I have been stumped by this for the last couple of months by now. That being to sync a UE BOOM 2 bluetooth speaker to my Alienware Laptop running Ubuntu. Firstly I have gone through alot of the obvious actions that one might take to get bluetooth working - installing blueman, using bluetoothctl, attempting to pair, trust, connect to the device. Deleting the device then refinding it and adding it. Essentially it is failing to connect. Through blueman it says failed to connect and through bluetoothctl it says: org.bluez.Error.AuthenticationCanceled org.bluez.Error.AuthenticationFailed
Secondly I have had the same device working on Ubuntu Studio (a while ago) and more recently Manjaro. I had reinstalled Manjaro and was unsuccessful in getting it to work again, so I came back to Ubuntu as I thought I might have a chance to get better support here.
The UE BOOM 2 speaker still works with an iPhone and I was able to succesfully connect to some bluetooth headphones today without any issue (to my Ubuntu setup).
So blueman is able to see the device, Bluetoothctl is able to recognize the device it connects with it momentarily then states that 'authenticationFailed' perhaps that is a clue(?).
Next fact I am with is I am not an expert in Linux and with moderate experience when it comes to changing scripts and so on, if something like that is required say in editing /etc/bluetooth/main.conf or the like. With a bit of insite perhaps it could at least be solved or figured out.
So I have had the device working in the past, it still works with an Iphone, Bluetooth is setup and working on my system but not connecting to this particular device. UEBoom2 themselves said the device is not compatible with Linux, though I have had it working before.
So in narrowing it down. Could it be that the UEBOOM2 device's ability to connect is diminished due to lack of not having an update (?) which would not work through my iphone and I cannot do through Linux currently. Could it be something to do with the Kernel in use ?( I have heard talk of this ) though I am not sure.
Also to add that in the past I could see the option within Pulse Audio and it would give the choice of using a digital profile or analogue so I am aware of that. Currently the UEBOOM2 speaker does not show up as an option and no option of A2DP is present (for that device) within PulseAudio.
Lastly I am asking for imput and not just rambling here for my own amusement. So please if someone can add to this with some constructive imput beyond have you installed blueman would be much appreciated.