Audio-Technica ATH-M40x vs Sennheiser PXC 550

Sound signature is quite accurate, almost flat. Bass is much more controlled instead of boomy, while there is a slight elevation on the highs, resulting in extra energy and detail up top. These offer a nice middle ground between a fun sound and a more reference/analytical sound signature. This sound quality makes the headphones quite versatile as music enjoyment headphones or studio-use cans.

The M40xs feel solid and are known to be quite durable. The plastics used in the build do not easily flex or make creaks, giving the impression that these can last quite a long time.

The over-ear, closed back design along with the thick pleather ear pads can block out quite a lot of ambient noise, and will help users to focus in on the music. These make the headphones great for travel or for mixing/monitoring use.

The headphones come with a straight cable and a coiled cable, making them useful in the studio or while walking.

The feature works really well in preventing outside noise from intruding into your music listening experience. Also, there are very little to no reports of a feeling of pressure in the ears when the feature is active.

The sound tuning of these headphones is focused on the lower frequencies. The bass is quite powerful with good sub-bass extension. Users who listen to a lot of hip-hop, dance and bass-heavy music will certainly enjoy the oomph that these headphones can give. The mids sound natural and smooth, yet the lower regions of these frequencies can be overwhelmed by the powerful bass. The highs are crisp and clear though, which prevents the sound from getting too muddy.

Soft foam and leather are used in the interior and exterior of the ear pads respectively which makes them feel really soft and smooth on the head. The same material choices can be found in the headband.

The Smart Pause feature detects if you are removing or putting on your headphones. These gestures will trigger the music to pause or play automatically.

When in wireless mode, you do not need to use buttons in order to control the functions of the headphones. The right ear cup lets you control the headphones through touch gestures. You can swipe left or right for next or previous track, swipe up or down to increase or decrease the volume or tap on the ear cup to pause or play track as well as answer or end calls.

You can set just how much noise is cancelled by the headphones, from maximum active noise cancelling, to an ambient mode which allows some sound into the headphones. You can also turn the feature off entirely.

These headphones are quite effective at preventing sound leakage, and also passively block out noise really well. This is achieved by the closed ear cup design along with the effective seal from the leather-surfaced ear pads.

You can twist the ear cups and then fold them into the headband for a smaller, more travel friendly size. In this state, it should take up a lot less space inside your bag for less hassle when used on the go.

Sennheiser offers the CapTune smartphone app which allows users to see the battery level of the headphones, adjust the headphones' EQ, and control other functions.

The case is made from a tough fabric material which should protect the headphones from minor bumps and scratches.