The Sennheiser CX 400BT True Wireless earphones are many things but it’s no question they follow one of the German audio company’s hard-to-remember naming conventions.
A better way to describe them would be the more affordable version of the S$449 Sennheiser Momentum True Wireless 2, an exceptional pair of truly wireless Bluetooth earphones I tested earlier this year.
There are trade-offs here, which I’ll come to in a moment, but the new S$299 CX 400BT’s biggest selling point is the excellent audio quality that is more or less similar to its predecessor.
The new earphones utilise the 7mm dynamic drivers you find in the more expensive model, which bring a good amount of clarity, detail and control to your music.
New Order’s Love Vigilantes on Tidal shows off a good amount of transparency, without any clutter that gets in the way of the mid-range. The guitars and drums, as well as the vocals, come across with a “live” quality that belies the small size of the earphones.
Indeed, the airiness and openness I found in the Momentum True Wireless 2, which I remember fondly, is also similar in the more affordable CX 400BT. The sound comes across as natural, not made up.
The bass guitar on other “master quality” New Order tracks is a good example of this good balance. You hear the low hum while not feeling it is exaggerated for effect.
This is one important quality if you don’t want a headache from listening to muddy bass as well as brittle treble, which unfortunately too common on lesser earphones.
Good news is, the new Sennheiser earphones also adapt to different sonic material well. Listening to Everything But The Girl’s Wrong, for example, I like the fast-paced presentation that sheds any unnecessary weight while retaining the detail on the track well.
Firing up something more complex, like the Tenet movie soundtrack, which has several high-pitch and deep-bass components that come up in an instant, I find that the earphones display a dynamism that handles the demanding content well.
They don’t lose a beat, despite the rapid starts and stops, sudden highs and lows. To be sure, there’s little to fault the Sennheiser sound here, even when it is left to default, out of the box.
Personally, though, I tend to dial down the bass and push up the treble, because most earphones and headphones today often tune up the low-end too much for my liking.
This is where the Sennheiser Smart Control app comes into play. Though less full-featured than Sony’s, for example, it lets you make the most important adjustments to the equaliser, which easily modifies the audio to your liking.
In terms of audio codecs, the CX 400BT earphones support SBC, AAC and aptX, though there is no aptX HD, which promises better quality streaming from your phone, via Bluetooth.
Still, if audio quality alone is what you’re looking for, I’d say Sennheiser’s new earphones are top notch and are a welcome alternative to the more expensive Momentum True Wireless 2.
The difference, however, is quite obvious in other departments. For one, there is no active noise cancelling. Yes, the earphones’ snug fit do help to keep out noise but an electronic option does keep out more ambient sounds.
The second thing you don’t get is the clearly more premium feel of the Momentum True Wireless 2. The CX 400BT’s charger case loses the fabric exterior for a more utilitarian plastic finish, though it still has the charging indicator which is most important to know if your earphones are ready.
The ear buds themselves also seem to be more simply styled. They lack the etched lines that you find on the more expensive predecessor, though you won’t notice this when you put on the CX 400BT, to be fair.
More importantly, the earphones, which weigh only 6 grams each, are comfortable to wear for hours. That’s even when you’re blasting out rapid, big sounding mechanical noises from the Tenet movie.
For their audio quality alone, I’d give the CX 400BT earphones top marks. I am also happy with the smart touch controls, which you can customise on the app to start or stop a track, for example. There’s a triple-tap option that is open for you to fiddle with.
Impressive too is the battery life, which is said to last up to seven hours with the earphones fully juiced up. The charging case’s additional charge offers a total of 20 hours playback time.
With the CX 400BT, I don’t remember running out of juice because I often went on to do other things after a couple of hours of listening to music and slotted the ear buds into the charging case.
If you don’t need active noise cancelling and audio quality is the most important factor, then I’m confident the Sennheiser CX400 BT are a pair of truly wireless Bluetooth earphones that are hard to go wrong with.
What gets in the way of an unreserved recommendation is the competition in this crowded earphone segment. I’m thinking of Sony’s WF-1000XM3, which offers excellent value for under S$300 now, because of its audio quality and active noise cancelling.
I don’t have the Sonys with me for a side by side comparison with the Sennheiser CX 400BT earphones, but I’d be quite torn between the two similarly priced options. If you were to choose, I’d advise you to give both a listen.