Buy now at No Cost EMI

No cost emi

CX 400BT Black


Inclusive of all taxes

No cost emi available on all credit cards for 6,9 and 12 months

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 new Sennheiser CX 400BT True Wireless gives you total control over an exceptional sound experience. With intuitive customizable controls, long-lasting battery life and a design made for all-day comfort, they are the ideal, uncompromised choice for people that are passionate about great sound.



Better sound. Better control.

Whether you’re in the mood for calming tunes or crave some thrilling beats, the bespoke drivers of the new Sennheiser CX 400BT True Wireless deliver high-fidelity sound with deep bass, natural mids and a clear, detailed treble. Plus, you can personalize your listening experience with built-in equalizers to enjoy amazing sound quality that’s tailored to you.

Premium sound. Any device.

No matter where you stand – iOS or Android – you’ll always get to enjoy the outstanding sound quality of the new CX 400BT True Wireless earbuds. Thanks to our wide range of audio codec support including SBC, AAC and aptX, premium sound is guaranteed with any mobile device.

Anytime. All the time.

Never miss a beat throughout the day with 20 hours of battery life – 7 hours on a single charge and a further 13 hours with the small, sleek and compact charging case. The new CX 400BT True Wireless earbuds are designed to ensure you get premium sound wherever you go.

Minimalist Design. Stylish comfort.

The new Sennheiser CX 400BT True Wireless is made for those who enjoy diving into a long playlist, a lively audiobook or a loving phone call. Available in black and white, they have an ergonomic design created for all-day comfortable wearing.

Smart Control App

Create your sound experience.
Pair your Sennheiser device with our Smart Control app.
Customize what you hear and how you interact with your Sennheiser device.

Enhance what you hear.
Adjust our intuitive equalizer to perfect your listening experience

Define your touch controls.
Control your music, voice assistants, and calls with adjustable touch controls you assign.

Decide what you hear.
Use the transparent hearing settings to determine how much of ambient noise you want to hear.

Technical Data


59 x 33.8 x 42.3 mm (earbuds and charging case)


49g (both earbuds and charging case) 6g (single earbud) 37g (charging case)

Package dimensions

(L x B x H) 170 x 115 x 47 mm

THD, total harmonic distortion

<0,08% (1kHz / 94dB)

USB Standard



2 years

Frequency response (Microphone)

100 Hz to 10 kHz

Bluetooth Version

Bluetooth 5.1 compliant

Supported Profiles


Frequency response

5 - 21,000 Hz

Ear coupling

In-ear, closed acoustics

Charging time

1.5 h for full charge / 10 min for 1 h playtime

Power supply

5 V⎓ 650 mA max

Battery Specification

Built-in Lithium-Ion rechargeable batteries


SBC, AAC, aptX™

Battery time

Up to 7 hrs music playtime with earbuds Up to 20 hrs music playtime with charging case

App support

Sennheiser Smart Control App for iOS™ and Android™

Speaker type

Sennheiser 7mm dynamic driver

What's in the box?

  • CX 400BT True Wireless Earbuds
  • Silicone ear adapter sets (XS, S, M, L)
  • Charging Case
  • USB-C Cable
  • Quick Guide & Safety Guide


Safety instructions and regulatory information

Quick Guides

Links to FAQ pages

Instruction Manual

EU Declaration of Conformity

Related Items