[ShaunIOW]

I have a Plantronics M90 Bluetooth Headset, but for some reason when I phone anyone the other person complains they can't hear me properly as there is an echo, even though at my end the call is perfectly fine and clear, as soon as I change the phone to built-in speaker then the person can hear me fine. This is happening with the 4 different phones I've tried it with - Sony Z3 Compact, Blackberry Leap, Blu Windows 8.1 phone and an Acer phone.

Any ideas? faulty headset? Would a new headset make a difference?

Cheers