In-ear headphones Sennheiser CX 400-II black — wired earphones with noise isolation

Sennheiser CX 400-II black are wired in-ear headphones designed for personal audio listening with passive noise isolation. The compact form and ergonomic ear tips provide a snug fit for everyday use, commuting and casual music listening. The model emphasizes clear sound reproduction across frequencies and practical portability, making it suitable for users who need reliable wired earphones with focused audio performance and minimal external noise intrusion.

Advantages

These in-ear earphones combine Sennheiser acoustic tuning with a compact wired design, delivering defined mids and highs and balanced bass for a wide range of music genres. The passive noise isolation relies on interchangeable silicone ear tips to reduce ambient sounds without requiring active electronics. The compact housing and braided cable enhance durability and portability while maintaining a straightforward plug-and-play connection for devices with a compatible audio jack or adapter.

Suitable for

• Daily commuting and urban travel
• Casual music listening at home or outdoors
• Phone calls and voice communication with compatible devices
• Portable use with laptops, tablets and music players

Key specifications

• Form factor: in-ear, wired
• Noise control: passive isolation via snug silicone ear tips
• Sound signature: balanced tuning with clear mids and highs
• Cable: durable, tangle-resistant design with 3.5 mm connector compatibility
• Fit: ergonomic compact housings with multiple ear tip sizes included

How to use

Select the silicone ear tips that provide the best seal for your ear canal and attach them securely to the earphone nozzles. Insert each earphone gently into the ear and adjust until you feel a comfortable, snug fit that provides passive noise isolation. Connect the 3.5 mm plug to a compatible device or use an appropriate adapter if needed. Control playback and calls using the connected device or inline remote if present on your specific cable variant.

Recommendations

To maintain sound quality and fit, clean the ear tips regularly and replace them if they show signs of wear. Store the earphones in a protective case when not in use to prevent cable damage and to keep the housings free from dust. For best passive noise isolation, try different tip sizes to find the optimal seal for your ears.