Background and Identification
The Synchros E40BT is a pair of over-ear headphones with Bluetooth functionality. You can identify them by looking for the JBL logo on the sides along with the word “Synchros.” The exact model number “E40 BT” is written on the inside of the headband just above the earpads on each side. This model comes in black, blue, red, and white.
The headphones feature Bluetooth 3.0 so they can play audio wirelessly from a nearby device. They also have a regular 3.5 mm audio jack (a.k.a. an aux port) which you can use to play music even when the battery in the device has died. Speaking of which, you also use the 3.5 mm jack to charge the headphones via a USB to aux cord. Just plug the USB side of the cable into a power brick or a computer. You can buy replacement cords easily online.
The left side of the headphones are home to the music controls. Tap the upper section of the control disk to increase the volume and the lower portion to decrease the volume. The front button can play/pause music (one tap), go forward one track (two taps), or go back a track (three taps). You can also take calls using the microphone built into the left side of the device.
Since the earpads are one of the most common components to deteriorate on a pair of headphones, you can buy replacements for the E40 BT online. Here is a link to a replacement set on Amazon.
- Driver: 40mm
- Frequency range: 20 Hz to 22 kHz
- Impedance: 32 ohms
- Maximum SPL: 114 dB @ 30 mW
- 3.5 mm audio jack (for audio or charging)
- Buttons on left side:
- Volume up/down
- Multi-function button (play/pause, forward, back, etc.)
- Bluetooth 3.0