How to Add Bass Without Reducing Trunk Space? (Subwoofer Tips)




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Adding bass to a car’s audio system can be a challenge, especially when trying to preserve trunk space.

However, with the right equipment, it is possible to achieve a powerful sound without sacrificing storage space.

To add bass without reducing trunk space, consider installing shallow-mount subs, custom-designed subwoofers, or small powered subwoofers. These options can preserve trunk space while still delivering powerful bass. Additionally, the suitable amplifier can help increase volume and bass without sacrificing trunk space.

Tip: For those looking for a compact and efficient solution, a small powered subwoofer like the Sound Ordnance B-8PT (link to Amazon) can be a great option.

Alternatively, a JL Audio Stealthbox, custom-designed to fit your vehicle’s shape and decor, can provide powerful bass without taking up much space. This is a more expensive option, but it makes the car interior look much better with stronger and more precise bass.

In the article below, I will explore the different bass-adding options and discuss their pros and cons.

How Do I Create More Bass Without Sacrificing Lots of Space in the Car?

Many, if not most car audio enthusiasts often face the challenge of adding bass to their car’s audio system without sacrificing trunk space.

The bass response of car stereos can often be lacking, leaving the music incomplete and unfulfilling. This can be particularly frustrating for those who enjoy a full, rich sound in their music.

Trunk space is a precious commodity in many cars, and sacrificing it for a subwoofer can be a difficult decision to make. Whether you use your trunk for grocery shopping, carrying luggage, or simply as extra storage, losing that space can be a significant inconvenience.

Fortunately, there is a solution for adding bass to your car’s audio system without sacrificing trunk space.

Install a Shallow Mount Free Air Subwoofer

By replacing the rear deck speakers with shallow-mount subwoofers, you can add powerful bass without reducing the amount of room in your trunk. 

Shallow-mount free-air subwoofers use the trunk space as their enclosure, eliminating the need for a bulky subwoofer box. They are designed to work when installed on the rear deck, and the entire trunk volume acts like a large enclosure.

That makes them the perfect solution for car audio enthusiasts who want to improve their bass response without sacrificing trunk space.

Install a Powered Subwoofer

Another option is to install a small powered subwoofer, which combines the subwoofer and amplifier into one compact package.

This eliminates the need for separate components and makes installation a breeze. Simply put the subwoofer in a convenient trunk location, connect the wiring to your car battery and RCA wires to the stereo.

The compact size of these subwoofers means that they won’t take up much room in your trunk, allowing you to keep your space while improving your bass response.

Whether you choose shallow-mount subwoofers or a small powered subwoofer, adding bass to your car’s audio system without reducing trunk space is a smart choice for anyone who wants to enjoy a powerful, full-bodied sound in their music.

Install a Customized Subwoofer Enclosure

If you want to maximize the bass response of your car audio system but don’t want to sacrifice trunk space, a custom-designed subwoofer enclosure may be the right choice for you.

A custom-designed subwoofer enclosure is designed specifically for your vehicle. They can deliver powerful bass without taking up much room in your trunk and are most often installed on the side walls.

This makes them the perfect choice for car audio enthusiasts who want the best of both worlds – powerful bass and ample trunk space.

Benefits of Replacing Rear Deck Speakers With Subwoofers

Adding a subwoofer to your car’s audio system can greatly improve the audio quality by adding more bass and volume.

The bass response of your music will be more full and powerful, giving you a more immersive listening experience that typical speakers cannot achieve, even those expensive ones.

Comparison of Free-Air Subs With Traditional Subwoofers

Traditional subwoofers often require a large enclosure, which can take up a significant amount of space in your trunk.

This can be a major drawback for those who want to add bass to their car’s audio system without sacrificing trunk space.

Additionally, traditional subwoofers often require a separate amplifier to increase volume and bass. At the same time, some shallow-mount free-air subs are designed to work without needing an external amplifier.

This makes them a more streamlined solution for anyone looking to add bass to their car’s audio system without changing the overall volume level.

Installing Subwoofers for Maximum Effect

Installing subwoofers in your car is not a complicated process, but it is important to follow proper guidelines to ensure maximum performance and longevity.

The process typically involves:

  • Mounting the subwoofers in the rear deck.
  • Connecting the wiring to the car battery.
  • Choosing the suitable amplifier to power the subwoofers.

