Speaker cable terminates at the end in leads, two separate wires to be connected to positive and negative terminals on the back of a speaker and its corresponding connection to a receiver or amplifier. Although some speaker cables are sold with color-coded insulation to distinguish positive and negative, the wires themselves are identical.How to Determine Negative Vs. Positive Lead in Speaker Wires (Eric Ferguson/Demand Media)
Use speaker wire with two different colored strands. Common color combinations include yellow and black, and silver and copper.
Determine which of the two leads will be used for positive connections, then consistently connect this wire to all positive terminals on speakers and receiver equipment. For example, if you buy speaker wire with black and yellow strands, you might designate yellow as the wire lead for the positive connections.
Speaker wire that comes with identical insulation over the two strands should be stripped about 1/2 inch from the ends so you can identify the wire color. Often, speaker wire that appears to be a uniform color on the insulation actually contains two wire strands of different colors, typically silver and copper. In this case, choose a wire color for the positive and negative connections.
Label one of the leads with a piece of cellophane tape to designate it as either positive or negative if the insulation and wires underneath are identical in color.
Connect the lead labeled positive to the positive (red) terminal on the back of your receiver and the back of your speaker. Be sure you keep the line flat by running your fingers along the length of the speaker wire so it does not twist as you reach the other end for connecting it to the equipment. This could cause accidental wire crossing.
Stay consistent with all connections to prevent crossed wires that reduce speaker performance, ruin the stereo sound and may cause a short or blown equipment.