"Bose QuietComfort 15 / 25 / 35" vs "Sennheiser MM 550-X TRAVEL" (noise cancellation headphones)

On short
QC25, QC15, MM 550-X
  • Bose Quiet Comfort (QC) 15 / 25 / 35 have superior noise cancellation and are slightly more comfortable.
  • Sennheiser MM 550-X have Bluetooth connectivity and a more "audiophile" sound. Update: QC35 also has Bluetooth.
These are rather old products, however they are still very competitive in their class. I used Bose QC15 and Sennheiser MM 550-X more than 2 months and I would like to share with you my personal (subjective) opinions about them. I also tried Bose QC25 for a short period, it is the improved version of QC15, allowing listening also without battery and has slightly better folding.

I will detail my experience in relation with three use cases where these headphones could be a match. But before this, check this small introduction on noise cancellation, to see why you cannot expect miracles from it.

Update 2017 on QC35: I had the chance to also test and buy the newest Bose Quiet Confort 35. They are similar with QC 25 but with Bluetooth connectivity. The Bluetooth connection is superior to MM 550-X as you can seamlessly move from phone to laptop and back without stopping the other (only 2 connections are kept). Basically, you just stop the music on one side and start it on the other. QC35 might be a little heavier that QC25, but they are still very comfortable. As QC25 (not QC15), they can also operate without battery, however the sound might not be very powerful on some audio sources. 

Actually QC35 is using an internal rechargeable battery (not replaceable), however I could go 3 full work days listening over Bluetooth without recharge. The controls are very intuitive and simple, you don't need to keep a button many seconds for start/stop the headphones or pairing. The charging plus is easily accessible using regular micro-USB cables. You also have audio information about battery level. The notifications about connected sources could be a little too verbose, but audio voices can be disabled from the Android app (some beeps remains instead). They should support streaming audio to a second Bose QC 35 (not other headphone types) but I could not test it: for example 2 people might want to listen wireless from one Bluetooth source, like TV.

Bose QC 35 does not support the "slightly better?" AptX propietary codec, however the sound is good enough as A2DP is (think mp3 128kbps). The microphone quality is good for audio conference, however the audio listening will switch to lower/mono quality as MM 550 also does. Note that wind might make them sound funny sometimes. There are some clicks and glitches sometimes when you commute between 2 audio sources.

Overall they are great headphones, just that they are kind of expensive, I waited months to buy them with discount, at 300Euro. The best usage for QC 35 is to work in open-space without being disturbed by not very loud discussions and noises around. You can also keep the music volume at very low levels. For telecommuting it also works very fine, however it's harder in the winter if you cover your head and if you want to protect them from water.

Purpose match

For simplicity, I will use Bose and Sennheiser for "Bose Quiet Comfort 15 / 25" and "Sennheiser MM 550-X" respectively. When there is a difference between Bose QC15 and QC25, I will specify the exact model.

1. Travel headphones

Both headphones are designed for travel.  They are "over ear" and this provides a first level of noise isolation - better than usual headphones, however you will pay premium for the active noise cancellation feature ;)

Their main target seems to be the people that are traveling by airplane, or train. They both can be folded for easy packing, they have nice cases. Bose might be a little more compact than Sennheiser. You you want even more compact ones you can check Sennheiser MM 400-X, that have the same features with 550-X but are over year and incredibly compact. The sound is almost the same, but it might not isolate the same as "over ear" ones.

Both have microphones for taking calls. Bose has the microphone on one of the cables (the other is only for listening), while Sennheiser has invisible microphones on the headphones. Both provides good microphone sound. I suspect that Sennheiser combines the sound from the 2 microphones on sides, because they are relatively far from my mouth but my voice was understood even in very loud noise.

Both have controls for pausing the music (for Bose on the microphone cable). Sennheiser has volume controls on the headphones that are working while having battery (on Bluetooth of cable). Bose QC15 has also a volume control on cable, however it does not work on my phone (Nexus 5). Sennheiser on Bluetooth has buttons to do Next/Previous on the player. Bose might work too but I could not test it.

Bose is a little more comfortable than Sennheiser, despite the fact that they have almost the same shape and material. Sennheiser is just couple of millimeters smaller and makes my ears to not fit perfectly. However, Sennheiser is still more comfortable than other headphones that I tried.

Sennheiser has the main advantage that you can can also use them without wires, via Bluetooth. Of course, you need a Bluetooth enabled player, like a smartphone. The Bluetooth quality is unexpectedly good. You need a quiet room to notice the difference from wired, even with the default A2DP/SBC codec. If the transmitter supports the proprietary A2DP/AptX codec, the quality can be even better. However I did not noticed the difference with my AptX transmitter connected to my non-AptX phone. For travel, the quality should just great.

