How to Install a Car Subwoofer at Home

One of the most important parts of any in-car audio system is the subwoofer. The subwoofer radically improves the audio output of otherwise flat-sounding car speakers, and their installation does not involve any rocket science, either!

We start off with gathering the basic requirements and materials, and follow it up with a step by step approach to set up your subwoofer in little time.

Which Subwoofer do I Need?

This decision is one you’ll have to make based on the intended quality of sound as well as the space in the boot you’re willing to sacrifice. There are various brands to choose from, and each brand has varieties of subwoofers based on price points and physical sizes.

The various sizes available are in the range of 10 inches to 18 inches. Choose wisely! Get the tape measure out before laying down the cash on a subwoofer. The best car subwoofer is the one which satisfies all your needs in terms of size, price and audio quality.

How do I Mount the Subwoofer?

The best method to position your subwoofer is at an incline to the wall of the boot surface, where the speaker is positioned outwardly. Make sure your box incorporates the rake angle properly. If you’re in doubt about the angle, ask the car audio shop for more information. Generally the angle shouldn’t be more than 30 to 45 degrees from the bottom of the boot.

Materials You Will Need

Get your notepad ready – it’ll take a short trip to the hardware store to get all your materials. You’ll require fiberboard for the base of the subwoofer – around ¾ inch width is perfect. Then, you’ll need screws, silicone, clamps and PVA glue to secure the subwoofer in place. You’ll need electrical wire for power connections as well as speaker wire.

You’ll also require some carpeting and a cup (commonly known as the terminal cup) which has terminals to connect speakers via speaker wires. The basic approach is to build an enclosure around the subwoofer so that it stays in place, and complete the wiring process alongside.

Tools you’ll require include a tape rule and a pencil for measurements, and a screwdriver as well as drilling equipment and a soldering iron.

Let’s start with building your subwoofer enclosure!

Building the Box for the Subwoofer

Take measurements of the front face of the box. Make sure you leave a few inches over and under the outside radius of the speaker part of the subwoofer.
The rest of the sides of the box must be cut exactly according to the measurements of the subwoofer.
To mark the positions of the mounting screws, and to create the opening for the subwoofer, take the speaker as an in-place template.
The saw is used to cut open the hole where the circular speaker will be positioned. Then, drill the holes for the mounting screws to a size which is smaller than the actual screw diameter.
Drill and make a hole in the side panel, or the rear panel for the speaker wire routing. Make sure to drill a hole which matches the size of the terminal cup.
Using silicone sealant, secure the terminal cup in its intended position. The terminal cup is the place where the speaker wire will go through, so until there is enough strength in the positioning of the cup, apply sealant properly. Too much sealant in the wrong position will only lead to a mess!
Use the PVA glue to secure the side and rear panels for the box into position. Follow this step by firmly positioning the screws in place.
Seal all joints by using silicone sealant to secure the box into its final position. At this stage, you should not put the speaker into position yet. Make sure the box is airtight and there is no excess space for the subwoofer to move around.

Congratulations! The basic layout for the subwoofer is now ready and in position. You can now put the box aside, and take a well-deserved break. The next steps aren’t nearly as technical, but just as important – so pay attention!

Carpeting the Box

With liberal amounts of PVA glue, put the carpet into position on all the surfaces of the subwoofer box except the front. Each of the side, rear and back surfaces must be properly covered with carpet lining.
You may cut a single hole for the front carpeting, but for a smoother finish, go in for segmented, sectioned carpeting. Apply PVA glue on the front side and finish up covering the front with segmented sections of carpeting. As previously, the carpeting must be tight enough.

You’re just one step away from a life-changing audio experience. This step is the trickiest, since it involves soldering and wiring. If you’re unsure of your electrical handiwork, you should ask for help!

Wiring the Subwoofer into Position

Through the main speaker hole in the front, put the wires from the speaker into the box. This step is followed by soldering the wires to the rear end of the speaker, as well as the terminal cup’s terminals. Negative must be joined to negative, and the positive to the positive.
Now’s the time to secure your subwoofer into place with screws. This step needs utmost care, make sure you don’t miss any of the screws. Tighten the screws properly.
Place your constructed cover over the speaker and secure it into position with screws.
Connect the relevant wires from your in-car entertainment system, or an in-car amplifier if you have one. If you need help in figuring out how to connect your subwoofer with the amplifier, do check out out our detailed guide.

Now’s the time to test the connection. If you’ve followed the steps to the T, your system must be working perfectly fine. Check the wiring or the connections in case the system doesn’t work – they’re the most likely offenders in this case.

This wraps up the process on installing a car subwoofer as a do-it-yourself project. Hope you had fun doing it!

About the Author Roger

Roger is a mechanical engineer by day and grease monkey by night, who spends all his free time tweaking things in his car. His love for car audio equipment is only matched by his desire to help others find the best products suited to their needs.