I installed a Denon surround sound receiver with Boston speakers and subwoofer the other day. The receiver and subwoofer are connected to a power surge strip into a typical electrical outlet in my wall. I shut off the power surge strip last night. When I turned on the power surge strip this morning, and then the turned on the receiver and tv, loud popping sounds came out of the speakers. What do you think oculd be the cause? Voltage build-up released when I turned on the power surge strip? Speaker wires touching? I have a wireless router and cable modemn about 6 feet from the receiver. Any ideas? Thanks in advance.