The Sennheiser CX 400BT is a winner when we talk about the design and the audio performance. The earbuds come with customisable touch controls and they also offer a pretty good battery backup. The only thing we felt was missing was the features like ANC, Ambient Mode and wear detection.

The Sennheiser CX 400BT are no ordinary pair of mid-range wireless earbuds. Their balanced, detailed sound, excellent comfort and myriad of features ensure they stand out in a crowded market.

Great sound, Good app and features, Respectable battery life, Comfortable fit

No ANC, No water or sweat resistance

“The sound is incredible, but the cost of a lowered price is a bunch of missing features.”

Superb sound quality; Responsive and customizable controls; Highly adjustable onboard EQ

Lacks features for the money; Possible fit and comfort problems

Contrary to the many reviews I read online before purchasing these earphones, they just would not stay in my ears. I tried all the different size tips on them but it didn't seem to make much difference. I've been using the old Apple wired earphones for years as they fit really well for me, but finally made the move to wireless with these and they didn't fit at all. Have switched to Airpods 2 now and they fit perfectly. Otherwise though, the Sennheisers are great. Very light weight, the touch controls are great and easy to use, and the sound quality is excellent. If they fit your ears, you'll be set. If not, they're pretty much unusable. Good luck figuring it out lol.

Sennheiser has a reputation for top-quality sound, and both the Momentum True Wireless and its sequel, the Momentum 2 True Wireless, scored very highly on sound quality when we reviewed them. But along with that excellent sound comes a fairly steep price — $300 is what you’ll pay for these earbuds. Clearly, that eliminates a lot of potential buyers. So the challenge for Sennheiser was to create a set of true wireless earbuds that cost less without sacrificing the biggest reason for buying them in the first place: High-quality sound. Its answer to that challenge is the $200 CX 400BT True Wireless. Their price is definitely more palatable, but do their overall feature set and performance make them a worthwhile investment when you consider how many other excellent earbuds can be had for the same, or similar, money? Let’s take a look. The CX 400BT’s relatively plain cardboard box contains the earbuds, their charging case, a set of four sizes of silicone eartips (large, medium, small, and e...

Superb sound quality; Responsive and customizable controls; Highly adjustable onboard EQ;

Lacks features for the money; Possible fit and comfort problems;

The headphones come into their own where you can plug straight into an existing handsfree or remote control unit

Mobile phone headset upgrade potential; Good sound; Carry case

Bass not so good; Cable options can be inconvenient

The Sennheiser CX 400BT is a really solid mid-range set of TWS earphones, but bargain hunters may want to find something else if ANC is important to them. Still, having high-end audio hardware at a mid-range price point is a good bargain in our opinion.

Sound quality; In-app equalizer; Small case; USB-C charging; AAC and aptX support

Cost; No ANC; Large earbuds

Sennheiser’s first true wireless headphones outside the Momentum range offer the same superb sound quality without such a steep price tag

Superb sound quality; Stable connection; Quick; seamless pairing

No splash proofing; No ANC; Not cheap

The Sennheiser CX 400BT earphones deliver some of the best on-ear controls and audio performance you'll find in a true wireless pair.

Excellent audio performance with rich bass depth and detailed highs; Comprehensive; intuitive; and customizable on-ear controls; App features adjustable EQ; Secure fit

Pricey; Not ideal for gym use

Sennheiser’s first true wireless headphones outside the Momentum range offer the same superb sound quality without such a steep price tag

Superb sound quality; Stable connection; Quick, seamless pairing;

No splash proofing; No ANC; Not cheap;