Sennheiser MM 550-X TRAVEL - MM550-X

Premium Over-Ear Noise-Canceling Bluetooth Headset


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General Features:

  • Wireless Bluetooth Noise Cancelling Over-Ear Headphones
  • Designed with your traveler lifestyle in mind
  • Wireless Bluetooth Technology provides completely cable free enjoyment for truly portable usage
  • NoiseGard 2.0 Noise-Cancelling technology provides up to 90% Active Noise Cancellation
  • SRS WOW HD Delivers Incredible Simulated Surround Sound for 3D like Imagery and added depth
  • Integrated Microphone with adjustable Volume Controls for use with iPhone, Android, Blackberry and Windows Smartphones
  • Adjustable headband for comfortable listening sessions
  • Replaceable Long Life battery allows recharging via USB port or wall adapter
  • DuoFol transducers deliver high-fidelity audio
  • Includes Airplane/Airline Adapter for convenient travel
  • Soft, Luxurious Noise Isolating Ear Pads/Cushions (Model 531404)
  • Primary Color: Black
  • LED Color: Blue
  • Manufacturer Model Number: MM 450-X TRAVEL
  • Manufacturer Part Number: 504515
  • Sennheiser MM TRAVEL Series Bluetooth Noise-Cancelling Headphones Are Available In:
  • Authorized Internet Dealer
  • 1-year Manufacturer's Warranty

Product Specifications:

  • Speaker Type: Dynamic Driver
  • Magnet Type: Neodymium
  • Frequency Response: 15 Hz - 22,000 Hz
  • Nominal Impedance:
    • Active Mode: 590 Ω
    • Passive Mode: 100 Ω
  • Sensitivity: 107 dB
  • THD (1 kHz): < 0.1%
  • Bluetooth:
    • Version: 2.1 + EDR
    • Range: Up to 33 ft
    • Transmission Frequency: 2.4 GHz
    • Transmission Power: 8 dBm
    • Profiles: HSP, HFP, A2DP, AVRCP
    • Codec: SBC, apt-X
  • Power:
    • Supply: BA 370 PX Rechargeable Battery (BA370 PX)
    • Battery Type: Lithium-Polymer
    • Charge Time: 3 Hours
    • Playback Time:
      • Talk Time with NoiseGard 2.0: Up to 20 Hours
      • Listening Time without NoiseGard 2.0: Up to 10 Hours
      • Listening Time with NoiseGard 2.0: Up to 8 Hours
  • Cable (531406):
    • Detachable: Yes
  • Plug Size: 2.5mm to 3.5mm

What's in the Box?

  • Sennheiser MM 550-X TRAVEL Bluetooth headset
  • BA370 PX Rechargeable Battery
  • USB Cable
  • AC Power Plug
  • U.S., European, U.K., Australian Power Adapters
  • Audio Adapter Cable (531406)
  • Airline Adapter (1x Female 3.5mm to 2x male 3.5mm)
  • 1/4" Adapter (6.3mm)
  • Zippered Travel Case
  • Instruction Manual on CD-ROM
  • User Guide
  • Authorized 2-Year Warranty

Also found as: MM 550X, MM-550X, MM550X, Sennheiser MM 550-X Flight, MM550-X, Sennheiser 504515

Product History:

Sennheiser MM 550-X thumbnail
(newest, current model)
Sennheiser MM 500-X thumbnail
(previous model, replaced by Sennheiser MM 550-X TRAVEL - MM550-X)

Headphone Design

Headphone Type

This is the design of the earpieces on the headphones. Some headphones go inside the ear, while others rest on the outside of the ear. This helps you know exactly what type of headphones you will be receiving.

In-Ear: The ear buds go into the ear. Most often, the right and left ear buds are two separate pieces.

Enclosed-Ear: Usually are found on the larger headphones. They rest on top of the ear and have padding for comfort, as well as enclosing the ear to the speaker. This type of headphone helps to filter out surrounding noise.

