Sennheiser HD 598 SR vs 66 Audio BTS Pro

The large ear pads feature a velour surface and a soft foam material underneath. The comfort of the headband is also notable. It features a synthetic leather material with a thick foam inside. In combination, these cushioned parts feel like pillows on the head.

These headphones are in a price range that is quite affordable, yet offers sound and build quality that is beyond the standards in its price bracket.

The bass takes a bit of a back seat compared to the other frequencies, yet is still enough to give fullness and punch to the sound. The mids are the star of these headphones' sound signature. They are clear and a little bit forward, which give a lot of extra detail and presence to guitars and vocals. The highs are pretty crisp and clean, and complement the other frequencies really well.

Even for open back headphones, the soundstage that the HD 598 produces is amazing. It is quite wide yet natural at the same time, which makes it feel like you're listening to the artist perform in front of you live. This wide sound stage and great imaging also make these ideal for games and movies, as these can enhance audio immersion.

This makes the headphones quite easy to store, and the cable easy to replace. Also, the attachment mechanism is a twist to lock system which minimizes the chances of the cable getting disconnected while in use.

The BTS Pro is quite robust and can withstand some minor splashes of sweat or rain as these are sweat-proof. They are not completely water-proof though, so you should not get them soaking wet.

There is good detail in the highs and the mids can also be heard clearly with very little muddiness. The lower frequencies are boosted, resulting in a good level of depth and power to each bass thump.

The BTS Pro ear cups sit on the ears with hooks keeping them in place. The flexible connecting band provides good clamping force and can adjust to your head size with continued use. Combined with cushioning on the cups, these are comfortable to wear and will stay in place.

Bluetooth connectivity allows the BTS Pro to connect with smartphones and compatible music players wirelessly, so cables won't be an issue.

66 Audio's Motion Control iOS App gives users added functionality, including EQ control and presets selection, battery status indicator, and even headphone position tracking. These features can improve the listening experience and also minimize the chances of you losing these headphones.

With up to 40 hours of playback time at full charge, it's more than enough for most listening sessions. You won't have to charge these frequently.

A hard shell carrying case is included, which can protect the headphones from minor impact and also make transport much easier. The case also has good aesthetics.

They are easy to bring on the go as the ear cups can be folded into the headband. This further reduces the already slim and compact size, making them easy to chuck into a bag when on the go.

The right ear cup of the BTS Pro features buttons for controlling headphone features. You can play/pause tracks, increase/decrease volume as well as answer/end calls by pressing the corresponding buttons, negating the need to pull out your phone to do so.

You do not need to take the BTS Pro off in order to answer incoming calls. There is a built-in microphone which allows you to easily take or make calls in the middle of your run or workout.