Many of the true wireless earphones we test these days are built with noise cancellation or exercise in mind. That’s great, but you typically pay a premium for active noise cancellation or a fully waterproof, gym-friendly build. Sennehsier’s CX True Wireless earphones take a different approach. For $129.95, they lack a wide array of extra features and stick to the basics—namely, audio quality. They support high-quality AAC and AptX Bluetooth codecs, which is uncommon in this price range, and they let you customize the sound signature via app with adjustable EQ. That makes the Sennheiser CX True Wireless earphones an excellent audio-first true wireless option, especially if you’re shopping on a strict budget.
Simple But Stylish
Available in black or white designs, the CX True Wireless earpieces look streamlined and simple, with a slightly boxy shape that helps provide a secure fit without ear fins. The finish may look matte, but it’s slippery, so it’s easy to send the earpieces flying when placing them in your ears or taking them out of the case.
Touch-sensitive outer panels on either earpiece control the various basic functions. A single tap on either controls playback or answers calls, a double tap controls track navigation (left ear for backward, right ear for forward), a triple tap summons your mobile device’s voice assistant, and a long hold adjusts the volume (left ear for down, right ear for up).
The charging case is short but wide, with a flip-top lid and a single status LED on the front panel. The included USB-C-to-USB-A charging cable connects to the USB-C port on the back panel. Four pairs of silicone eartips in various sizes are also included.
The earpieces have a modest IPX4 rating, which means they can withstand light splashes or misting, but shouldn’t be submerged or rinsed off. This is par for the course for most true wireless pairs that aren’t sports-focused, and the modest protection should still be enough to handle sweat or light rain. The rating doesn’t apply to the charging case, so don’t get it wet, and make sure earpieces are dry before docking them.
Sennheiser’s Smart Control app for Android and iOS works with all of the company’s headphones, including the CX True Wireless. Rather than a typical five-band, fader-based EQ, it uses slightly confusing animated curves to adjust the audio balance. You can switch to a typical fader-based EQ, but both the curves and faders have only three bands (bass, mids, and treble) rather than the more standard five bands of specific frequency ranges.
The app has plenty to offer beyond EQ, including control customization, sidetone (how much of your own voice you hear during phone calls) adjustment, toggling voice prompts, and setting auto-power-off timing. It also provides useful readouts, like what codec you’re currently listening through and how much battery life is left. And, of course, it lets you update the firmware on the earphones, with the added benefit of actually listing what bugs or issues were fixed.
The earphones are compatible with Bluetooth 5.2 and support AAC, AptX, and SBC Bluetooth codecs. Sennheiser says the earpieces can last up to nine hours per charge, with about 18 more hours of use in the charging case. These are excellent numbers for true wireless earphones, but your results will vary with your volume levels.
CX True Wireless Performance
It’s possible to create a very secure in-canal seal with the earpieces without quite getting the best-sounding audio. I first ran through my test suite wondering why the audio sounded so muddy, with overwhelming bass and dulled high-mids. This wasn’t in line what what Sennheiser headphones usually sound like, so I took the earpieces out and put them back in with a stronger twist. That did the trick, resulting in crisp high-mids while still offering plenty of bass depth. In-canal fit is a tricky thing, and everyone will have their own particular experience, but you should physically adjust the earphones themselves if they sound dulled, before playing with the EQ.
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On tracks with intense sub-bass content, like The Knife’s “Silent Shout,” the earphones deliver powerful thump and don’t distort at high, unwise volume levels. At more moderate levels, the bass depth is still strong, with reasonably matched high-frequency presence.
Bill Callahan’s “Drover,” a track with far less deep bass in the mix, gives us a better sense of the general sound signature. The drums on this track get some added thunder with strong bass boosting, without sounding unnaturally heavy. Callahan’s baritone vocals are rich in the low-mids, with a reasonable amount of treble edge to keep things somewhat crisp. This is a bass-forward sound signature, but the vocals, acoustic strums, and higher-register percussion still get plenty of high-mid detail.
On Jay-Z and Kanye West’s “No Church in the Wild,” the kick drum loop gets some added thump from the bass-forward sound signature, along with enough high-mid presence for its attack to retain its punchiness. The vinyl crackle and hiss in the background also move forward a bit in the mix, while the sub-bass synth hits that punctuate the beat are delivered with solid depth. There’s plenty of crispness and definition in the high-mids and highs when the earpieces are properly sealed in your ears.
Orchestral tracks, like the opening scene from John Adams’ The Gospel According to the Other Mary, get added bass depth that doesn’t make things sound muddy. The higher-register brass, strings, and vocals get enough treble presence to retain their place in the spotlight. Again, if the earphones sound less crisp than they should, try adjusting the fit before adjusting the EQ.
The mic offers solid intelligibility. Using the Voice Memos app on an iPhone, we could understand every word we recorded. There was some typical Bluetooth distortion in the mix, but the mic’s signal is relatively strong, and on a decent mobile connection, anyone you talk to should be able to hear you clearly.
Affordable Audio-First Earphones
Sennheiser’s CX True Wireless earphones manage to carve out a spot for themselves in the increasingly crowded field of sub-$150 wire-free models thanks to strong sound quality, terrific battery life, and high-quality Bluetooth codec support. We wish the EQ were a little less simple, but it’s still a big step up from the many models that don’t provide any audio adjustments at all. In this price range, we’re also fans of the $130 Anker Soundcore Liberty Air 2 Pro earphones, which offer surprisingly good active noise cancellation, and the $170 JBL True Wireless Flash X earphones, which are fully waterproof and better suited for exercise. If you can spend more, we’re also big fans of Sennheiser’s $200 CX 400BT model, which offers the best true wireless audio quality for the price. For $130, though, the CX True Wireless earphones are a far more affordable alternative for anyone seeking true wireless in-ears with a focus on quality audio.
