How to Convert a Home Subwoofer into a Car Audio Subwoofer

You can convert a home subwoofer into a car audio subwoofer by removing the wiring from the home subwoofer and attaching a car amplifier to it. This effectively changes the home sub from AC to DC power, which is needed for operation in a car. 

My name is Donovan, and I’m a home studio enthusiast and general audio nerd. I spend most of my days writing and recording music, and I’ve learned a lot about home audio over the years. I know through first-hand experience how to convert a home subwoofer into a car sub. 

This post will show you how to convert a home subwoofer into a car audio subwoofer. I’ll provide you with some necessary details to make this happen safely and effectively and highlight some other related information. 

Let’s get started. 

Key Takeaways

  • It is possible to convert a home sub into a car sub, but you need to open up the home sub to access the wiring and make some modifications. 
  • Home subwoofers are designed differently than car subwoofers, so you won’t necessarily get the same audio quality when converting one into the other. 
  • You must use a car amplifier with a home subwoofer to get it to work in the car. Home subs are designed to take higher voltage, and you won’t be able to power it properly without an amp. 
  • Making this modification isn’t that complicated if you have a little knowledge of basic electronics and are handy with tools. 

Initial Thoughts

It’s typically best to use electronics for their intended purposes rather than make modifications allowing for different uses. A car subwoofer is better left in the car, and a home subwoofer makes more sense in your home theater. 

In the next section, I’ll explain more about the differences between these types of subwoofers, but just know that converting a home sub to a car sub requires some technical know-how. 

It’s not extremely complicated, but if you’re not somewhat handy and good with tools, I don’t recommend diving into this task. You can easily mess up your car audio system if you don’t set things up correctly. 

That said, if you have a spare home subwoofer lying around your house and want to try installing it in your car, it is possible. You just need to make a few modifications and use a separate car amplifier. 

Car Subwoofer vs Home Subwoofer

Car subwoofers and home subwoofers are not the same thing. Even though they serve the same purpose of boosting the low-end frequencies of your stereo or home theater system, their design, and construction differ from one another.

Car subwoofers are designed to be used in smaller spaces, whereas home subwoofers are designed for larger spaces. This means you can get some funny audio abnormalities when you modify a home sub to be used in the car and vice versa. 

There are also pretty significant differences in how much power each type of sub is designed to take. Home subwoofers usually have a built-in amplifier and are designed to handle more volts – as in the 120v that comes from a wall socket in the house. 

A car subwoofer requires a separate amplifier that is designed to work with your car battery, which only puts out 12v. This is why you need to change the wiring and use an external amplifier to get the modification to work. 

Another difference is that home subwoofers run on AC power, and car subwoofers run on DC power. This is the standard difference between home appliances and car appliances, and it also affects wiring and the need for a separate amplifier for car use. 

How to Convert a Home Subwoofer into a Car Audio Subwoofer

Alright, now let’s take a closer look at this project. You can’t just plug a home subwoofer directly into your car audio system without making a few important modifications. But it is fairly easy to do if you have the know-how and some basic tools. 

You’ll need to have a car amplifier for this to work, so purchase one of them ahead of time. You don’t need a super high-powered car amp because you don’t want to push the home sub to full capacity. 

Here’s what you’ll need to make this modification happen:

  • Home subwoofer
  • Car amplifier 
  • Screwdriver
  • Extra speaker wire
  • Electrical tape
  • Wire cutters/strippers
  • Small wood screws (optional)
  • Small hand or power saw (optional)

I list the wood screws and saw as optional because you can use these to make your modified home sub look better and attach the amp to the top of it with your screws. But you don’t need to do any of this to make the project work. It can just save some space in your car. 

Step 1: Take Out Wiring Assembly in Home Subwoofer 

The first step for this project is to take out the existing wire assembly in the home subwoofer. This is the most significant step towards modifying the sub to work in your car. 

Depending on how your subwoofer is built, you’ll either need to unscrew a panel to access the wires or use something to cut through it. If you see screws, use the screwdriver to remove the screws and then set the panel aside. 

If you need to cut through the subwoofer, do so very carefully so you don’t cut or rip any of its internal components. I suggest using a small hand saw to give you more control, but a jigsaw could also work. 

Once you remove the inside of the subwoofer, you can get rid of everything except for the wires connecting the speakers. You’ll want to remove the power cable and cut the wires that connect to the speakers. 

Be sure to leave as much length as you can on the wires connected to the speakers. This will help you attach it to an amp later on. You might need to tape or splice additional wire if you don’t have enough length. 

Step 2: Visual Inspection to Direct Wiring

Now that you have the subwoofer opened up and the wiring removed, you need to take a quick visual inspection of the speakers inside. This will help you figure out how you will go about wiring the subwoofer to your amp. 

If you only see one set of wiring terminals in your subwoofer, you have a single voice coil. If you see two sets of terminals, you have a double voice coil. Either will work for the modification, but just find out which one you have before continuing to the next step. 