On-Ear: This type of headphone involves the speaker sitting gently on the ear without going in the ear or sealing it off.

Headband Type

Headphone type refers to the construction of the headphones.

Around the Ear means that the headphones wrap around the ear to provide a secure fit. This is most often seen in active and sports headphones.

Around the Neck means that the headphones wrap around the neck. This is also seen in active and sports headphones.

Earbuds means that the right and left sides of the headphones are separated and will fit securely into the ear. These are small, compact, and user friendly.

Over the Head headphones mean that the right and left speakers are connected with a support that goes over the head and rests on top. This is the typical headphone type.

Over the Head
Specifically For
Some headphones can use an IR Transmitter in your vehicle, while some can be plugged into your media device and be used on the go or at home.
Headphone Application

This is the application that the headphones are designed for. Each application has unique features that make it perfect for particular uses.

DJ: These headphones are durable, loud, and will often allow for one ear listening.

Gaming Delivers explosive sound and allows you to communicate with others.

Home Hi-Fi: These audiophile headphones are engineered to produce high fidelity and accurate audio.

Home/Office: These headphones are designed to produce rich, brilliant sounds that the artists would appreciate.

Sports: Designed for active use. These headphones are made to stay in (or on) the ear during workouts.

Kids: Feature noise limiting technology so that your little ones don't damage their ears listening to music too loud.

On-the-Go: On-the-go headphones are lightweight and often fold up for easy storage and portability.

Student: Compact and rugged enough to survive life in a backpack; inexpensive enough to not hurt the wallet of a student.

Studio: Reproduce music perfectly without any coloration. Look here for reference quality studio monitoring headphones.

Traveler/Airplane: These headphones are compact, lightweight, and have a portable design.

Acoustic Principle

The basic design of the headphones. There are 3 different types:

Open: Have ports that allow air through the back of the diaphragms, enabling the headphones to sound like the music is coming from an outside source.

Closed: Completely sealed and have no air passing through the diaphragms. Sounds like you are in a closed off room.

Semi-open: Have slots or ports in the back of the cup and are partially open. This allows for a mixed sound between an open and closed headphone.


General Features

Noise Reduction technology removes unwanted noise from a signal. Background or ambient noise can be removed to produce clearer speech and enhanced hearing. Typically these Active Noise Canceling (ANC) headphones are powered and use batteries to activate the noise canceling technology. Also referred to as Noise Reduction or Noise Cancellation.
Device Controls & Compatibility
Refers to the devices the in-line controls are compatible with.
Universal Volume
Built-In Microphone
This means that the headphones or earbuds have a built-in microphone. This can be a microphone on the cord, built into the headphone, or even a boom microphone. These mics can be used for music devices like iPods, for Smartphones to make and receive calls, or for gaming purposes.
Built-in to Earpiece
Headphone Connection
This is how the headphones connect to the audio source.

Corded means that the headphones use a cord to transfer the audio signal.

Bluetooth means that the audio signal is transmitted from your device to the headphones via a Bluetooth connection.

Corded or Bluetooth means that the headphones can be used as corded headphones or as Bluetooth headphones. They have an input in one or both earcups for use as a corded headphone while they also have a built-in battery for use as Bluetooth wireless headphones.

Wireless means that the audio signal is transmitted wirelessly to the headphones.

Bluetooth Wireless
Volume Adjustment
Volume Adjustment means that the headphone (independent of the source) can adjust the playback volume. Many headphones and ear buds have in-line volume control, which allows adjusting the audible volume from a switch on the headphones cord. Other headphones have a volume knob on the headphone can.
Connector Type
The type of connection the headphones use to connect to receive the audio signal from a music source. Traditional headphones use an analog 3.5mm headphone jack. Newer technology has allowed digital signals to be sent directly to the headphone using an Apple Lightning or USB-C cable.
Jack Size
Refers to whether the headphones use a 3.5mm or 1/4" headphone jack connection.
Jack Angle

The Jack Angle refers to the angle of the input jack on the headphone cable.

