Koss PortaPro vs Sennheiser PXC 550

The drivers may be small and thin, but there is good bass presence.. The mid-range may not be the most detailed, but there is a smoothness to it that gives the sound a warm and pleasing quality. There is a slight roll-off to the high frequencies yet detail and extension is still good . Overall, these headphones can give a fun listening experience that can work well with all genres of music.

Koss provides a lifetime warranty for these headphones.

The ear cups can be folded into the headband. This further reduces its already slim design into something that is much more compact. When folded down, these headphones can easily fit in small bags.

The headband can easily be adjusted to fit a user's head. The assembly features sliding metal pieces which can easily be set to fit small to large heads.

Aside from headband adjustment, users can also adjust the clamping force of the ear cups using the Comfort Zone system. This changes how secure the ear cups attach to the headband, which results in either a loose or tight clamp.

These are eye-catching headphones because of their retro design. The unusual shape of the driver case and the blue accents definitely make these look unique.

These headphones may look thin and flimsy, but are actually much more durable than their look suggests. The headband is made out of metal and can take some flex without snapping. The plastics used also exude a quality feel.

When used on the go, these headphones get extra protection from the included carrying pouch. This pouch looks simple and is made out of pleather, which should protect these headphones from scratches.

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.