To connect speakers to a desktop computer, the computer should be equipped with a sound card. In addition to the speakers, you need a power socket to plug the speakers into. Also, ensure the computer is turned off.
Plug the speakers into the power socket, and then locate the jack that is connected to the cable at the back of the speakers. There are small, round, color-coded sockets at the back of the CPU. Locate the socket that either is green or has the symbol of headphones marked on it. The socket may also be labelled as "Audio Out." Carefully plug the jack into this socket for a connection.
If there is resistance, don't continue pushing the jack in because you can damage the sound card. If the speakers feature a sub-woofer, check if your sound card supports multiple speakers. If it does, plug the jacks into the appropriately colored sockets. Turn on the computer and speakers to confirm whether the connection was successful. The computer may need to install some drivers for the speakers to work.
If you are connecting the speakers to a receiver or amplifier, simply connect the positive wire to the positive terminal and the negative wire to the negative terminal. The positive terminal is usually red and the negative terminal black. The same colors apply for typical positive and negative wires.