“They pack some of the best sound you'll find in an affordable set of earbuds.”
- Excellent sound quality
- Customizable EQ
- Precise and customizable controls
- Side-tone for phone calls
- Good battery life
- IPX4 water resistance
- No in-ear sensors
- No transparency mode
- No wireless charging
- Might be hard to get a secure fit
True wireless earbuds have always presented a dilemma. Unlike their wired cousins, wireless earbuds require a vast array of components, like batteries, charging cases, Bluetooth radios, amplifiers, etc. All of these drive up the cost, making it hard to deliver high-quality sound at affordable prices. Sennheiser — a brand with an enviable reputation for superb sound — has been experimenting with the line between quality and affordability.
Its first shot was the $200 CX 400BT, which it released in 2020, a set of true wireless earbuds that delivered on sound but lacked a lot of features we would expect at that price. Sennheiser’s second act is the $130 CX True Wireless. Do these buds achieve that magical balance of price versus performance? We put them to the test to find out.
What’s in the box?
Sennheiser is part of a growing list of companies that have made their packaging highly recyclable. The CX True Wireless’s box is plainly printed cardboard and even the small packages that protect the included ear tips are paper-based. You won’t find a hint of plastic or foam anywhere. Inside, you’ll find the earbuds, their charging case, four sizes of ear tips, a short USB-A to USB-C charging cable, and some paper documentation.
Design
Visually, the CX True Wireless are almost indistinguishable from the CX 400BT. Both the charging case and the earbuds have identical proportions. There are small differences if you look closely: The CX True Wireless have more subtle branding, which some will no doubt prefer, and their charging case has dropped the dedicated pairing button from the CX 400BT’s case. The touch controls now use a matte plastic finish instead of a glossy finish.
If you take one thing away from this review, here it is: The CX True Wireless are a sonic bargain.
The earbuds remain a bit on the bulky side, and they won’t win any awards for style. But the rounded-box shape makes inserting them into your ears without accidentally triggering a control way easier than many other earbuds — it also makes it easier to remove and replace them in their charging case.
One thing that has changed from the CX 400BT is the addition of an IPX4 rating for water resistance. This puts the CX True Wireless on par with other earbuds like the AirPods Pro. They won’t survive a dunk in the pool, but at least now you can take them to the gym, the track, or anywhere you like to sweat, without worrying about your earbuds.
Comfort, controls, and connections
Unfortunately, because the CX True Wireless inherited their size and shape from the CX 400BT, they also inherited the way those earbuds fit, which is to say, they may not feel comfortable. In order to get a really comfortable, secure fit, I ended up grabbing a set of Comply Foam ear tips — the same ones I ended up using on the CX 400BT to deal with the same situation.
Sennheiser remains one of the few companies that really understand what it takes to do touch controls right.
Now, to be fair, the silicone ear tips Sennheiser includes with the CX True Wireless will probably work for a lot of people and I’d never say they weren’t comfortable. But they definitely don’t offer as secure a fit as foam, nor do they seal your ear canals as effectively. If you encounter the same thing, just buy some Comply tips from Amazon for a few bucks — you’ll thank me for it.
The CX’s touch controls are superb. Sennheiser remains one of the few companies that really understand what it takes to do touch controls right. The control surfaces are large and unambiguous — getting consistently accurate taps is effortless. As a bonus, a subtle tone will confirm that you tapped correctly.
Sennheiser’s Smart Control app lets you customize these controls. Single-, double-, and triple taps can all be assigned your function of choice, and you can select a different function for each earbud — handy if you intend to use the earbuds independently (which you can do for both music and calls). You get everything you need: Play/pause, track skip forward/back, trigger your voice assistant, and volume up/down. The only function that can’t be altered is volume, which requires the long-tap gesture if you want to use it.
Pairing with either iPhones or Android devices is easy, even if the CX aren’t equipped with Google’s Fast Pair — a few taps and you’re done. If you’re on an iPhone, you’re limited to the good, but lossy AAC codec, meanwhile Android users get to enjoy the slightly higher-quality aptX codec. But regardless of your source device, you won’t be able to roam very far. The CX have one of the shortest wireless signals I’ve ever tested — they started to break up when I put just 20 feet between me and my phone. If you keep your phone on you, it shouldn’t be a problem. But if you like to leave your phone in a bag, a locker, be prepared to stay close by.
Sound quality
With the included silicone ear tips, I found the CX True Wireless somewhat anemic for bass, but this was purely a function of fit. Once I swapped them for the foam tips, the sound improved dramatically. If you take one thing away from this review, here it is: The CX True Wireless are a sonic bargain. They deliver an impressively detailed and precise performance that comes incredibly close to earbuds from Sony, Bose, JBL, and Master & Dynamic that can cost anywhere from $250-$350.
