How to Install a Car Subwoofer

A car subwoofer is generally not a standard part of the car stereo system. You can purchase a separate subwoofer on your own and install it in the stereo as it exists. You can also purchase a subwoofer as part of a stereo kit that you build and design. In either case, subwoofer installation is not too difficult to do at home. You'll need the following tools and materials:

• Subwoofer
• Subwoofer box and installation kit
• Amp that's appropriate for the subwoofer
• Screwdrivers
• Glue
• Wires for the stereo system
• Enclosures and brackets
• Drill

Set up the Amplifier
If speakers are already set up through the amplifier, you need to slightly reconfigure them so that there's room for the subwoofer to be included as well. For instance, if you have a four channel amplifier and the speakers are already set up in the front and the back of the amplifier, reconfigure them so that the speakers that currently exist in the vehicle are set up in the front, leaving room in the back for the subwoofer.

Reroute the Power in the Amplifier
If you choose to install two subwoofers, reroute the power in the existing speakers through the subwoofer into mono. This allows the amplifier to channel twice the power into the subwoofer that it would have been able to otherwise. If you're only installing one subwoofer, don't bother with this step.

Wire the Subwoofer
Use 12-gauge wire to connect the subwoofer to the amplifier according to the instructions on the subwoofer or the amp. Be sure the subwoofer and the amplifier are compatible before you do this.

Set up the Box and Enclosures
Using the L-brackets that came with the box and enclosures, drill them into the area in the vehicle where you'll put the subwoofer. Now screw the subwoofer enclosure and box inside of these brackets. Make sure that you measure them out properly so the subwoofer will fit.

Secure the Subwoofer
Once the brackets and the enclosures are in place, move the already wired subwoofer into the area. Place the wiring behind the subwoofer so that it's hidden. Secure it in the enclosure with brackets.

Comparing Car Subwoofers by Size

Different types of car subwoofers are designed for a variety of uses and styles. Generally speaking, the larger the subwoofer, the more powerful it is. Subwoofer sizes are not always a good indicator of the quality of the sound, however, and many people don't want to simply have the loudest sound system possible in their car. You can often save money and end up with a better sounding audio system if you purchase smaller subwoofers as opposed to larger ones.

• 8" subwoofers. The smallest subwoofers generally available are those that are eight inches wide. These subwoofers are the most compact of any. They tend to have the least powerful sound. Many people end up purchasing two 8" subwoofers instead of one to help augment the bass sound of their car audio system. However, though the overall sound isn't very powerful, 8" subwoofers do have qualities that help to recommend them over their peers. First off, they are small and light, making them easily portable and helping them to fit into a lot of different types of cars. Additionally, they tend to be the least expensive of all types of subwoofers.
• 10" subwoofers. The next size up is usually 10 inches. These are slightly more powerful than the 8" size. They usually have an excellent mixture of clarity of sound and overall power. If you're not looking to produce the most massive sound you possibly can, and if your vehicle is a standard size, you'll likely find that a single 10" subwoofer will be more than adequate for your car stereo needs.
• 12" subwoofers. For a slightly broader and more powerful bass sound, a 12" subwoofer is the way to go. 12" subwoofers are often criticized for being a bit imprecise sounding and unclear. However, they provide a great mixture of loud sound and overall power without being too large to fit into most standard sized trunks. If you're looking to place your subwoofer underneath a seat in your car, a 12" subwoofer is likely as large as you'll be able to go, if not a bit too large.
• 15" subwoofers. The largest standard sized subwoofer is the 15". These subwoofers provide immense, booming bass sounds that will easily overwhelm other parts of the car stereo system if you're not careful. The quality of the sound generally is fairly muddy, but these speakers are great at getting your sound to project for a great distance.