Sennheiser HD380 Pro vs 66 Audio BTS Pro

The tight clamp on the 380HD helps create a seal that prevents quite a bit of sound leakage.

These headphones, as far as reference or pro-quality headphones go, are fun sounding. There is a slight boost to the lower frequencies which adds fullness and depth to the bass. The mids are also full-sounding, but there is a peak at the upper mid frequencies which can make guitars in heavy music sound harsh. The highs have good detail to them, but the peak in the top frequencies can also make the sound a bit grainy.

The 380s sit well over your ears and do not typically touch them when positioned correctly. This helps make them comfortable as the clamping force is distributed over a wide area, not directly on your ears.

The HD380 Pro is quite portable thanks to the detachable cable. Also, the included cable has a specially designed locking mechanism which prevents it from being detached accidentally.

The HD380 Pro can produce great sound even paired with low power amps. Some headphones require expensive amps to sound properly, but for these, even entry-level portable amps are sufficient.

These headphones can easily be brought along while traveling and spending time outdoors thanks to the included carrying case. The solid, clam shell design gives the headphones extra protection from impact and scratches.

The large ear cups and the strong clamp allow for impressive passive noise cancellation.

These headphones have fairly wide soundstage, despite being closed back.

The ear cups of the HD380 Pro can be folded up into the headband. This reduces these headphones' size and footprint, making these much easier to fit inside a bag.

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.