Speaker wire usually connects to a speaker via a set of terminals on the back of the enclosure that accept bare wire. But some speakers, such as those used in PA systems, use a 1/4-inch jack to make it easier and quicker to connect and disconnect them from an amplifier. The speaker wire used to connect the two will need to have a 1/4-inch plug on the end.
Pull apart the two leads at the end of your speaker wire for a distance of several inches. Identify one lead as the positive lead; this lead is usually marked with a "+" sign on the jacket or colour-coded with a red stripe.
Remove 1/2-inch of insulation from the end of each of the leads with a set of wire strippers.
Unscrew the jacket from the 1/4-inch plug. Slide it over the ends of the speaker wire, with the threaded end of the plug facing the end of the wire. Push it back several inches from the end of the wire.
Place the positive lead of the speaker wire against the centre tab on the back of the plug and solder it in place. Place the other lead against the outer tab and solder it to the tab. Let the solder joints cool.
Slide the plug's jacket down the wire and screw it onto the plug.
Soldering irons are very hot at the tip -- use caution when handling.