AKG K81 DJ vs 66 Audio BTS Pro

Despite the compact size. the bass is full, has great impact, deep extension yet is not loose. The low end also has a natural quality to it that makes these headphones great for music that is performed using real instruments.
The mids are slightly recessed, but also have a natural tone. The highs are the most recessed or rolled-off, but the detail and airiness of the music is not totally absent. This quality helps give the sound a smooth and pleasing tonality.

The K81 can be used “DJ style”, wherein only one ear cup is in contact with the head. The cups have a smooth swivel action so they can be rotated to face outwards. A user can choose to hold one ear cup up to his or her ear while flipping switches or turning knobs on the mix board with the other hand.

While these are already quite compact, the ear cups can be folded into the headband to reduce their size even further. This makes them easy to stuff inside a bag and travel with.

The clamping force is not too much at all, so acceptable levels of pressure will be applied on the ears. Also, the ear pads are thick with ample pleather padding on the surface. This combination provides adequate cushioning between the ear cups and sides of the head.

The aluminum headband itself has some good flex. Combined with the sliding mechanism of the ear cups, K81 can be adjusted to fit a wide range of head sizes. Also notable are the numbered steps on each side of the headband, which allow for accurate and consistent ear cup positioning.

Although it's mostly made of plastic, the materials don't feel cheap at all. Aside from feeling sturdy, the plastics have a smooth rubber coating which makes them feel premium to the touch. Also, the headband is made out of aluminum which is significantly more durable than an all plastic one.

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.