Using an amplifier/speaker set-up in your car can boost the volume level and the quality of audio of your stereo system significantly. The amplifier supplies the power needed for high-output 6x9 speakers to reach their full potential, filling your can with sound or blasting it out the windows at passersby. Wiring speakers to an amp is not difficult, and you can save time and money wiring your own speakers to an amplifier rather than taking your car to the local audio shop to have the speakers wired up.
Measure and determine the length of wire you will need to reach from your 6x9 speakers to your amplifier. Most often 6x9 speakers are installed at the rear of the vehicle, and the amplifier sits in the boot, so you shouldn't need more than a few feet of wiring. Cut two lengths of dual cable speaker wire long enough for your project using wire cutters.
Strip the four ends of both of your speaker wires using a pair of wire strippers. This can be done carefully with scissors also, if you don't have a pair of wire strippers handy. Have about 1 inch of exposed wire on each of the eight ends, then fold the ends of each cable in half once. When you are done, you should have a mass of bare cable 1/2 inch long at the end of each wire.
Loosen the positive and negative speaker wire connectors of one of the speakers using a Phillips screwdriver. Insert the end of the positive (unmarked) cable of one of your speaker wires into the positive (red) connector and close the connector tightly with your screwdriver. Insert the negative (usually marked with a black stripe) cable of the same speaker wire into the negative (black) connector and close the connector tightly with your screwdriver. Repeat this process for the other speaker.
Open the positive and negative output connectors on your amplifier for the right channel with a screwdriver. Insert the end of the positive cable of the right speaker wire into the positive connector for the right output channel on your amplifier. Close the connector with your screwdriver to hold the wire in place. Insert the negative cable of the right speaker wire into the negative connector of the right output channel on your amplifier. Close the connector with your screwdriver. Repeat the process to attach the left speaker wires to the left channel output connectors.
Power on the amp and stereo and play a track through the CD-player or head unit and have a listen to your new high-powered speaker set-up. Adjust the output volume knobs on the amplifier for each channel to balance the sound according to your tastes.