Superior sound. Tailored to you. Your day-to-day may change but your enjoyment of superior sound won’t. Powered by Sennheiser’s leading audio technology, the CX 400BT True Wireless gives you total control over an exceptional sound experience. The CX 400BT offers customizable controls, long-lasting battery life and an all-day comfort design, making it the perfect choice for everyday earbuds.
Immerse yourself in amazing sound quality thanks to Sennheiser’s unique 7mm dynamic audio drivers and personalize your audio experience with the built-in equalizer and the Sennheiser Smart Control app.
Manage your music, make calls or trigger the voice assistant with customisable touch-sensitive technology built into both earbuds.
Enjoy outstanding sound quality no matter your mobile device with our wide range of audio codec support including AAC, aptX and SBC.
Experience non-stop play time with a 20 hours of battery life – 7 hours on a single charge and a further 13 hours via the charging case.
Dive into your favorite music for as long as you like with an ergonomic design made for all-day wearing.
These Sennheiser CX 400BT True Wireless Earbuds sound superb!
The thing that sets these earbuds apart from a lot of other 'True Wireless' earbuds is the way in which the associated app integrates with the 7mm dynamic drivers and the built in equalizer. I've tested out many different earbuds in different price ranges, and so far, Sennheiser have the app/earbud integration spot on.
When I first loaded the app, it has a familiar look and feel to other audio brand apps. However, the equalizer actually put a smile on my face as I configured the sound to my liking, and aurally, the differences were night and day from 'Neutral' to my 'Custom' setting. The bass became deeper, the highs gained clarity and the mids were boosted (I tend to set my equalizers in a pseudo 'U/L' shape for my optimal listening choice). It really heightened my impression of these earbud instantly. Within the app you can also set up what you want the touch sensitive buttons to do, be it answer calls, volume up/down, track forward/back etc to your liking. You can also check on the charge state of the earbuds from here as well.
The touch sensors on the side of the earbuds are very sensitive, so you may end up turning your music/sound source on and off a couple of times while placing them in your ear. Also, for note, they do not have a sensor to pause your music when you pull them out of your ear automatically. As soon as you pull them out of the case, assuming you've already paired them, they almost instantly pair to the last source they were paired to. It's seamless and very quick indeed. An audible prompt is played in each earbud.
The key to a good sound and decent bass response is a good seal on your ear. There are 4 sizes of tips included, XS/S/M/L. I found that the 'M' were slightly too small for my ears, the seal didn't maintain the bass presence that I wanted, switched to the 'L' tips and they completely sealed my ears, producing the bass tone I was expecting. However, that 'L' size did end up making my ear canal ache after a little while. Still playing around with the tips for a perfect fit.
Battery life, I've experienced pretty much what is suggested by Sennheiser which is over 6 hours playback time which is good. You can gain a further 13.5 hours of charge from the case, for a total of 20 hours or so of playback time, before a full recharge is required.
As for the fitment, I was skeptical at first on how these were actually going to stay in my ear, but with their 'twist to fit' style design, they actually lock into place in your ear very well, and shaking my head around didn't phase these earbuds at all.
Tapping the right bud 1x allows you to access a voice assistant. Tapping the left bud 1x will play/pause music, or answer/end a call. When answering a call, speech is optimized, offering a nice clean/clear connection without any distractions. Worked flawlessly for me.
In summary, these Sennheiser earbuds sound superb, especially when used in conjunction with their app! They are not the loudest, or deliver the most extreme bass you've ever heard, but they do pack a nice strong punch, with a definite 'sophisticated' sound to them, absolutely worth their price point!
This review is for Sennheiser CX 400BT earbud headphones
in the box:
Sennheiser CX 400BT earbuds
USB C charging cable
Sennheiser CX 400BT charging case in matte black
silicone adapter sets in 4 sizes (including the one already installed
thoughts and impressions:
with many options in the market, these earphones offer superior and crisp sound, a very battery life where you get 7 hours of play from the earbuds, and another 13 hours from the battery case charge, the app is simple yet efficient and offers a ton of customization for the touch controls on the earbuds. the case doesn't look super fancy but its decent looking and fits in almost any pocket.
- very good sound quality and volume
- USB C charging cable instead of Micro USB
- great battery life
- led light indicator on the case with 3 option to show battery levels: green, orange, and red
- led light indicator on each of the buds to show connectivity status
- compatible with both Android, and I OS
- earbuds auto shut off when placed in case and start charging
- case build is sturdy, not flimsy and it will withstand being in pants pocket if thats your preference.
- Bluetooth 5.1 low energy connectivity which enables the high battery life.
- the silicone attachments allow for fit with any ear size.
- highly customizable smart control app.
