Sennheiser's CX 7.00BT occupies a strange space. Its sound quality falls short of audiophile territory, but, at the same time, its form factor is a tad too unwieldy for the casual commuter.
Rather, the CX 7.00BT is designed for someone whose primary concern is being plugged in all day, every day. The text on the back of the box concurs, pronouncing the headset "designed for a life on the go".
This is made possible by the headset's defining feature - a wraparound neckband - which has also been done by brands such as LG and Bose. The matte black band is what gives the headset its 10hr of battery life, and allows it to sit comfortably on a user's collarbones all day without shifting around.
At first, I thought that the band would make the CX 7.00BT feel bulky. I normally use lighter wireless sports headsets, which often have just a small in-line control. But, after a couple of hours in the office, I forgot that the headset was even there, and I went out for lunch with it still slung around my neck.
All the controls for the headset are hidden in the left leg of the neckband: a round power button, a start/stop button, and volume keys which double up as back/forward buttons. The headset's microphone is also located there.
At the tip of the left leg, there's the USB charging port hidden under a rubber flap. It needs 1.5hr of charge for 10hr of use. While this should be more than enough to get you through the day, I do wish that there were some sort of battery indicator to let you know when it needs rejuicing.
In terms of usability, because there is nothing like a fin or memory foam tips to keep the earbuds in place, how securely it stays in depends on how well your ears fit the silicone tips (there are four different sizes available). For some reason, my left ear was fine, but no matter how I fiddled or switched tips, I had trouble getting a good seal on the right side.
FREQUENCY RESPONSE: 17Hz - 21,000Hz
BATTERY: 170mAh Li-Po, 1.5hr charging for 10hr playback
VALUE FOR MONEY: 3/5
Once you get a good seal, though, the sound isolation is decent. When I used it in the office, I was able to happily ignore all chatter around me, to the extent that my next-desk colleague had to wave to get my attention.
Of course what you're paying for here is Sennheiser's signature sound quality. And, in this case, it is not bad - for a pair of wireless headphones.
The CX 7.00BT held its own against its fellow wireless Jaybird Freedoms ($259). Listening to Taylor Swift's airwave-dominating Look What You Made Me Do, the Sennheisers picked out the electropop strains of the chorus a lot more clearly than the Jaybirds, although it lost out to the Jaybirds in the bass department.
The lack of a strong bass punch is even more pronounced when compared against Sennheiser's wired Over-Ear Momentums. On the CX 7.00BTs, the heavy beats of the pre-chorus sounded distinctly flatter and less ominous. There's also a dip in clarity, as the CX 7.00BT swallows up the ends of Swift's words.
If you're keen on Sennheiser's neckband form factor but want slightly better performance, you may want to think about dropping $60 more for the Sennheiser Momentum In-Ear Wireless ($299, versus $239). They look identical, except that the Momentums have a leather finish and fancy red stitching. The Momentums also have a slightly more impressive spec sheet, with a frequency response of 15 - 22,000 Hz versus the CX 7.00BT's 17Hz to 21,000Hz.
• Verdict: A pair of wireless earphones designed for a user who wants music 24/7, and is willing to trade sound quality or a smaller form factor for it.