The soundstage is both wide and deep, and purists will like that Sennheiser’s factory EQ settings give you a flat/neutral signature. But I typically find neutral EQ sounds boring at my preferred volume levels, so I love that the Smart Control app gives you two ways to visualize and change the emphasis on lows, mids, and highs, and create presets when you find a setting you like. You can significantly energize the lows and highs without losing detail in the mids.
I spent a fair amount of time bouncing from one genre to another, and whether it was jazz, pop, metal, or hip-hop, the CX True Wireless handled them beautifully. If you’ve never listened to really decent earbuds, the CX will also give you one of my favorite experiences: Hearing a detail in one of your favorite tracks that you’ve never heard before or rendering it in a way that puts a smile on your face.
When conditions are relatively quiet, your voice will be nice and clear, with very little compression or wobble.
One track that certainly did this for me is Melanie Martinez’s High School Sweethearts. At the one-minute mark, Martinez transitions from her breathy and F-bomb-laden intro into the body of the track, at which point you can hear someone writing on a chalkboard. The CX place that unmistakable scratchy sound behind Martinez’s voice so precisely, it feels like you could look over her shoulder and see the person doing the writing. It gave me goosebumps.
Battery life
The CX 400BT promised seven hours of battery life per charge, with a total of 20 hours when you included the charging case — acceptable but hardly noteworthy, especially for earbuds without active noise cancellation (ANC). But the CX True Wireless are a step up, with nine hours per full charge and a total of 27 hours with the case.
A quick charge of 15 minutes will get you an extra hour of play time. These put the CX True Wireless on par with some of the best earbuds for stamina — a welcome improvement.
Call quality
Calling on the CX True Wireless is about average for true wireless earbuds. When external conditions are relatively quiet and there’s no wind, your voice will be nice and clear, with very little compression or wobble. This must be the “speech optimized sound” that Sennheiser refers to in its description of the earbuds.
But the same can’t be said for times when there’s wind or loud sounds nearby. At these times, the microphones struggle to keep your voice consistently clear. Since so few earbuds do an awesome job of this, I can hardly fault Sennheiser, but just keep it in mind: These are earbuds for making calls at your desk or while waiting for your flight — not for when you’re jogging, cycling, or walking near heavy traffic.
These were my observations when testing the CX 400BT too, but here’s where the CX True Wireless once again improves on its more expensive predecessor: The CX True Wireless have adjustable side-tone, which lets you hear your own voice much more clearly during calls. It works really well, but I did find that it was tricky to adjust the amount of side-tone while on a call.
Anything missing?
The CX True Wireless have really hit a sweet spot in terms of price and sound performance and they’ve even managed to deliver really good battery life, but there are still some features you might miss. There’s no hear-through (transparency) mode, which is surprising given the side-tone calling feature — these two often go hand-in-hand.
There are no in-ear sensors that can be used to auto-pause your tunes when you pull out an earbud. Given the lack of transparency mode, that’s something you’ll be doing a lot if you want to talk to someone in real life.
The charging case lacks wireless charging — a minor annoyance perhaps, but it’s becoming standard on a lot of earbuds that cost less than the CX.
It’s true that there’s no ANC either, but that’s one feature I’ll give Sennheiser a pass on at this price.
Our take
For folks who love high-end sound quality but lack the funds to go wild on the best true wireless earbuds, the CX True Wireless are a great buy. As long as you can get along without a few features like transparency mode, and are willing to buy some third-party ear tips if the sound or fit doesn’t work for you, I think you’ll be really happy.
Is there a better alternative?
There are tons of great true wireless earbuds between $100-$130 that can outshine the CX True Wireless on features. The second-gen Amazon Echo Buds come to mind, as well as the Soundcore Life P3, and the Jabra Elite 75t. But none of these can beat the CX for sheer sound quality.
Ironically, now that Sennheiser has seemingly discounted the CX 400BT to just $100 — it might just be the best alternative. Same great sound, but with shorter battery life, no water protection, and no side-tone on calls. If you’re ready to give those up for a $30 savings, giddy up!
How long will they last?
Though it can be hard to predict, the CX True Wireless look better built than a lot of other true wireless earbuds. Fit and finish is excellent and Sennheiser backs them with a two-year warranty which speaks a lot to the company’s confidence in its product. The industry standard is just one year. With IPX4 protection and a good starting battery capacity, they should last you for many years of use.
Should you buy them?
Yes. The CX True Wireless solve the problem of how to get great sound on a limited budget.
