Sennheiser MM 400-X
Collapsible Bluetooth Headset


Our Price: $269.95
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Sennheiser's MM 400-X is a state-of-the-art Stereo Bluetooth headset for multimedia-capable mobile phones, now supporting the hi-fi Apt-X codec.

With one press of a button, you can quickly switch between calls and music delivered in superb stereo sound.  The invisible high-performance microphone ensures that conversations are clear, making this headset the perfect all-in-one sound solution for your digital lifestyle.

Using a closed, on-the-ear design to block ambient noise, the MM 400 is an ideal companion for the urban commute or frequent traveller.  Advanced DuoFol transducers provide the kind of detail and frequency response you would expect out of hi-fidelity audiophile speakers.  The easy-to-use control panel is intuitive and simple enough to operate with your eyes closed.

The MM 400-X folds up for the ultimate in portability.  The replaceable battery charges via USB or a wall adapter.  For situations where Bluetooth is not permitted, you can use the included audio cable for a direct connection- making the MM 400-X an extremely capable wired headphone as well.


  • New iPad and tablet compatible for streaming music
  • Wireless freedom with Stereo A2DP Bluetooth®--hands-free convenience and hi-fi stereo sound on Apt-X capable audio sources
  • Discrete, invisible microphone is always out of theway
  • Direct cable option – listen as a wired headphonewhen Bluetooth is not permitted
  • Android, iPhone/iPod/iPad compatible, compatible withall 1/8" (3.5mm) headphone plugs
  • Easy-to-use controls are within optimum reach andprovide concise "click" feedback
  • World-famous Sennheiser acoustics from patentedDuoFol transducer system
  • Plush ear cushions seal out ambient noise whilemaintaining luxurious comfort for hours on-end.
  • Collapsible headset stores in a compact footprint forconvenient portability
  • Replaceable battery charges via USB port or suppliedwall adapter
  • Connect everywhere – to mobiles, laptops, MP3players, or in-flight entertainment systems with an all-in-one headsetsolution
  • Built-tough with a 2-year international warranty

*Due to the nature of Bluetooth technology, users may experience a slight audio latency when watching video on a portable device. The headphones are working fine. This is a characteristic of all Bluetooth headsets. Latency is not an issue for audio-only use, OR when using the included detachable headphone cable for a wired audio connection when watching video.


  • MM 400-X headset
  • Audio cable with in-flight adapter (3.5mm double monoadapter) (part # 531406)
  • USB cable (part # 531407)
  • Wall charging adapter (part # 525776)
  • Carrying case
  • Battery (pre-installed, part # 535105)
  • Ear cushions (pre-installed, part # 531404)


  • EAN code: 4044155077841
  • Package Dimensions: 7.5" x 3.3" x 7.9"
  • Package Weight: 1.9 lbs
  • Wearing style: On-the-ear
  • Transducer Principle: Sealed (closed)
  • Bluetooth Technology: 2.1+EDR and Apt-X
  • Talk Time: Up to 20 hours
  • Listening Time: Up to 10 hours
  • Charging Time: Approximately 3 hours
  • Range: Up to 33 feet
  • Weight: 3.7 oz (105 g)
  • Frequency response (headphone): 15 Hz - 22 kHz
  • Total harmonic distortion: <0.1% (1 kHz)
  • Sound Pressure Level (SPL): Up to 107 dB
  • Frequency response (microphone): 100 Hz -10 kHz
  • Microphone pickup pattern: Omnidirectional
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