Step 3: Prep Your Car for Install

Now it’s time to clean out your car and prep it for installing the new sub and amp. The backseat is a common location for these items, but you can set things up underneath a seat or wherever you have room. 

I recommend installing the sub and amp in the trunk or rear compartment. This area of the car has more room and will give you better audio overall. There probably isn’t enough room under a seat for a home-sized subwoofer.

Remove any clutter or larger items that might get in the way of the installation. You also might want to vacuum the car before you put the sub and amp in place. 

Step 4: Screw Down the Sub/Amp (Optional)

This step is optional, but I recommend doing it so your subwoofer and amp don’t slide around or fall over while driving. 

You can attach the amp directly to the subwoofer using woodscrews or attach the amp to your car somehow. Most amps have small holes around the perimeter of the unit specifically for this purpose.

If you attach the amp directly to the sub, you’ll have a neat and tidy little setup with one unit instead of two separate pieces. This is a convenient way to go about the setup if your amp fits easily on your sub.  

Most home subwoofers won’t have attachment brackets because they aren’t designed for use in the car. You can attach some L-style brackets to the sub and then to the floor of your vehicle as an option to increase stability. 

Step 5: Wire the Subwoofer to the Amp

Now you need to connect the subwoofer to the amp by using the speaker wires you exposed within the sub. You’ll need to locate the positive and negative terminals on the speaker and attach the other end to the corresponding terminal on the amp. 

If your sub has two voice coils, you’ll have four exposed wires to deal with. You can twist or tape the center wires together within the subwoofer and use the other two to connect with the amp. This creates a bridge that functions the same way as a single voice coil wiring. 

Depending on your amp, you may need to unscrew the terminal point to fit the wire in properly. Be sure to tighten the screw again once the wires are in place. Other amp styles might just have a clip you press to open, which goes down automatically. 

Step 6: Connect Sub/Amp to Car Stereo

The last step is connecting your modified subwoofer and amp to the rest of your car stereo. The exact method for this can vary depending on your stereo setup.  

If your system already has an amp, it should have a subwoofer channel. You’ll need to run a power wire from that amp into the smaller amp. A larger gauge wire, 12 or 14, works well for this. 

Again, you might need to unscrew the attachment points for this wire, just like you did with the speaker wires. Ensure the wires on both ends are firmly in place once installed. 

If you aren’t using an amplifier in your existing setup, you’ll need to attach the subwoofer cable from your car stereo head to the sub/amp setup. You should be able to locate this up near the wiring harness of your stereo. 

Attach this wire the same way by unscrewing the attachment points of lifting up the tab to hold it in place. 

If your car stereo does not have a subwoofer cable, you’ll need to install one. You might need to remove your stereo head and wiring harness to access this. 

Step 7: Start Bumping

That’s all there is to it. You should now be able to use the modified subwoofer in your car. You can make adjustments to the volume or eq of your sub from the stereo head to get the ideal sound you want. 

If you run into any issues, inspect all of your connections to ensure that the cables are held in place properly. Also, make sure that your stereo is working properly before installing the sub to know that it’s fully functional. 


Here are a few short answers to some of the most commonly asked questions related to converting a home subwoofer into a car audio subwoofer. 

Can you wire a home sub to a car? 

It is possible to wire a home sub to a car with a few modifications. You need to convert the sub to DC power by removing the existing AC power cord and then attaching the speaker wires to an external car amplifier. 

Can you replace a home subwoofer with a car subwoofer? 

It is technically doable to replace a home subwoofer with a car subwoofer, but it’s not recommended because of the differences in impedance and amps between them. A car subwoofer is not designed to handle as much power as a home subwoofer. 

What is the difference between car subs and home subs? 

Car subwoofers run on DC power and are designed to work better in smaller spaces. Home subwoofers run on AC power and are designed to work in larger spaces. They can be interchanged with some modifications. 

Does a car subwoofer need an amplifier? 

A car subwoofer does need an amplifier to operate correctly. If you already have a stereo amplifier in your car, you can connect the subwoofer to this, and it will work. But you’ll need to install an amp to power the sub if you don’t. 

Can you hook up any subwoofer to your car? 

You can, in theory, hook up any subwoofer to your car. But using a car subwoofer designed for that purpose is better and easier. If you use a home subwoofer, you’ll need to make some modifications and use an amp to get it to work. 

Final Thoughts

If you have an extra home subwoofer lying around the house, you can use it in your car by modifying the electronics and connecting it to an amplifier and then to the rest of your stereo system. You’ll need a few tools and supplies, but it’s relatively easy to do. 

Even though modifying a home subwoofer into a car subwoofer isn’t that complicated, I think using a proper car sub is better if you can. You’ll get better audio quality, and it won’t take up as much room in your ride!

Have you ever used a home subwoofer in your car or vice versa? Why? Let me know in the comments below.

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