Sony MDR 7506 vs 66 Audio BTS Pro

The bass is just right. It may not have the deep sub-bass extension that bass heads crave for, but what is there is fast, tight and punchy. The mids are clear with a hint of warmth, which make vocals and guitars sound very clear and you can easily hear their sonic nuances .
The reproduction of highs is the part that these headphones really shine. They are crystal clear and highly detailed without adding hiss or harshness to the overall sound. Cymbal crashes and pings, for example, are very close to what you would hear if they were played right in front of you.

Despite being sub $100, the MDR 7506 can compete against headphones up to twice the price. These make for great headphones if you are just starting to get serious about your audio and you want a relatively inexpensive yet quality purchase.

The MDR 7506 is built outstandingly well, with high quality materials and with little to no creaks and unnecessary flex. These headphones have been around since 1991, which has given Sony a lot of time to refine the manufacturing process of these cans.

The yokes are collapsible and fold into the headband, reducing the headphones to a much more compact size. Included with each purchase is a synthetic leather pouch for added protection for the headphones when taking them on the go.

These leak very little sound compared to other over-ear headphones. The rear side of the ear cups is fully closed, which effectively minimizes sound leakage. With these, you can fully enjoy your music without disturbing people beside you.

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.