Of course, if the battery is depleted, Bluetooth cannot work, the same for noise cancellation. Actually, Bose QC15 does not work at all without battery, while the newer QC25 can be used without battery. One advantage of Bose (QC15/QC25) is that you can easily replace the battery with a standard AAA or a rechargeable AAA. Sennheiser uses a proprietary battery charged over USB. It is replaceable, so you can buy another as "charged spare", but it adds to price. You can charge Sennheiser with any micro-USB charger like the smartphone, however not any cable will fit because of the battery margins. On the other side, Sennheiser can be used without battery (by cable), while Bose QC15 cannot (the newer QC25 can). On cable, Sennheiser might not sound loud enough with some players. QC25 sounds just a little less loud without battery.

Update: to be honest, I still cannot blindly tell for Sennheiser 550-X when the noise cancellation is on or off, even if I switch the button. There are differences in sound, but the difference is really minor. I have to check the lighting on the button in order to clearly identify the "on" setting.

Sennheiser has a "pass through" button, so you can better hear people talking without removing the headphones. This might be handy sometimes.

2. Work headphones
Both Bose and Sennheiser have active noise cancellation, however Bose does it significantly better. The only advantage for Sennheiser here is that you can get rid of the wires by using Bluetooth. Wireless might be even more important at work than on travel, because it allows you to walk around while in an audio conference. While on a plane or train, the wires are not such a big deal usually.

Noise cancellation does not totally cancel loud office noises and voices, however it does help for sure. While voice cannot be canceled because it is an unpredictable sound, the combination between good passive isolation and some floor static noise from the noise cancellation makes the moderate discussions at couple of meters away to not be discriminated anymore, removing the distraction of hearing fragments of phrases.

You can actually get more noise reduction using industrial noise isolation earmuffs (like "3M"). The thing with noise cancellation headphone is that you can get reasonable noise reduction with comfortable ear cups that don't makes your head hurt after 30 minutes. On noise cancellation headphones you can also listen you favorite music. Because of noise cancellation, you don't need to put the volume very high to cover all the noise around, you can actually listen at a lower volume than on regular headphones.

I would say that Bose cups are a little more comfortable than Sennheiser, while they are both very comfortable. They both cover the ear very well, while other headphones leave space between cups and head. Many other circumaural "around the ear" headphones that I tried are still touching the ear with the hard material protecting the drivers. This is not happening with the Bose and Sennheiser above.

3. Music listening
These 2 headphones are not designed for audiophile music listening. However, they provide very good music quality compared with regular phones. The frequency response is very good, they don't "miss" some frequencies. On heavy bass they don't go into unpleasant vibrations.

While using noise cancellation, both will have a small floor noise as an artifact of noise cancellation. This is not noticeable most of the time, except when it is really quiet. It you are picky about this you should not use noise cancellation...

On QC15 you cannot stop noise cancellation. On QC25 you can also use the headphones passively. However, the sound is less great than using battery.

Sennheiser can be used also on wires, with or without internal amplification. When using the internal amplification, the buzzing/static noise is even more disturbing than on Bluetooth, I would not recommend it. However, when using them passively the sound is just great, crisp and clear, with no noise at all. They sound very open for a pair of closed headphones. They are not too "bassy", not too "on the treble side", they have just a plain, balanced response. I would say they sound better than my Grado SR60i open phones. While you can find same audio quality at lower price, you get this on top of  Bluetooth portability and a some noise cancellation.

One annoying thing on Sennheiser was the flashing blue LED that  was visible on the side while listening. Fortunately, you can disable the blue LED flashing on Sennheiser MM500-X by putting it in pairing mode (Off -> long press middle button until flashing red and blue - around 10 seconds), then press "volume down" once. You can re-enable LED blue light flash on MM500-X by putting in in pairing mode and pressing "volume up".

Final evaluation:

1. Travel: despite the advantages of Bluetooth wireless usage in Sennheiser, I would say that Bose is a little more suitable for long travels, because of the comfortable cups, cheap battery spares and superior noise cancellation.
2. Work: I would call it an "even" here, because the better cups comfort and better noise cancellation in Bose balances with the possibility to take wire-free meetings with Sennheiser.
3. Music listening: for people searching for a sound as close to "audiophile" as possible, Sennheiser should be the winner, when used with cable and without amplification. It is debatable if Bluetooth in Sennheiser still sound better than wired Bose, but getting rid of the wires could be a real advantage for some people.

Update 2016-07-25:
The only major advantage of Sennheiser MM 550-X over Bose QC15/QC25 was the Bluetooth. Now Bose also has Bluetooth with QC35. From my limited tests, if I would have to chose now, I would fully go with Bose QC35 over Sennheiser MM 550-X for any of the 3 above usages. They are very expensive however.

Bose QC35
For an "audiophile" sound, I would go for separate (maybe open) wired headphones. This is because such portable headphones (both Sennheiser and Bose) are not optimized for usage without battery so they require a very powerful signal. The internal amplifier is not audiophile grade, when there is silence around, you will still hear some while/static noise if you listen carefully - on any of them.

P.S. I don't receive any material advantages for this review, I just hope it will be of help.


  1. Thank you very for your effort. I appreciate your post.

  2. Grazie mille per l'articolo davvero molto molto interessante.

  3. Just the kind of review I was looking for.
    Bose for the win, expensive though.
    Thank You

  4. This comment has been removed by a blog administrator.