JBL Synchros E40BT On-ear Bluetooth Headphones Review

JBL Synchros E40BT on-ear headphones

JBL announced their new range of headphones back in May, including the E50BT over-ear bluetooth headphones and the ones I was most interested in – the E40BT on-ear headphones which I received for review.

The headphones are available in red, white, blue or black and are a great balance between sound, comfort and portability. They are light and portable with a foam backed leatherette padding on the top section and ear-cups. The headphones were comfy with the ability to adjust the vertical position and the inward turn angle of the ear-cup. Unfortunately however they don’t adjust outwards, so if they’re tight on the back of your ears you can’t ‘loosen’ them.

The key specs:

  • 16 hours of battery life
  • Frequency response 10hz to 24KHz
  • 40mm drivers with PureBass performance
  • Bluetooth connectivity or cable connectivity (for non Bluetooth devices, or for when you run out of charge)
  • Ability to ‘push’ your music to another pair of E40BT headphones to listen in tandem with a friend

Music quality sounded great, with great representation of mid and high notes. If I had a criticism it would be that the bass could be better, but for £80 headphones playing over Bluetooth it was entirely acceptable.

Voice calls were very clear and the ear-cup-based microphone with “PureKonnexx echo-cancellation technology” worked well with callers able to hear me clearly, even in noisy environments such as walking along a road while outdoors.

Charging is done via a custom cable that is USB on one end and a 2.5mm audio jack on the other. A button on the front of the left ear-cup turns the headphones on or off with a short press. Press and hold the same button to go into Bluetooth pairing mode at which point the button will flash quickly between red and white – you can then initiate the connection from your Bluetooth phone or MP3 player.

JBL Synchros E40BT On-ear Bluetooth Headphones Review - folded with charging cable

On the left side are the audio controls, and although they have no tactile cues, they are simple enough to locate and press and after using them for a while become quick and easy to use.

Top and bottom are the volume up and down buttons, at the front (indicated by the circle) is the play/pause button, which also acts as the answer/end button when a call comes in.  You can also use this button to skip forward a track (2 presses) or back a track (3 presses).

JBL Synchros E40BT On-ear Bluetooth Headphones Review - button controls

The headphones have an interesting feature JBL calls ShareMe™ technology which lets you to stream music wirelessly to another ShareMe-equipped headphone so you can share your music, or any audio, with 2 headphones from one device. The back button triggers this sharing mode, with no musinc playing, press the button once, and on a second set of compatible headphones press the sharing button twice to ‘pair’. Playing music is now shared between the two headphones. Press the Sharing button again to disconnect.

I couldn’t test this, having only one review set, but it seems like a great idea, as long as your friends have compatible JBL headphones of course.


Lightweight and compact, these are great quality headphones at an extremely modest price.


The main disadvantage of the E40BT headphones is the charging cable, which is non-standard and means you always need to travel with it to charge the headphones.

While they can function as a standard cabled headphones if they run out of battery, the E40BT connector is 2.5mm so you need the supplied (or similar) 2.5mm to 3.5mm converter cable if you want to plug it into a normal phone or MP3 player.


These are extremely good, portable, headphones. The on-ear design offers good noise isolation while the compact, folding design allows for easy transport in a bag, taking up as little room as possible. Although the sound could perhaps be improved, you will struggle to find a set of headphones that sound this good and have these features for the money. They’ve had a permanent place in my bag and I find myself using them far more than I thought I would.

>> The JBL E40BT headphones are available from £79.99 on uk.jbl.com

>> The E40BT Quick Start Guide (pdf)

This post was written by Rob Gordon, an IT geek, gadget lover and blogger. Rob has been using the internets since 1994 when the only streaming video was that coffee pot in Cambridge (rip).... Follow Rob on Twitter - @robgordon - about.me/robgordonuk