Installing a subwoofer with a built-in amp can enhance the bass response and overall sound quality of your car’s stereo system.
So, if you’re ready to take your car’s audio system to the next level, let’s find out how to install a subwoofer with a built-in amp.
To install a subwoofer with a built-in amp, connect the power wire from the battery to the amplifier’s power input, the ground wire from the amplifier to a metal surface in the car’s chassis, and the speaker wire from the amplifier to the subwoofer. Also, connect the remote and RCA wires from the amplifier to the stereo.
In this article, we’ll walk you in details through installing a subwoofer with a built-in amp in your car.
Required Tools for the Installation
Getting ready to install a subwoofer with a built-in amp? Let’s ensure you have all the necessary tools on hand before you start.
This can help prevent any unwanted trips to the hardware store in the middle of your project.

Basic Tools
The following tools are generally needed when installing any type of car audio equipment:
- Wire Cutters: You’ll need this to cut wires to the correct length. Always remember, it’s better to have a wire that’s slightly too long than one that’s too short.
- Wire Strippers: These are used to remove the plastic insulation from your wires before connecting them.
- Screwdrivers: A set of both flat-head and Phillips-head screwdrivers will be handy for removing and securing various components.
- Drill: This might be needed to create new holes for mounting the subwoofer, depending on where you choose to install it.
- Soldering Iron and Solder: Although many connections can be made using wire connectors, soldering wires together provides a more secure and durable connection.
Specialized Tools
In addition to the basic tools, you may need the following specialized tools for installing a subwoofer with a built-in amp:
- Power Probe: This is used to test power and ground connections to ensure everything is correctly hooked up.
- Panel Removal Tools: These are essential for safely removing panels from your car’s interior without damaging them.
- RCA Cables: You’ll need these to connect the subwoofer to the head unit.
- Wiring Kit: This will include a power cable, ground wire, turn-on wire, and potentially a wiring harness if your factory stereo requires it.
Remember that the exact tools needed may vary slightly depending on your specific car model and the subwoofer you choose.
Where to Install the Subwoofer
Choosing the right location for your subwoofer with a built-in amp can greatly influence the audio output in your car.
Common locations include the trunk, under a seat, or in custom-built boxes that fit into various nooks within your vehicle. It really depends on the size of the subwoofer, your car’s space, and your personal preferences.
From a sound perspective, placing the subwoofer in the trunk generally results in more resonant and deeper bass as the sound waves have more space to bounce around.
But if you prefer a more subtle bass that doesn’t overpower the other audio frequencies, an under-the-seat location may work better, especially if you decide to use a small thin sub.
Running Power to the Subwoofer
After deciding on the location, you’ll need to run power to the subwoofer.
This involves connecting a power cable from the car’s battery to the subwoofer. You’ll have to route the cable through the car’s firewall and under the carpet or through conduit, depending on your car’s layout.
It’s important to avoid running the power cable parallel to audio cables to prevent electrical interference, which could affect sound quality.
When it comes to a separate fuse, it’s highly recommended to install an inline fuse on the power cable near the battery. This acts as a safety feature that will cut off power in case of a short circuit, protecting both your subwoofer and your car.
Connecting the Subwoofer to the Car’s Audio System
Once the subwoofer has power, it’s time to connect it to your car’s factory stereo or head unit.
This involves using RCA cables to connect the subwoofer’s inputs to the stereo’s outputs.
If your head unit doesn’t have RCA outputs, you can use a line output converter (LOC) to convert speaker-level outputs into RCA outputs.
Adjusting the Subwoofers Settings
After everything is hooked up, you’ll want to adjust your subwoofer’s settings for optimal sound quality.
You need to set the gain, low-pass filter, and bass boost. The goal here is to achieve a balanced sound that complements the rest of your audio system rather than overpowering it.
Take your time with this step and tweak the settings while listening to a variety of music to achieve the best results.
Common Installation Mistakes for a Subwoofer With a Built-in Amp
Finally, it’s worth discussing some common installation mistakes to help you avoid them:
- Incorrect Wiring: This is by far the most common mistake. Always double-check your wiring connections to ensure they are correct.
