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How to Install a Spare Wheel Subwoofer?

Are you looking to add some extra ‘bump’ to your car’s audio system but do not have room for a full-size subwoofer?

If you are limited with the space, installing a spare wheel subwoofer can be an easy and cost-effective way to improve your vehicle’s sound, but how can you make it right? Let’s find out.

To install a spare wheel subwoofer, follow the steps below:

#1. Open the trunk and remove the spare tire.

#2. Attach the subwoofer’s mounting plate to the spare tire well using the included hardware. 

#3. Connect the power and ground wires from the subwoofer to the car’s electrical system.

#4. Connect signal wires from the subwoofer to your car stereo’s subwoofer output.

#5. Turn on the system to test it.

#6. Reinstall the spare tire in the trunk and secure it. 

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Tip: When you plan to install a spare wheel subwoofer, there are two options to choose from:

Passive sub, for example, JBL BassHub (link to Amazon)

Active sub, the excellent is the JBL BassPro Hub (link to Amazon)

Both are excellent choices, and the decision should come down to whether you want to install an external amplifier in the trunk.

If not, you should choose the powered (active) subwoofer. Otherwise, go for a passive one.

In this article, we’ll walk you through the process of installing a spare wheel subwoofer in your car.

What Is a Spare Wheel Subwoofer and How Does It Work?

A spare wheel subwoofer is a type of subwoofer that is designed to be mounted inside the spare tire well of your car’s trunk.

It typically consists of a woofer, amplifier, and wiring harness and is powered by the car’s electrical system.

As you know, traditional subwoofer boxes can be quite large and cumbersome, taking up valuable trunk space.

CERWIN Vega 600 watts Active Spare Tire Application Subwoofers Series (VPAS12ST)

On the other hand, a spare wheel subwoofer fits neatly inside the spare tire well, leaving plenty of room for other items. They’re also relatively easy to install if you have the right tools and equipment.

Installing a Spare Wheel Subwoofer

Before you get started, you’ll need to gather all the necessary tools and equipment. Here’s a list of items you’ll need:

#1. Spare Wheel Subwoofer Kit

This should include the woofer, amplifier, wiring kit or harness, and mounting plate. Make sure to get a kit that’s compatible with your car.

#2. Screwdriver

A screwdriver is always handy to attach the mounting plate to the spare tire well and wires to the ports.

#3. Wire Stripper

Wire stripper helps remove the wire’s plastic covering to allow it connection with the terminals.

#4. Electrical Tape

Electrical tape can secure any exposed wires and protect them from shorting out.

#5. Wire Connectors

You’ll use wire connectors to splice the subwoofer’s wiring harness to the car’s electrical system.

Installation Guide

Now that you have all your tools and equipment, you’re ready to get started:

#1. Open the Trunk and Remove the Spare Tire.

The first step in installing a spare wheel subwoofer is to open the trunk and remove the spare tire.

Of course, spare wheel subwoofers cannot be mounted outside the car, so if your vehicle has a spare wheel below the trunk, you will not be able to use this subwoofer type.

#2. Attach the Subwoofer’s Mounting Plate to the Spare Tire Well Using the Included Hardware.

Once you have removed the spare tire, you’ll need to attach the subwoofer’s mounting plate to the spare tire well.

The mounting plate is a flat, circular piece of metal or plastic that will hold the subwoofer in place. It should have the hardware to attach to the spare tire well, such as screws or bolts.

To attach the mounting plate, simply place it in the spare tire well and use the included hardware to secure it.

Make sure the mounting plate is level and properly aligned before tightening the bolt, as this will ensure that the subwoofer sits centered in the wheel.

#3. Connect the Power and Ground Wires From the Subwoofer to the Car’s Electrical System.

Once the mounting plate is securely in place, you’ll need to connect the power and ground wires from the subwoofer to the car’s electrical system. The power cable will typically be red, while the ground wire will be black.

To connect the power wire, you need to run it to the positive terminal on your car’s battery. Once the wire is under the hood, you need to install a main fuse which should be as close to the battery terminal as possible.

To connect the ground wire, you’ll need to find a metal surface on your car’s frame that is free of paint and rust, and since the subwoofer will be in the trunk, the ground point should also be in the trunk.

For example, this could be a bolt or screw already in place from the backseat, or you may need to drill a hole and attach a grounding bolt.

Once you’ve found a suitable grounding spot, attach the end of the ground wire to it using a ring connector, but make sure to connect it to the bare chassis metal, not to the paint.

#4. Connect Signal Wires From the Subwoofer to Your Car Stereo’s Subwoofer Output.

After you’ve connected the power and ground wires, you’ll need to connect the signal wires from the subwoofer to your car stereo’s subwoofer output.

The signal wires are usually RCA, carrying the audio signal from the stereo to the subwoofer.

You’ll need to locate the subwoofer output on your car stereo to connect the signal wires.

On the back of your stereo, you should find a dedicated set of RCA jacks labeled “subwoofer” or “sub out.”

Once you’ve found the subwoofer output, connect the signal wires to the corresponding jacks.

