Noise-cancelling (NC) and Bluetooth together of course deliver the ultimate in convenience — handsfree without cables, noise-free by cunning cancellation of lower frequencies. Yet it’s notoriously hard to achieve with distinction. As we’ve seen on many wireless NC designs, problems come when deciding how to ‘voice’ the headphones. Do you create the best possible cabled sound and then hope Bluetooth won’t muck it up too much? Or do you assume most people will use Bluetooth, voice it for that and let the cabled performance suffer? Or a compromise? Noise-cancelling adds a third effect on the sound, either cabled or wireless, so the designers are left seeking a solution between four separate set of sonics.
Audio-Technica certainly has a headstart in delivering cabled headphone sound, having done so reliably for decades. The NC700BT feels as solid as the company’s usual designs — all in a durable matte black plastic, with memory foam earpads, the headshells able both to twist flat around your neck (facing down) or to fold up on the other axis for very compact storage. Comfort was high throughout use, the headband especially so, spreading the point of contact so that this relatively light design felt almost weightless, exerting no significant pressure around the ears. You could easily kip on the plane wearing these.
All the controls and indicators are on the left headshell (see below), along with the connectors for USB charging and the cable, if you’re using it.
The only physical switch is to power them on, but the left earshell has touch points — tap in the middle to play/pause (and to answer calls), swipe up/down for next/last track, tap top or bottom for volume up/down. This all worked well, although the volume changes are accompanied by loud and redundant bleeps, and also, when used with an admittedly ageing iPhone 5s, only raised the volume to whatever was set on the phone, requiring the phone itself to be used to go higher, rather than the full range being controlled back to the phone by AVRCP, in the Bluetooth profile. (The manual does say “The volume control of some devices may not work well with the product.”)
There’s not much to tell on the audio tech; the drivers are an unspecified type of 40mm diaphragm, likely Mylar or similar being the diaphragm material.
Balanced for Bluetooth
We used these headphones in their various listening modes for the best part of a month. We reckon that, sensibly enough, the balance has been optimised for active Bluetooth use, which is how most users will undoubtedly operate them. In direct comparison we thought the passive cabled sound to be just a little boxy. Lou Reed’s vocal on Walk On The Wild Side was rather shut in, soft in comparison to the other three options, lacking airiness and cut-through, leaving things tilted a little too full in the upper bass. But that’s not to criticise the overall quality — though not entirely natural, it was a detailed and powerful sound, musically enjoyable, and the usual credit to the brand.
Keeping the cable attached we switched the headphones on, so engaging the active circuits and noise-cancelling. We note this changes the impedance of the headphones from 35 ohms to 150 ohms, though there’s no drop in level, the active circuits and a higher sensitivity in this mode presumably compensating. Again there’s plenty of level available, while the active mode brightens things up nicely, at