- Overlooking the Ground Wire: The ground wire is just as important as the power wire. It should be connected to a clean, bare metal part of the car’s chassis for the best performance.
- Improper Gain Setting: Setting the gain too high can lead to distortion and potentially damage the subwoofer. Always set the gain according to the manufacturer’s instructions.
- Skipping the Fuse: As discussed earlier, a fuse is essential for safety. Never skip this part of the installation process.
Installing a subwoofer with a built-in amp is an exciting project that can greatly enhance your car’s audio system. With careful planning, the right tools, and a bit of patience, you can achieve an excellent result.
Troubleshooting Common Issues with the Subwoofer With a Built-in Amp
Every now and then, despite our best efforts and meticulous attention to detail, we might encounter a few hiccups after the installation of the subwoofer with a built-in amp.
Fortunately, most issues are common and have simple solutions. Let’s discuss a few of them:
Subwoofer Doesn’t Power On
If your subwoofer isn’t powering on, the first thing to check is the power connection. Make sure that the power cable is securely connected to both the battery and the subwoofer.
Also, don’t forget to check the inline fuse I mentioned earlier. If the fuse has blown, your subwoofer won’t power on. You’ll need to replace the fuse and find out what caused it to blow to prevent a repeat.
Subwoofer Doesn’t Produce Sound
If the subwoofer powers on but doesn’t produce any sound, there may be an issue with the audio connections.
Check the RCA cables connecting your subwoofer to your head unit to ensure they’re securely plugged in at both ends.
If your car’s factory stereo didn’t have RCA outputs and you used a line output converter, verify those connections as well.
Subwoofer Produces Distorted Sound
Distorted sound can be a result of a few things. It could be a sign that the gain on your subwoofer is set too high.
Try lowering the gain and see if the distortion goes away. If not, the distortion could be due to a poor ground connection.
Check the ground wire to ensure it’s securely connected to a clean, bare metal part of your car’s chassis.
Subwoofer Produces a Humming or Buzzing Noise
If your subwoofer is producing a humming or buzzing noise, it’s likely due to a ground loop.
This usually happens when the head unit and the subwoofer have different ground reference points, which creates a small AC current that produces a humming sound. The solution is to ground your devices to the same point in the car’s chassis.
Choosing the Right Subwoofer With a Built-in Amp
When it comes to sound systems, every car owner has unique needs and preferences. Therefore, it’s crucial to understand your specific needs before you dive into the process of choosing a subwoofer with a built-in amp for your vehicle.
There are a few factors to consider when selecting the right subwoofer for your car.
#1. Firstly, consider the size of the subwoofer. This largely depends on the available space in your car and how much you’re willing to give up for your new sound equipment.
For example, a compact sedan may only be able to accommodate an 8 or 10-inch subwoofer, whereas a larger SUV or pickup truck might have room for a 12-inch or even 15-inch model.
#2. Secondly, take a look at the power output of the built-in amplifier. This can be expressed in two ways: RMS (root mean square) and peak power, although I recommend looking only at the comparable RMS values.
RMS is a measure of continuous power handling and is the more reliable indicator of how loud your subwoofer will play consistently. Peak power, on the other hand, is the maximum power that the subwoofer can handle in short bursts.
You’ll want to choose a subwoofer whose RMS rating matches or is slightly higher than the power your head unit or factory stereo can deliver.
#3. The third factor is the subwoofer’s sensitivity, which measures how much sound a subwoofer can output given a certain amount of power.
Subwoofers with a higher sensitivity rating will play louder at the same power level compared to those with a lower rating. If your car’s factory stereo has a low power output, a subwoofer with high sensitivity could be a good match.
#4. Now, let’s talk about compatibility. Your new subwoofer should be compatible with your car’s factory stereo. This requires a bit of research about your specific car model and the subwoofer you’re considering.
Some subwoofers come with a wiring harness that plugs directly into your car’s factory stereo, making the installation process a breeze.
#5. Finally, consider the benefits of a subwoofer with a built-in amp, also known as a powered subwoofer. The main benefit is that it simplifies the installation process as it eliminates the need for separate amplifier wiring.
It also saves space as both the subwoofer and amplifier are contained within a single unit. And don’t worry, even though it’s a two-in-one package, for most users it doesn’t compromise on power or sound quality.
