth audio technology, so bass is rich and full, mid-tones are warm and the higher ranges are crisp and defined. The highs and mids are slightly more forward than the bass, but this isn't much of an issue - especially as it makes phone calls clearer.
After all, the MB 660s aren't just designed for blasting out Phil Collins’ greatest hits; they're first and foremost built for business use, so call quality is at least as important as music - if not more. Thankfully, this is also excellent; the MB 660s inbuilt microphones do a great job of picking up only the audio that you want them to, using various clever technologies to filter out background noise from busy offices or environmental interference like wind, focusing in on just your voice. This isn't always perfect - if you're in a room with awkward acoustics, the conversation can end up being difficult to hear for the listener - but by and large, the quality is superb.
There are various 'effect modes' which optimise the sound for things like movies or speech, or you can use Sennheiser's CapTune app to fine-tune the audio to your personal preference, including adjusting the level of noise cancellation.
Sennheiser MB 660: Connections and battery life
The MB 660s feature Bluetooth 4.2 for wireless connection and NFC for rapid pairing with smartphones and other devices. There's also a 2.5mm jack for cabled connections, which is handy for use on planes or with DACs and other analogue devices.
Charging is done via a microUSB connection, which is a blessing - we've seen a lot of headphones with proprietary cables or a 2.5mm jack for charging, which can be incredibly inconvenient if your battery dies and you're away from your cable, while microUSB is much more common.
The battery itself is rather hardy; even with semi-constant use throughout the course of the day, the MB 660s generally managed to last a couple of days before needing a top-up. Sennheiser quotes a battery life of up to 30 hours, and our experience indicates that this is pretty much accurate. Plus, the charge time of just three hours from flat means you can juice back up again rapidly.
Sennheiser MB 660: Features
As well as the various features that Sennheiser has included to maximise call quality, there are also a number of smart tricks that add to the overall experience of the MB 660s. One of the stand-out features of the MB 660s is their noise-cancelling technology. For those who aren't familiar, this is a form of noise-cancelling which detects ambient sound and uses a matching but opposite soundwave to cancel it out.
The result is that the level of general noise you'll hear while wearing these is vastly reduced. It won't completely deaden the noise of the outside world though - Sennheiser has engineered its ANC technology to ensure that certain sounds will still cut through to a certain extent, such as train announcements or colleagues speaking to you. It is, however, faultless at filtering out the general hubbub of a busy, open-plan office, to the point where it's become a permanent fixture of our working lives.
As you'd expect, it features touch controls for various functions. A touch sensor on the right ear cup controls various media and call functions, including answering and rejecting calls, holding, muting and redialling, as well as playing, pausing and skipping tracks and adjusting volume. There's also a version that's certified for use with Microsoft's Skype for Business, ensuring maximum compatibility with Redmond's VoIP tool.
Sennheiser MB 660: Verdict
The Sennheiser MB 660s are amazing. They're ostensibly a business tool, and it's hard to argue that they're not qualified in this area, with great call quality and smart business features to ensure maximum productivity. We didn't fall in love with them for their enterprise credentials, though.
No, the reason we now take them everywhere we go is that they are hands down the best pair of headphones we've ever owned. On a purely technical level, the audio quality is fractionally behind the very best in the business, but it's still excellent. What's more, any minor deficiencies they do possess are more than made up for by the outstanding noise cancelling and the unparalleled comfort they offer.
And when we say we take these headphones everywhere, we mean it; since we received our review unit in November 2017, there has scarcely been a day when they haven't been within arm's reach. We generally wear them for at least four hours a day, and we honestly can't imagine ever getting tired of them. They drown out the noise of a bustling commute, a loud office or a humming plane cabin, and they're so comfortable that, honestly, we quite often forget we're wearing them.
These headphones combine the best in a unified comms headset with the absolute pinnacle of audio technology. The only catch is the price; with an RRP of £385 before tax, they're decidedly expensive. In fact, they're more than £100 more expensive than the excellent Bose QuietComfort 35s.
That said, what you get for that price that you don't get from the QC35s is the excellent array of business features. Besides which, we'd argue the MB 660s are more comfortable and feature better ANC than Bose's offering. Still, it's a high price to pay - although if you've got the money, you can rest assured that you're getting the best.