CX 400BT True Wireless In-Ear Headphones (White) Product Image

CX 400BT True Wireless In-Ear Headphones (White)

Product Description

Take control of your wireless audio experience with the CX 400BT True Wireless In-Ear Headphones from Sennheiser. Utilizing the Sennheiser Smart Control app for iOS and Android devices, you can fully customize the functionality of the CX 400BT's integrated touch controls. Both earbuds feature touch controls and you can set what a single, double, or triple tap does, as well as what happens when you tap and hold the side of the earbud. Options include music management functions and engaging your phone's digital assistant software.

Sennheiser engineered the CX 400BT headphones to ensure what you play through them sounds as good as possible. Featuring 7mm dynamic drivers and support for multiple codecs, including aptX. With dual integrated MEMS microphones, these true wireless headphones can be used for more than music. Pair them with a smartphone for hands-free wireless calls or give voice commands to your phone's digital assistant. Music, calls, and more can be enjoyed for up to 7 hours on a full charge, with an extra 13 hours provided by the included charging case.
Item Type
Number of Included Headphones/Receivers
Number of Included Transmitters
Number of Included Headsets
Number of Included Transceivers
Earpiece Design In-Ear (Intra-Aural), Closed-Back
Earpiece Swivel
Earpiece Connection / Wearing Style
Number of Earpieces
Sound Field
Earpad Size
Driver Type Dynamic
Number of Drivers 1, per Earpiece
Driver Size 0.28" / 7 mm
Magnet Type
Voice Coil
Active Noise Cancellation No
Controls/Microphone Location Controls: Left Earpiece, Right Earpiece
Microphone: Left Earpiece, Right Earpiece
Full Remote OS Support Not Specified by Manufacturer
Sensors Touch
Contact Pressure
Frequency Response 5 Hz to 21 kHz (Wireless)
Resonant Frequency
Matching Tolerance
Maximum Sound Pressure Level (SPL) 114 dB at 1 kHz
Maximum Power Handling
Functional Bias Voltage
Electrostatic Capacitance
Output Power
Volume Limiting
Noise Attenuation
Total Harmonic Distortion (THD) 0.08%
Channel Separation
Storage Capacity
Number of Mics 2
Beamforming Support Yes
Diaphragm Size
Mic Boom Location
Pickup Pattern
Noise Canceling
Frequency Response 100 Hz to 10 kHz
Operating Voltage
Maximum SPL
Equivalent Noise Level
Wireless Connectivity
Wireless Transmission
Number of RF Channels
RF Bandwidth
Max Systems per Setup
Wireless Modulation Bluetooth: π/4 DQPSK, 8DPSK, GFSK
DECT Standard
Duplex Mode
RF Channel Access Method
Speech Encoding
Transmission Speed
Approximate RF Sensitivity
Supported Audio Codecs AAC, SBC, aptX
Bluetooth Profiles
Bluetooth 5.1
Bluetooth Power Class 1
Wireless Range
Frequency Bluetooth: 2.4 GHz (2.402 to 2.48 MHz)
Transmitter Power 10 mW
Multipoint Support No
Maximum Paired Devices
Wireless Chipset
Transmitter Host Connection
Audio Connector to Source
Connector Plating
Adapter (Included)
Cable Design
Audio Connector to Earpiece
Cable Length
Cable Length
Cable Color
Cable Conductor Material
Battery Type
Battery Type
Battery Chemistry Lithium-Ion
Battery Chemistry
Capacity (mAh) 55 mAh (Left Earpiece)
55 mAh (Right Earpiece)
Runtime 7 Hours (BT)
Quick Charging Times 10 Minutes for 1 Hour
Recharge Time 1.5 Hours
DC Input Power 5 VDC at 650 mA
Wireless Charging
Charging Port Pins
Charging Cable Length 9.8" / 25 cm
Number of Channels
Users per System
I/O Connectors
Audio Decoding
Number of Charging Ports
AC/DC Power Adapter
AC Input Power
Power Consumption
Charging Case
Additional Runtime 13 Hours
Battery Chemistry Lithium-Ion
Capacity 420 mAh
Charging Time
Charging Interface USB Type-C
Platform Support
OS Compatibility
Required Hardware
Internet Connection
Charging Temperature
Operating Temperature 32 to 104°F / 0 to 40°C
Storage Temperature -13 to 158°F / -25 to 70°C
Operating Humidity 10 to 80%
Storage Humidity 10 to 90%
Water Resistance
IP Rating
LED Indicator
Material of Construction
Dimensions Headphones:
1.05 x 0.92 x 0.87" / 26.6 x 23.3 x 22.2 mm (Each)
Charging Case:
2.32 x 1.67 x 1.33" / 59 x 42.3 x 33.8 mm
Weight Headphones:
0.2 oz / 6 g (Each)
Charging Case:
1.3 oz / 37 g
Warranty Length Limited 2-Year Warranty