Conclusion
Adding a subwoofer with a built-in amp to your car is more than a technical upgrade, it’s a way to elevate your audio experience.
A subwoofer enhances the sound quality and adds depth to your music, making every journey in your car a musical adventure.
Installing a subwoofer is a rewarding experience that deepens your understanding of your vehicle and connects you to your love for music. With the right tools, subwoofer, and approach, you can transform your audio experience and enhance the moments you have in your car.
FAQ
What Is a Subwoofer With a Built-in Amp?
A subwoofer with a built-in amp is a speaker system that combines a subwoofer and an amplifier in a single unit. The built-in amplifier powers the subwoofer, delivering enhanced bass and sound quality.
How Do I Choose the Right Subwoofer With a Built-in Amp for My Car?
To choose the right subwoofer with a built-in amp for your car, consider factors such as size, power, and frequency response.
The subwoofer should be compatible with your car’s stereo system and match your personal preferences for sound quality and bass.
What Tools Do I Need to Install a Subwoofer With a Built-in Amp?
To install a subwoofer with a built-in amp, you will need tools such as a screwdriver, wire cutters, crimping tool, and a drill.
You may also need a mounting kit, wiring harness, and other accessories depending on your vehicle and the subwoofer you choose.
How Can I Connect a Subwoofer With a Built-in Amp to a Factory Stereo?
To connect a subwoofer with a built-in amp to a factory stereo, connect the preamp signal to the subwoofer using RCA cables.
Where Should I Install the Subwoofer in My Car?
The subwoofer in a car can be installed in various locations, such as the trunk, rear deck, or under a seat. The ideal location depends on factors such as the subwoofer’s size, the car’s acoustics, and personal preferences for sound quality and bass.
How Do I Run Power to the Subwoofer With a Built-in Amp?
To run power to a subwoofer with a built-in amp, you will need to connect the power wire from the battery to the amplifier’s power input. You also need to connect the ground wire from the amplifier to a metal surface in the car’s chassis.
Do I Need to Install a Separate Fuse for the Subwoofer With a Built-in Amp?
It’s recommended to install a separate fuse for the subwoofer with a built-in amp. The fuse protects the amplifier and the car’s electrical system from damage in the event of a power surge or short circuit.
How Do I Adjust the Settings on My Subwoofer for the Best Sound Quality?
To adjust the settings on a subwoofer for the best sound quality, you can adjust the gain, crossover, and phase settings.
The gain controls the volume of the subwoofer, the crossover adjusts the frequency range of the subwoofer, and the phase aligns the subwoofer with the other speakers in the car.
How Can I Troubleshoot Common Issues With a Subwoofer With a Built-in Amp After Installation?
To troubleshoot common issues with a subwoofer with a built-in amp after installation, you can check for loose connections, damaged wiring, and blown fuses.
You can also test the subwoofer with a multimeter or a sound meter to identify any issues with the signal or the sound quality.
Can I Install a Subwoofer in a Car Without an Amp?
Although technically possible, it is not recommended to add a subwoofer to the car without an amplifier. A subwoofer without an amp would rely on the power from the car’s stereo system, which may not provide enough power for optimal performance.
How Does the Location of the Subwoofer Affect the Audio Output?
The location of the subwoofer in a car can affect the audio output, as it interacts with the acoustics of the car’s interior.
Placing the subwoofer in a corner or against a wall can enhance the bass response, while placing it in the center of the car can provide a more balanced sound.
How Do I Wire a Subwoofer in a Car?
To wire a subwoofer in a car, connect the power wire from the battery to the amplifier’s power input, the ground wire from the amplifier to a metal surface in the car’s chassis, and the speaker wire from the amplifier to the subwoofer.
You also need to use an RCA and the remote wire to connect the subwoofer to a factory stereo.
How Does Adding a Subwoofer With a Built-in Amp Improve My Car’s Audio System?
Adding a subwoofer with a built-in amp to a car’s audio system improves the bass response and overall sound quality. The subwoofer’s built-in amplifier provides more power and control over the bass frequencies, resulting in a fuller and more immersive sound experience.