Answer:
•Wake up and charge the earbuds by placing them into the charging case and connecting the USB-C cable. Alternatively, after placing the earbuds into the charging case, press the button on the back of the charging case for at least 3 seconds.
•Select the correct ear adapter from a selection of four sizes (XS, S, M, L). Choose the ear adapter size that provides a very good seal in order to enjoy the best possible audio experience.
•Twist the earbuds slightly into your ear for perfect and secure fit.
•Pair the earbuds with your smartphone. The Bluetooth pairing mode is activated automatically once you first activate the earphones. Alternatively, you can manually activate pairing mode by pressing both touchpads for at least 3 seconds. In the Bluetooth menu of your smartphone, select "CX 400BT TW".
•A voice prompt will inform you once the pairing has been completed successfully.
•Download the Sennheiser Smart Control app from your app store to personalize your CX 400BT True Wireless experience.
•For further information and support, consult the supplied quick guide or online user manual, which can be downloaded from the Sennheiser website.
Answer:
The CX 400BT True Wireless has been created to provide exceptional sound performance, thanks to our 7 mm audiophile driver, the internal audio EQ and latest high-quality Bluetooth codecs.
However, to experience this sound to the full, it is essential to correctly place the earbuds in the ear-canal and to choose the best-fitting ear adapter set. The CX 400BT True Wireless comes with four sizes of ear adapters (XS, S, M, L) included in the box. The CX 400BT True Wireless quick guide explains precisely how to twist the earbuds into your ears to form a perfect seal within the ear-canal.
Please note that the sound may have been adjusted using the EQ function of the Smart Control app. To see if this is the case, connect to the Smart Control app and check the equalizer settings to ensure the desired sound.
Answer:
The specified battery time of 7 hours has been confirmed for music listening under the following conditions:
•CX 400BT True Wireless earbuds fully charged for at least 1.5 hours
•iPhone within 1-meter distance
•Bluetooth AAC codec
•Volume level set to 50%
•No customized EQ
The battery time may differ under different operating conditions.
Answer:
When using the Sennheiser Smart Control app, you will receive a notification once a new firmware release is available. The app will guide you through the update process. The firmware update will be installed over-the-air via the Bluetooth wireless connection.
Additionally, you can check for the current firmware release status in the Smart Control app's settings.
Answer:
The CX 400BT True Wireless has integrated power-saving features. When the earbuds are disconnected from a Bluetooth source and not in use, they will switch off automatically after 15 minutes.
To turn the earphones on again, press each touch pad for more than 2 seconds.
Answer:
Depending on the settings, your Mac uses the SBC Bluetooth codec by default. To know which codec is active, connect your CX 400BT True Wireless to your Mac and start music playback. Press and hold the option key and click the Bluetooth menu bar icon and navigate to the CX 400BT True Wireless entry (‘CX 400BT TW’). There you will see the type of codec used currently.
If you see SBC rather than aptX, then MacOS does let you change the codec via the “Terminal” app. Open Terminal and copy in this instruction:
sudo defaults write bluetoothaudiod "Enable AptX codec" -bool true
Should you prefer to use the AAC codec, just replace “aptx” with “aac” in the above instruction.
Please note that you will need to enter your admin login data to change these settings.