Monoprice MHP 839 ( 108323 ) vs 66 Audio BTS Pro

The mids are the star of the MHP 839’s sound signature. They are forward and have good clarity, making vocals and guitars sound really prominent, and gives the overall sound a distinctly warm feel.
The bass is very good. While not very forward, it is full, has good punch and comes off as quite natural.
The top highs are rolled off, which may muddle some of the music’s details. However, this also results in a smooth sound, as there is little to no harshness.

You can wear these the conventional way, or you can also choose to use these DJ style, where only one ear cup is held to the ear.

One cable is thinner and shorter which is great for mobile use. The other is longer and thicker which should work better when using the headphones indoors.

The cable is connected to the left ear cup via a 3.5mm cable, which can easily be removed. Storing the headphones or replacing a broken cable should be very easy to do.

The MHP 839 is very versatile. The sound signature is enjoyable, and can work well with a variety of genres. It also offers good passive noise isolation for studio/DJ use. The collapsible design with removable cables make it easy to bring on the go. This combination of features is rarely seen in the price range.

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.