Speaker wire can operate poorly for a variety of reasons ranging from degradation of the wire casing along the length of the wire, which can cause wire wear and fraying, to fraying at the end of the wire which causes a poor connection, leading to bad sound. With a little skill with a soldering iron, you can use wire solder to repair a frayed wire or bad connection, and electrical tape to re-cover an exposed wire.
Strip any remaining plastic casing that encroaches on the area of the wire that you will be working with.
If you are repairing or reconnecting wires, and the wires are not still twisted together, begin with the wires at a 180 degree angle to each other (like this: ), then twist the frayed areas of the wire together until they look like a candy cane.
Secure the wire you wish to repair in a third hand mechanism, which will hold the wire still while you work the soldering iron.
Apply the solder to the exposed areas of twisted wire. You may need to touch the solder on the wire with the iron to finish melting it.
Allow the wire to cool to room temperature.
Carefully wrap electrical tape to cover the exposed areas you just soldered. If your wire is losing its protective covering, you can also use electrical tape to repair the damage.
Things You'll Need
Tin-Lead-Rosin wire solder
a third hand
If your speaker wires have frayed ends and a poor connection, some audiophiles recommend re-soldering your speaker wires to their connectors.
A soldering iron is extremely hot, and so is the wire solder after you heat it. Improper handling can cause serious and really painful burns.