Positive speaker wires have a positive (+) symbol or a negative (-) symbol to indicate the corresponding connector on the wires. Some terminals are also color coded; a common color code that is used is black for negative and red for positive.
It is important to match up the positive wire to the positive speaker terminal and the negative wire to the negative terminal in order to make the speaker function at its best. Some speakers will have four connectors in the back, with two positive and two negative. These also need to connect properly to the corresponding terminal to function properly. The positive or negative label should be marked clearly on the wires; if it the markings are not clearly indicated, it is important to thoroughly check the wires to find the proper marking. After the system is installed, conduct a sound check to test the system. If the wires are set up incorrectly, the system sounds suboptimal. The user can try the connections both ways and decide which way sounds better. Setting it up the wrong will not do any immediate damage to the system as long as it is not left that way for an extended period of time.