Straight Jack: Straight plug with no angle.

Angled Jack: Angled plug, usually a 90 degree angle.

Swivel Jack: A swivel jack is able to swivel between a straight plug and an angled plug.

Straight Jack
Included Adapters
Refers to the connection adapters included with the headphones like 3.5mm or 1/4" input adapter as well as airplane adapters that let you use your headphones with airplane specific headphone jacks.
1/4" Adapter
Airplane Adapter
Color Shades
Primary color shades of the headphones.
Refers to materials used to build the headphones. Most headphones are built from some combination of plastic and metal to give you a durable pair of headphones.
Ear Cushion/Earbud Material
Refers to the material that the ear cushions/earbuds are made from. Ear cushions and earbuds are available in a variety of materials, ranging from basic rubber eartips to plush leather ear cushions intended for maximum comfort.
Protective Case
Refers to whether a pair of headphones come with a protective case.
Softshell Case
Water Resistant
This refers to the level of water resistance of the fitness tracker. Some fitness trackers are water resistant and can be used while swimming, while others are only splash proof or should not be used near the water.
Refers to whether a pair of headphones can be folded up. These headphones feature hinges in the frame above the earcups that allow the headphones to neatly fold into a much more manageable size. Folding headphones are perfect for anyone who spends a lot of time traveling and needs a compact pair of headphones that can fit in their bags.

Audio Features

Driver Type

The physical design of the driver in the headphones.

Balanced Armature:
A balanced armature driver uses a coil wrapped around an armature which is held in between two magnets until it is stimulated by an electrical current. When stimulated, this armature is magnetized which causes it to rotate one way or the other around a pivot point which moves the diaphragm to create sound. Balanced armature driver headphones are generally earbuds and can have multiple drivers in each earbud.

Dynamic drivers are the most common driver type. They feature a permanent magnet, usually neodymium, a voice coil and a conical diaphragm to drive your music. A dynamic headphone driver looks pretty much identical to any typical home theater speaker.

Electrostatic drivers are made up of an extremely thin membrane, usually a coated PET film, stretched between two metal plates. An electrical signal is applied to the metal plates to create an electrical field which, depending on its polarity, draws the speaker diaphragm toward one of the plates which forces air through the perforations in the diaphragm which generates the sound wave.

Planar Magnetic:
A planar magnetic driver is made up of a large membrane suspended between two sets of oppositely aligned magnets. An electric charge is applied to the membrane to induce movement and produce sound waves.

The opposition to electric current, a higher impedance means a higher electrical resistance. This is measured in ohms.
16 ohms
Frequency Response
The range of frequencies the speaker will reproduce (lowest frequency to the highest). Bigger is better, meaning the wider the range, the better. The optimal range is 20 - 20,000 Hz (which is the range of human hearing).
15 - 22000 Hz
Audiophile headphones represent some of the finest headphones available. Audiophile headphones produce genuinely outstanding sound quality as well as extraordinary build quality, components and comfort. They are truly the finest headphones available.
Built-in Amplifier
This refers to whether the headphones have an amplifier built-in.

What is in the Box?

Main Product
The main product in the box.
Sennheiser MM 550-X TRAVEL Headphones
Accessories included with the headphones
1/4" Adapter
Airplane Adapter
Carrying Case
Charging Cable
Power Adapters
Secondary Cable
Paperwork included with the product.
User manual
Warranty/Registration card

Warranty and Return Policy

Parts Warranty Duration
1 year
Labor Warranty Duration
1 year
Warranty Provider

Summary of Customer Ratings & Reviews

Rating Distribution

5 Star
4 Star
3 Star
2 Star
1 Star

Average Attribution Rating


Walker La

Great cans

September 30, 2014

Very good sounding cans. Taking a plane ride this weekend want to see how the noise canceling works. Tried them on noise canceling on my mower, 32hp deisel zero turn. Helped some. I think I was asking to much of them.
As ben stated before the volume is a litte low. iPhone 5 will drive them.
The base is clean as is the highs.
I would not hesate to recommend to a Frend.

