A modification to your Honda Civic that greatly improves the stereo is the installation of a new set of rear speakers. Changing these out with better models can increase bass, improve high-end performance and just generally sound better. Although this isn't a difficult modification to do, multiples steps are involved in the process; many things must be done before you get the stock ones out. In this case, the project vehicle is a 2006 Honda Civic EX Coupe, but the process is similar for other vehicles as well.
Pop the trunk and locate the harnesses that connect the rear speakers to the stereo system. Unplug them using your hands. Unplug the harness for the third brake light using the same method.
Move into the interior of the vehicle and fold down the rear seats. Unscrew the two Phillips-head screws in the corner of the rear deck lid. Pull the rear deck straight out toward you to reveal access to the rear speakers.
Unbolt the factory speakers from the rear deck using the 1/4-inch ratchet and socket; lift them out of the deck and away from the vehicle. Mount the replacement speakers into the vehicle-specific speaker adapters using the hardware provided with the speaker adapters; bolt them into the rear deck using the factory hardware and a 1/4-inch ratchet and socket.
Slide the rear deck back into place. Screw the factory Phillips-head screws back into the deck to secure it in place.
Crimp the blue spade connectors onto the vehicle-specific speaker harnesses using the wire crimpers. Pop the trunk and plug the harnesses into the factory speaker harnesses. Run the red wire from the vehicle-specific speaker harness to the speaker. Plug the red wire into the positive terminal, and the black wire into the negative wire.
Turn on the stereo and make sure the rear speakers are working correctly. Adjust the fader to only the rear, then from left to right to make sure that it all works.
