Sennheiser PXC 550
The PXC 550 is, together with the Sony MDR-1000X, the most expensive pair of headphones in this test. This does set a certain level of expectations, that the device definitely meets in terms of comfort. It looks a bit rougher than the Bose, but it weight about the same. The Bose has much larger earcups, which makes putting on the headphones easier. Nevertheless the Sennheisers are also very comfortable once they're on your head, even when used for a long period of time.
There are two connections on the right earcup - 3.5mm and micro USB - and three buttons. The switch button allows you to enable noise cancellation, in two step, with the button next to it you can choose an audio preset (film, club or speech) or disable this feature. There's also a well-hidden button on top that is used to enable or disable Bluetooth. This means that this is one of the devices with a separate button for Bluetooth and noise cancellation. The volume is controlled by moving your finger up or down on the cup, like on the Zik 3. The downside to this is that you can't change the volume if you're out of power, unless you do it on your source.
Sennheiser also has an app, that doesn't work when the headphones are connected through a 3.5mm jack, just like all other models in this test. You'll need to use a Bluetooth connection in the case of the PXC 550. The app features a very minimalistic design. You can set the level of noise cancellation and apply some equalizer settings.
The sound quality of the PXC 550 is definitely the best in this test, which was to be expected given the price. Mainly the detail and separation between the various frequencies is very good. Both the highs and lows are nice and audible, which cannot be said of all models in this test. There's also only a small difference in terms of sound quality with noise cancellation on. This is quite rare, but very nice indeed. The noise cancellation works very well, it's on a similar level as the Bose headphones.