Sennheiser CX 400BT True Wireless
‘Affordable’ Sennheisers have Apple AirPods firmly in their sights.
Having established its credentials as a high-end true wireless earbud front-runner with two generations of its Momentum True Wireless, Sennheiser’s now turned its attention to the less rarefied area where Apple, Microsoft, Sony and all the rest duke it out. At $299, the CX400BT are pitched right into the thick of the action.
Happily, the CX400BT are specified to compete. They have aptX Bluetooth connectivity, with SBC and AAC codecs catered for too; they have app-based EQ adjustment; they have responsive touch-controls (which can be customised in the app); and they can be operated using Google Assistant or Siri.
They share the same 7mm full-range dynamic driver as their more expensive Momentum True Wireless 2 siblings too, though they go without that model’s active noise-cancelling technology. Thanks to four sizes of eartip in the packaging and the twist-to-fit arrangement, there’s actually quite a lot of passive noise-cancelling delivered once you’ve established the correct fit.
On an aesthetic level, there’s not a great deal to discuss – Sennheiser has never been the showiest headphones brand around, and anyone expecting a little Apple or Microsoft-style weirdness is going to be disappointed.
‘Extended’ in this instance means a battery life of up to seven hours from the earbuds themselves – there’s another 13 hours held in the charging case. A total of 20 hours’ battery life is by no means a disaster, but it puts the Sennheisers at a mild disadvantage compared to any number of nominal rivals.
The word ‘disadvantage’ doesn’t apply where the sound of the CX400BT is concerned, though. They’re an open, eloquent and prodigiously detailed listen, with some particular talent where texture and timbre are concerned.
About the only area where the Sennheisers overplay their hand is at the top of the frequency range. Unlike the more expensive Momentum True Wireless 2, which are the very model of high-frequency good taste, the CX400BT are confident to the point of recklessness. Eric B & Rakim’s ‘Microphone Fiend’ demonstrates the treble edginess well – the Sennheisers are constantly threatening to become uncomfortably hard, and it’s a trait that becomes more pronounced the louder you listen or the more trebly the recording you’re listening to. It’s possible to dial down this top-end excitability in the control app, but you’ll need to take care you don’t neuter the sweet midrange response at the same time.
They’re not the most glamorous nor the most distinctive – but Sennheiser’s new CX400BT true wireless earbuds have it where it counts. They sound open and articulate, and if there’s detail in a recording to be extracted, you can rely on them to do just that.
Simon Lucas