Buzzing sound coming out of back speakers

Make/model of receiver or amplifier?

Type of speakers -

The buzzing is a 60 hertz ground loop - most likely.

Make sure all connections are properly grounded and that all connections are firmly in place. Assure that wires are connected correctly. If necessary, trace each wire to assure proper connection.

Older phonographs have ground connections. Most receivers have a ground lug nut connection.