- earbuds are not heavy on the ear
- works well with Google assistant
- no noise cancellation
- no IPS rating therefore they are not suitable for workout and I wouldn't get them wet.
the Sennheiser CX 400BT earbuds have superior sound and very comfortable for extended every day use. the long battery life frees you from worry, and the case offers a sturdy storage and charging option. I wouldn't use them in the rain or when working out though since there is no IPS rating, and they do not offer noise cancellation so I wouldn't use them if I wanted to isolate from the outside world noise.
USB-C Charging Case
Great Case Form Factor
Great App / Sound Control
Volume control on the earbuds!
Charge light on the back by the charging port
Have to press a button to see charging status
No Side-Tone / Hear Through
Let me start off by saying that I use a lot of wireless earbuds and I’m very picky. With these, you aren’t getting some features (read: cost savings), so I won’t hold it against the product, but will note how some things could be different.
To start, these don’t have a hear-through mode. It’s where you can hear the outside and people talking, along with the tunes. If these had it, it would be insanity.
These earbuds come with, like all, different size rubber pieces to fit different ears. For me, the default one worked without any issue.
The first thing I do is charge anything that needs to be charged before I get on with using it. I noticed that the ‘full’ light is right by the charging port, not on the top or front for easy viewing.
The charge light was green in about 30 minutes and ready to go. The instructions included a QR code to get the appropriate App for my S10+, so it took away the guesswork if Sennheiser had multiple Apps out there.
When you put your earbuds in the case, there’s no indication that they are charging. You have to push a button by the light to see; amber = charging, green = full. I bet there’s a red light when the case is low, but I never saw it.
Paired these up fast by holding both ears and away I went. Rock, Reggae and Hip Hop. The sound tuning gives a few options. Move a dot around a sine wave (of sorts) until you hear what you like, or use up/down sliders; I went with the wave to adjust the sound.
Great highs, great lows and good bass. I was sold.
I went for a bunch of walks as I normally do and typically have some audio cut out with other earbuds. The Sennheiser had none of the drop-outs and there was just uninterrupted music. The earbuds didn’t move around at all, which is awesome because my other ones do
Of the past 3-4 brands that I’ve used over the past 2-3 years, I like these better than other earbuds that I have and they’ve become my daily buds. My only wish, is that there was a hear-through mode - but if they do have another version of these with it, I may jump over to those.
The Sennheiser CX 400BT earbuds are wonderful. The audio is great, they look stylish and more importantly, they’re comfortable.
Sennheiser is known for making great audio products, and this is no exception. The sound quality is excellent, and can be adjusted if you download the Sennheiser Smart Control app. The wave setting is a little strange and buggy, but the regular EQ should easily allow you to adjust bass, mid and treble frequencies to your liking. I wish there were presets to be honest. I also want to mention that I don’t hear any audio artifacts that can be common with Bluetooth earbuds.
I personally have an issue with the silicone tips on most earbuds. They either itch or become uncomfortable quickly, this includes the Galaxy Buds by Samsung. I’m happy to report that the Sennheiser silicone tips don’t bother me at all, so I’ve finally found a pair of wireless earbuds I can actually use; without going crazy.
They look a little boxier than the Galaxy Buds. They look like two boxes in your ears, but the shiny Sennheiser logo gives them a tiny bit of identity. The charging case is also significantly boxier, but it is extremely light. Much lighter than the Galaxy Bud case. I got it in black and it actually looks pretty cool.
They connect quickly to my Samsung S20+ and pairing was not an issue. So far, I’ve not experienced any dropouts or other issues while using them. They also do a decent job at phone calls with its built in microphone.
There’s no charger included, and the USB-C cable is very short, so you probably have to use your regular phone charger and cable when it needs a charge. You get about seven hours of continued use, plus another 13 hours, thanks to the charging case. That’s a total of 20 hours of use before having to charge, which is not bad.
Be careful if you use these for exercise or outdoors, because they’re not water resistant. That should be a standard these days, so plan on using these under dry conditions. They’re also noticeably more expensive than the water resistant Galaxy Buds, not that there aren’t any other earbuds in this price range. They’re still much more affordable than the Momentum 2 earbuds, also made by Sennheiser.
If you’re looking for earbuds that sound great, feel comfortable and last all day, you can’t go wrong with the CX 400BT earbuds!
I was really impressed by great this Sennheiser - CX 400BT True Wireless Earbud sounds with a Great bass not overwhelming so you can enjoy your music . Not to use for a rainy day or at the gym it’s not waterproof but it’s sounds great with a Cool sound app !
