Audio-Technica ATH-M40x vs Bose QuietComfort 25

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 traveling case is small and provides room for spare batteries and other components. This makes it pretty portable, for those that can't or don't want to leave their headphones at work.

These headphones use a triple-A battery to power noise canceling. Should it run out of charge, it can easily be replaced.

With the feature switched on, you can really zone in on the music. Noise canceling is very effective at blocking out ambient noise, especially the lower frequencies. On a flight for example, engine noise is drastically reduced, as well as most of the sound from the conversations in your vicinity.

The QC25 feels comfortable even after wearing it for several hours. The pads go over the ear and feel soft, as the ample cushioning is covered with supple and high quality synthetic leather. Aside from the usual headband padding, it also has an inner Alcantara lining that feels really nice on the skin.

You have a number of options as to how you want to use these headphones' active noise canceling feature. You can either have the feature on or off while you are listening to music, or have noise canceling on without audio. This is a nifty feature if you just want to enjoy some peace and quiet when in a noisy place.

These headphones will not tire your head or neck out, even if you wear them for quite some time. These are pretty light at around 196 grams.

Sub-bass is a bit laid back, but the overall low-end production is punchy and with good extension. Mids are clear and forward so vocals, guitars and keys sound good with these. The upper treble is boosted, which results in good detail, but can also give harshness to the sound.
Overall, this is a really fun set of cans to listen to, especially if you just want to have a fun music listening experience.