Sennheiser MM 400

Bluetooth® stereo headset with built-in microphone and hands-free operation

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  • Sennheiser MM 400


  • Sennheiser MM 400

  • Sennheiser MM 400

Item #: 143MM400

Review Summary

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Original price $199.99
We recommend this similar item, or shop all All Headphones
  • Sennheiser MM 400-X
    • Sennheiser MM 400-X
      • The Sennheiser MM 400-X offers:
        • Bluetooth technology wirelessly transmits music and phone calls from your compatible portable player or cell phone to the headphones
        • advanced aptX audio circuitry for wirelessly streaming high-quality stereo sound from aptX-enabled devices
        • rechargeable battery and multi-country charger included
    • $269.99
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Our take on the Sennheiser MM 400

by Dave Bar

Going somewhere? Don't forget your Sennheiser MM 400 portable headphones. They're fantastic for enjoying your music and managing your phone calls without getting tangled up in cords. Built-in Bluetooth technology lets you make a hassle-free wireless connection to compatible devices, such as many cell phones, laptop computers, tablets, and MP3 players. You can even use the integrated volume, track skip, and call answer/end buttons on the right earcup for convenient operation while your phone or music player remains safely in your pocket, purse, or backpack.

Read more

Great comfort, sound, and convenience
The MM 400's soft padded ear cushions and adjustable headband provide a comfortable fit for hours of relaxed listening, making these 'phones great to have on long trips. The headset's folding design makes for easy storage when you travel. Sennheiser's patented Duofol™ diaphragms deliver detailed, crystal clear sound. And just in case you need it, Sennheiser includes a cable plus an airline adapter for a direct wired connection in situations where Bluetooth isn't permitted, or you want to make use of in-seat entertainment and other wired sound sources.

From the review Sennheiser MM 100 and MM 400 Bluetooth headsets: A family review of a headphone family

"I found the MM 400's light enough to wear for extended periods without any ear fatigue. The open-ear design gave the performance an airy, open feel..."

— Marshall, Crutchfield A/V Writer


  • portable, folding, on-the-ear design
  • padded, closed earcups and adjustable headband
  • Bluetooth® wireless operation
  • built-in microphone and wireless earcup controls for hands-free conversations using compatible Bluetooth cell phones
  • rechargeable lithium-polymer battery included
  • single battery charge gives you:
    • up to 20 hours Bluetooth talk time
    • up to 10 hours Bluetooth listening time
  • advanced Duofol™ drivers for outstanding sound quality
  • integrated controls on the right earcup for track, volume, and answer/end call functions
  • frequency response 15-22,000 Hz
  • 56" detachable audio cable with stereo mini plug included for wired listening options
  • airline adapter, USB charging cable, multi-country wall charging adapter, and carrying case included
  • weight: 3.7 oz.
  • warranty: 2 years
  • Our 60-day money-back guarantee

Hands-on research from the Crutchfield Labs (what are the Labs?)

Features and Specs
Fit Style On-ear
Earcup Type ---
Noise-canceling No
Bluetooth No
Frequency Response 15-22,000 Hz
Sensitivity 107 dB
Impedance N/A
Weight 3.7 ounces
Cord Length 56"
Airline Adapter Included Yes
iPod Control Yes
Volume Control Yes
Built-in Microphone Yes
Parts Warranty 2 Years
Labor Warranty 2 Years
Product Research
What's in the box?

Download owner's manual

  • Bluetooth portable wireless headphones
  • Lithium Polymer battery (installed/ 3.7 volt/ 1 Wh)
  • 56" Wired cable (2.5mm connector on one end and right-angle 3.5mm connector on other)
  • 48" Charging cable (USB type-A connector on one end and micro USB type-B on other)
  • Power supply adatper (5 volt DC/0.5 amp)
  • 4 AC plug inserts (US/ Europe/ UK/ Australia)
  • Airline adapter
  • Soft carrying case
  • Quick Guide
  • Animated manual CD-ROM

Our Product Research Team

At Crutchfield, you'll get detailed, accurate information that's hard to find elsewhere. That's because we have our own in-house Product Research team — they open the box, verify contents, check the owner's manual, and record dimensions, features and specs. We stay on top of new products and technologies to help people make informed choices.


Bluetooth Wireless Reception/Transmission: The Sennheiser MM 400 features Bluetooth v2.1 wireless reception and transmission with a built-in microphone for cable-free use with select Bluetooth enabled phones and audio devices. Supported Bluetooth profiles include A2DP (Advanced Audio Distribution Profile), AVRCP (Audio/Video Remote Control Profile), HSP (HeadSet Profile), and HFP (Hands-Free Profile).

Note: Not all Bluetooth enabled audio devices will be compatible.

Controls: On the right ear-cup there are integrated controls for your connected phone or audio device. Audio controls include volume, skip forward or backward, fast forward or rewind within a song, pause, play, and stop. Phone controls include volume, accept call, reject call, end call, redial, voice dial, and mute.

Note: All control functions must also be supported by the connected device. The 2nd generation iPod touch, iPhone 3G, and iPhone 3GS support only the play, stop, and pause audio functions via AVRCP.

Battery Pack: The MM 400 has a removable Lithium-Polymer battery pack (3.7 volts DC/1.0 Wh) which provides up to ten hours of music playback or up to 20 hours talk time (phone). An AC adapter is included to charge the battery pack; charging time is approximately three hours. The headphones can also be charged using a computer's USB port.

Collapsible Design: These headphones feature a collapsible design with metal-reinforced headband to ensure portability and durability.

Cord & Adapter: The MM 400 will also work as wired headphones, useful when Bluetooth connection is not an option. The headphones come with a 56" mini-jack cable terminated by a 3.5mm connector for a wired connection. An in-flight audio adapter (dual mono 3.5mm) is included for added travel convenience.

Carrying Case: A nylon carrying case is included to protect the headphones during storage or transport.


Product reviews from the Crutchfield Labs (what are the Labs?)

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Sennheiser MM 400 Reviews

Average Customer Review:

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3 out of 5

Sennheiser MM 400

Written By Anonymous, usa on Sunday, February 12, 2012
the sonud is very good but the ear cover are to small
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4 out of 5

Handy Headset

Written By Jonathan S, Greenwich CT on Sunday, January 29, 2012
Crutchfield Customer Review (What's this?)
The Sennheiser MM400 bluetooth headset is a convenient way to connect to my I-Phone, or I-Pod or I-Pad. It is light weight, compact, and easy to use. The over the ear design lets you hear ambient sounds and conversations, and makes it easy to answer the phone with a tap on its switch on the right ear.
Compact, light weight, comfortable
For first time use, it was not totally intuitive how to synch up. Graphic multi lingulal instructions are not my thing.
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For a more in-depth review and enhanced detailed information on the Sennheiser MM 400, please visit the Crutchfield website product page (/ISEO-rccbcspd/p_143MM400/Sennheiser-MM-400.html ).