Install and test each tweeter. Like woofers, tweeters (which produce the high frequencies) can be easy or difficult to install, depending on the components originally installed in your car. If your car came with tweeters, you will simply install the new ones in the existing housing and connect them to the existing wiring harness. But if there’s nowhere to install them, you’ll have to create your own (or enlarge existing ones, use a mounting bracket, etc., if the original locations don’t fit). Fortunately, tweeters are much smaller than woofers, so the adjustments required will be minimal in comparison.
As with woofers, if your car isn’t already equipped with tweeters, you’ll need to connect them directly to the battery and stereo, as well as to the body ground.
Replace all speaker panels and grilles. Once all of the components of your new speaker system are installed, tested, and securely attached to the car, you can reattach any grilles or panels that you may have needed to remove to install the speakers. Be sure to save any removed screws before disassembly so that you can reattach the railings and panels correctly.
If you find yourself in the above situation, you can do two things: 1) replace your radio with an original one, which will give more power to the replacement speakers. 2) Amplify your car’s stereo equipment if you want to maintain the original look of your radio or if you possibly want to maintain a feature such as the steering wheel controls.
If you still have the factory radio installed, installing new speakers will not improve the sound quality. You may notice that your radio doesn’t have the deep bass common in the original speakers. This is because these speakers are often made with paper cones, which require less power to produce bass.