I've just got a Paradigm PDR8 sub from richer sounds and I loved it! I've had 3 subs now and this by far the best. The problem is I left my telephone (BT DECT phone) on top of the sub but when the phone rang the usual high pitched ring had a nice bit of bass behind it. After that the sub has started buzzing I've moved all electrical equipment away from the sub but it still buzzes. What haev I done and how can I reverse it???