37 of 45 found this helpful

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More than expected

September 27, 2014

1. Customer Service: starting from the very beginning, there had been some doubt about this website- not well known to me and my friends. I called their 877 number. A gentleman helped me made my decision: he is straight forward, honest, and willing to do something to give me a deal.
2. shipping: delivered as promised - Friday, so i did have the weekend to enjoy this big buck purchase.
3. personal feeling to this headphone: crisp clear voice, gives a new level of experience to audio. It feels like i can carry my home 5.1 audio system with me all the time, on the bus, in the backyard, and at work.
4. speaking of work, i sit in front of desk 5 days/week, 9 hours/day. This one does help go through the boring workload. By the end of the day, my ear drums are still ok - not like other ones I have, they made me feel so tired. The downside is that, the battery. I wish I bought a spare together with it. Now, I had to pay international shipping again to get it from this website.
5. had a couple friends who work in recording business and as musician. they say this is a true piece of reward to the ears.
6.noise concelling is not supper: low frequncy part is ok, not on the human voice. to me, this is good enough.
Over all, happy with the product and the service from here. plan to buy another one as Christmas gift for my wife- such a beatiful thing, she deserves it.

35 of 45 found this helpful

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Geneva , IL

Sennheiser MM550x Headphonse

July 15, 2015

I researched a good number of high end bluetooth, wireless headphones before selecting the 550x. The 2 year warranty, great sound quality, portability and feature rich components sold me despite the somewhat non contemporary style. I decided to be a leader and not a fashion trend follower in that regard. Quality is evident and that's that !

12 of 15 found this helpful

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Browse 3 questions and 4 answers
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Why did you choose this?
Sonic Electronix Store
seinnheiser produces great sounds. the headphone is great for traveling
Michelle C on Oct 11, 2015
Sennheiser makes a good set of cans.This is my 2nd pair.
I bought these for over the ear, noise cansulation feature and bluetooth.
I have a diesel lawn mower and tractor and want to see if they will counteract the noise level. A LOT TO ASK FOR!!
Wayne L on Aug 16, 2014
combination of highest quality sound and features. By far lightest weight of the high end headphones.
Timothy S on Nov 7, 2014
Is this the latest version of the 550 MM-x Travel? Does it have bluetooth 2.1?
frank f on Sep 5, 2015
Best Answer: As far as I know,, this unit which I purchased Nov 2014, is still the most current. And if it is not, I cannot imagine any additional features on a newer release that are not already in this unit. I have an iPhone 6 and an old Anker BT transmitter, which span all the BT versions, and the MMX pairs consistently with everything. The case is very useful, and the whole ensemble fits easily into a small messenger bag, including the extra battery and direct audio cord. Finally, unlike many (higher end) phones, this performs well with no battery and a direct (standard) audio cable, (3.5mm-2.5mm). Finally, significantly lighter than most others most others.
Reply · Report · Timothy S on Sep 6, 2015
· Add Answer · I Have This Question Too (0)
For the reviewer who bought this product from Ontario in Canada, can you advise how much the shipping, and especially any customs duties/fees, were? Thanks.
taylor1950 on Apr 9, 2015
· Add Answer · I Have This Question Too (0)

Product Summary


Model Number

MM 550-X





Internal SKU


Internal Product ID


Sonic Electronix Wiring Guide

Wiring Diagram Legend

Warning: The image depicted shows the resistance change when wiring multiple subwoofer terminals. Please refer to your subwoofer's owner's manual for the proper wiring of its terminals. Sonic Electronix, Inc. is not responsible for damage caused to your audio system or vehicle due to improper installation. Please call tech support at 1-877-289-7664 if you require additional assistance.

Product Name: Sennheiser MM 550-X TRAVEL - MM550-X

Item Added to Cart

Sennheiser MM 550-X TRAVEL - MM550-X

Premium Over-Ear Noise-Canceling Bluetooth Headset


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