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How to Install Subwoofers

Susan J

Louder is Better

Recently I wrote a quick DIY to installing a new radio head unit in a car. In this blog post I’ll discuss a related topic: how to install subwoofers in your car. You can save a bunch of money if you can do this yourself instead of paying a professional car audio shop to install them.

A few weeks ago my friends and I installed a sound system in another friend’s 4Runner, and it’s a piece of cake with the right tools. It’s best to do this at the same time as you change your radio, because you will have to take the radio back out when you install subs anyways.

A Sub..What?

In case you’re wondering what a subwoofer actually is… a subwoofer is a loud speaker that processes very low audible frequencies, AKA it produces a loud, bass sound. Not only do subwoofers enhance the bass sound, they improve the overall quality of your sound system.

Put simply, imagine having concert quality sound in your car!


Things You'll Need (The Goods)

  1. The subwoofers
  2. A subwoofer box
  3. Amplifier
  4. Amplifier kit

Be sure the subwoofer box is designed for the speakers and the amp isn’t too strong or weak for the speakers. This blog post is an aid for those who already have the speakers installed in the box.

Steps to Installing Your Subwoofers

  1. Position yourself under the dash and find an opening in the firewall to run the power wire through. In my kit, this power wire was a thick orange wire. In most kits, the gauge size ranges from 8 to 0. The kit also had a fuse a few inches away from the connector that goes to the battery. Get it close to the battery, but don’t connect it.
  2. Next, pull out the dash and the radio head unit. You’re going to want tape your remote wire to your RCA cable and thread it up from under the passenger side dash to the opening where the radio was. From there, connect the remote wire to the wiring harness or straight wire it to the corresponding wire from the radio and connect the RCA cables.
  3. Now it’s time to run the wires back to where the amp will be placed. I ran the power wire down the left side and the RCA and remote wire down the right side. As a safety precaution, you should run the wires down the passenger side. Simply run all the wires to the trunk or wherever you are placing the amp. Finding the right spot to mount the amp is important so that it’ll not move around or slide while you’re driving. Now, it’s just a matter of connecting the power cable, RCA, and remote wires to the amp.
  4. Afterwards, lift up the carpet near the amp and find a spot of exposed metal from the body of your vehicle to lay the ground wire. In my case, I had to sand off some paint in order to get a strong ground. A bad ground wire can create a lot of problems with the amp, so be sure you have good ground.
  5. Lastly, take your subwoofer box and place it in the car. At this point, you will connect it to the amp with the speaker wire. Walk back to the front of the car to your battery cable and secure the fuse to something in the engine compartment. I just twist tied it to a hose. Now, hook up your battery cable to the positive terminal on your battery.

Go ahead and test out your subwoofers and see that everything is connected correctly. If so, you can reassemble your dash and forget about your old music ways and welcome the new one with subwoofers!


This article was written based on our personal experience with installation of a subwoofer. It is in no way meant to be used as a definitive guide for installation. You should use caution when working with anything that involves live wires or electricity. If in doubt, always contact a professional. Any actions taken which are based on information from this post are taken at your own risk.

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