One more wire you must remember about is the blue remote turn-on/off.

This small, thin wire will carry the signal from your car stereo to the subwoofer amplifier, telling it when to turn on and off.

#5. Turn on the System to Test It.

After you’ve connected all of the necessary wires, it’s time to turn on the system and test it out.

Turn on your car and stereo, then increase the volume to a moderate level. You should be able to hear the subwoofer producing low-frequency sound.

If you don’t hear anything, double-check your connections to ensure everything is secure.

If the subwoofer is working properly, you may need to adjust the amplifier’s gain and the bass boost. Also, adjust the stereo settings for the best sound quality if you have an equalizer.

Many car stereos have a built-in equalizer that allows you to adjust the balance of bass, mid-range, and treble frequencies.

I like playing with different settings to find the best spot for different music types, and I recommend doing the same.

#6. Reinstall the Spare Tire in the Trunk and Secure It With Any Necessary Hardware.

Once you’ve finished testing the subwoofer and adjusting the settings on your car stereo, it’s time to reinstall the spare tire in the trunk.

Place the tire back in its designated spot and use any necessary hardware, such as bolts or clips, to secure it.

When installing a spare wheel subwoofer, I also recommend checking the air pressure in the spare tire to ensure it’s properly inflated.

Most car manufacturers recommend a specific tire pressure for the spare tire, usually found in the owner’s manual or on a sticker inside the trunk. Use a tire pressure gauge to check the pressure and add air if necessary.

Is a Passive or Active Spare Wheel Subwoofer Better?

Both passive and active spare wheel subwoofers have their advantages and disadvantages.

Here’s a quick rundown of the main differences between the two types:

Passive Spare Wheel Subwoofers:

#1. A passive spare wheel subwoofer does not have a built-in amplifier. Instead, it relies on an external amplifier.

#2. One of the main advantages of a passive spare wheel subwoofer is that it allows you to choose your amplifier, which means you can customize the power and sound quality to your liking.

#3. On the other hand, installing a passive spare wheel subwoofer requires a bit more work, as you’ll need to install both the woofer and amplifier separately.

JBL 11" Passive Spare tire subwoofer System

Active Spare Wheel Subwoofers:

#1. An active spare wheel subwoofer has a built-in matching amplifier. This means that all the necessary components are included in a single package, making the installation easier.

#2. One of the main advantages of an active spare wheel subwoofer is that it’s a plug-and-play solution, so you don’t need to worry about installing an external amplifier.

#3. However, active spare wheel subwoofers are generally less customizable than passive subwoofers, as you’re stuck with the amplifier included in the package.

Ultimately, deciding between a passive or active spare wheel subwoofer will depend on your specific needs and preferences.

JBL Basspro Hub - 11" powered subwoofer system, Black

A passive spare wheel subwoofer might be the way to go if you want maximum flexibility and customization. On the other hand, if you want an easy, plug-and-play solution, an active spare wheel subwoofer might be a better choice.

Conclusion

Installing a spare wheel subwoofer is a simple process that can add a lot of bass to your car’s audio system.

Remember that every spare wheel subwoofer kit will be slightly different, so follow the specific instructions provided with your equipment.

Pay close attention to the wiring instructions, as improper wiring can cause damage to your car’s electrical system or the subwoofer itself.

If you’re not confident in installing the subwoofer, having a professional handle the installation is always a good idea.

FAQ

How Do I Know if My Spare Wheel Subwoofer Is Not Working Properly?

A few signs might indicate that your spare wheel subwoofer is not working correctly.

For example, the bass is not as strong or clear as it should be, or the subwoofer makes strange noises. If you see either of those, you can try a few things to troubleshoot the problem.

Most importantly, ensure that all the wiring is connected correctly and that the subwoofer receives power. You should also check the amplifier’s gain to ensure it is set at the right level.

What Can I Do if the Sound Is Distorted or Muffled?

If you’re experiencing distorted or muffled sound from your spare wheel subwoofer, try adjusting the volume and bass levels on the amplifier to see if that helps improve the sound quality.

If the problem persists, it might be a good idea to check if the sub is not damaged. If the woofer is damaged or worn out, it might need to be replaced.

How Do I Know if the Subwoofer Is Receiving Enough Power?

If you’re worried that your spare wheel subwoofer might not be receiving enough power, check all connection wires and make sure they sit tight in the connectors.

If the amplifier isn’t receiving power, the subwoofer won’t be able to function correctly. 

Powered subwoofers have matching amplifiers, so if the connection is correct, the subwoofer should receive enough current unless the car’s electrical system is damaged. For example, the battery flat or alternator does not work correctly.

In this case, you should check the power supply from the car’s electrical system and consult with a mechanic if necessary.

How Do I Properly Maintain My Spare Wheel Subwoofer?

Proper maintenance is key to keeping your spare wheel subwoofer in good working condition. One of the most important things you can do is to keep the subwoofer clean and dry.

If the subwoofer gets wet, it could be damaged, so you should avoid exposing the subwoofer to moisture or extreme temperatures, which can also cause damage to the speaker.