When first opening up these headphones and taking a look at them, there was already a lot to be impressed with. I really like the case and how the hinge feels when opening and closing, and the magnet latch feels plenty secure. I love the fact that these charge with a USB-C and not Micro-USB. It is so much faster to charge and that plug is getting to be more and more common. The earbuds are definitely on the more comfortable side of all the pairs I have tried over the years. They fit comfortably on my first attempt at using them, and stayed put. I did not have to change any of the earbud pieces, but there are a total of four different sizes to pick from if you find the first ones uncomfortable. Connecting to my phone was very simple, I had no hiccups there. However as soon as I started playing music, the sound sounded very flat and like it was really lacking. I immediately went back to the box to find the name of the app Sennheiser recommends using in conjunction with these headphones. It seems like the second the app connected to these headphones the sound improved drastically. It was very odd. I made no equalizer adjustments from my phone's sound or my music app. Just simply connecting the app and the headphones got the sound almost to where I was satisfied. When I found the equalizer within the app, I made adjustments to increase the bass and treble and from there I was very happy with the sound quality of these headphones. I am a bit of an audiophile and I tend to always turn up the bass and treble no matter what I am listening to and these were no exception. Once I had the headphones sounding the way I liked them, I went through a variety of genres of music, as well as YouTube videos and movies, all sounded fantastic! Watching an action movie was really impressive as the bass was perfect and it felt like surround sound. I swore I could hear every little noise happening in the movie. Another thing that I loved (found in the app) is the ability to customize the touch controls. I noticed that factory settings of these headphones had nearly opposite touch controls as my other headphones I spend several hours a week using and know the controls really well on. An easy fix though in the app and within seconds I was able to make the touch controls the exact same as my other touch sensitive headphones. I thought that was a very neat function. Overall these are excellent headphones, the comfort, the sound quality, battery life, and ease of use make these a no brainer to recommend. They are extremely versatile, I have been able to wear them while laying in bed, while working out, and while riding a lawn mower and no matter the setting, the sound was great and they stayed in place. I love these headphones.
I've had these for a while and used them a lot. They stand up to the hype the manufacturer says about them. Strong battery life. Totally easy pairing on multiple devices and platforms. They seem to me to be really sensitive to sound to the point I find myself lowering the volume on my device (a great problem to have).
Ease of Use
5 out of 5
5 out of 5
5 out of 5
I would recommend this to a friend
Ease of Use
4 out of 5
5 out of 5
5 out of 5
Rated 5 out of 5 stars
Best sound quality for $100
Owned for 2 months when reviewed.
Strictly for sound quality alone this is a steal for $100 (same drivers as the Momentum 2's), bought mine when it was $50 more, using Spinfit CP-360's with these.
The analysis of all aggregated expert reviews shows that the reviewers are positive about size, reliability, bass quality and durability. Editors are less positive about noise isolation and have mixed opinions about treble quality. Using an algorithm based on product age, reviewers ratings history, popularity, product category expertise and other factors, this product gets an alaTest Expert Rating of 93/100 = Excellent quality.
TechRadarRating, 4.5 out of 54.5Simon Lucas on September 4, 2020
Sennheiser CX 400BT True Wireless reviewSennheiser finally engages with the true wireless earbuds mainstream – with fairly predictable results.
Sennheiser CX 400BT review: Great-sounding mid-range wireless earbudsWith its third set of true wireless earbuds, Sennheiser's CX 400BT is a more affordable option. The company manages to mostly retain the stellar sound quality from the Momentum True Wireless 2 along with customizable and reliable touch controls
rtings.comRating, 3.5 out of 53.5Dagobiet Morales Alfaro on November 25, 2020
Sennheiser CX 400BT True Wireless ReviewThe Sennheiser CX 400BT True Wireless are sleek in-ears that resemble the Sennheiser MOMENTUM True Wireless 2 in look and performance. They have a similarly warm
Sennheiser CX 400BT True Wireless review: Enjoy excellent audio for lessSennheiser's first true wireless headphones outside the Momentum range offer the same superb sound quality without such a steep price tag
Sennheiser CX 400BT ReviewIn a world of convenient but pricey Apple AirPods and remarkable sound quality from Sony and Bose, it can be hard to stand out. With the Sennheiser CX 400BT, it's about value. Sennheiser brings quality across the board to a reasonable price with
A:AnswerNo, they are not. They are basically the same as the Sennheiser - MOMENTUM True Wireless 2, just without the active noise cancellation and transparent hearing mode. They’re also $100 dollars cheaper, so you have to decide whether those other two features are worth the price difference or not.
A:AnswerThe right earbud WILL work independently, however the left earbud DOES NOT work independently of the right one. The left seems to require connection to the right one in order to work. As soon as the right earbud looses power or is returned to its case it will disconnect.