Importance of Proper Mounting

Proper mounting is crucial for getting the best performance from your subwoofers. The subwoofers should be securely mounted in the rear deck to ensure they are stable and not prone to movement.

This will help to produce the best possible bass response and prevent any damage to the subwoofers over time.

Selection of the Right Adapter Plates and Modifications

To install shallow-mount free-air subs in the rear deck, you may need adapter plates that fit perfectly in the factory openings since most subwoofers are larger than typical factory speakers, even those mounted on the rear deck.

Adapter plates may require modification to fit properly, such as cutting the plastic plates or modifying the factory speaker grilles.

Sometimes, you may need to choose distance rings made of MDF or plywood.

Choosing suitable adapter plates and making the necessary modifications is essential for a clean and professional-looking installation.

Choosing the Right Amplifier

Choosing the right amplifier is critical if you want the best performance from your subwoofers.

Skar Audio SK-M5001D Compact Monoblock Class D MOSFET Car Amplifier, 500W

While there are many compact amps suitable for speakers regarding the subwoofer, I recommend buying a proper monoblock or stereo amp if you have more than one sub. 

Excellent examples are monoblocks from Skar (link to Amazon). They are powerful enough to deliver the necessary power to the subwoofers while not being expensive and do not produce any heat.

Examples of Small Powered Subwoofers

If you prefer a powered subwoofer’s simplicity, several great options are available.

The Sound Ordnance B-8PT (link to Amazon) is a popular choice for those looking to add powerful bass to their car’s audio system without sacrificing trunk space.

Sound Ordnance B-8PTD 8" Powered Subwoofer

This small powered subwoofer packs a big punch and is easy to install, making it an excellent choice for those who want to improve their bass response without the hassle of separate components.

It is a one-stop solution that frees you from the hassle of dealing with a separate sub, amp, and enclosure. In addition, this sub is designed to perform better than its predecessor and can quickly round out your upgraded 6.5-inch door speaker system in your car or truck.

Want to take your audio experience to the next level? Check out my article on installing speakers on a truck bed for expert tips and tricks.


The B-8PTD comes in a rigid molded ABS plastic enclosure that serves as the sub’s sealed enclosure and can withstand extreme pressure changes without reverberating or buzzing.

The compact circuit board of the 125-watt RMS Class D amplifier is mounted inside the enclosure and powers the sub.

The 8″ aluminum cone of the sub holds its shape even when playing hard and keeps the lowest notes clean and clear.


The B-8PTD is a powered subwoofer with a built-in Class D amplifier with 125 watts RMS and 250 watts peak power which is quite significant for such a small driver.

It has a frequency response of 40-200 Hz and a variable low-pass crossover of 80-200 Hz. The variable phase control ranges from 0-180 degrees, and the bass boost control ranges from 0dB to +10dB.

The sub also has preamp- and speaker-level inputs and an auto-turn-on switch that works with most speaker wire input connections.


The B-8PTD has several convenient features to make tuning and adjusting your bass easier.

The neat, clean, and easy-to-understand controls are located on one side of the sub, opposite all the connections, so you won’t get tangled in wires while adjusting.

The control knobs and switches are not recessed, so you can make adjustments by hand without needing a tiny screwdriver. The sub also comes with a wired remote control for added convenience.

Ease of Use

The B-8PTD is easy to install and use. Whether you mount it under your car seat or in an out-of-the-way location in the cab of your truck, the sub will surprise you with its impressive bass and ability to mesh perfectly with the rest of your system.

The sub also has preamp- and speaker-level inputs, making it easy to connect to just about any system, even a factory stereo.

Comparison of Powered Subwoofers With Traditional Subwoofers

Powered subs offer several advantages over passive models.

  • Firstly, they combine the subwoofer and amplifier into one compact package, eliminating the need for separate components. This makes installation much easier and less time-consuming. 
  • Secondly, powered subwoofers are designed to work together, ensuring that the individual components deliver the perfect amount of bass for their size and power ratings.

When comparing both types, traditional subwoofers require separate components, including an amplifier, which can be more complex to install and require more space in your trunk.

Enhancing Sound Quality without Sacrificing Space

Shallow-mount free air subs are designed to be mounted in the rear deck of your car, allowing you to add powerful bass to your audio system without sacrificing trunk space.

They use the trunk space as their enclosure, eliminating the need for a separate box, which makes them perfect for car audio enthusiasts who want to improve their bass response without taking up too much space.

Overview of the Benefits of Custom-Designed Subwoofers

Custom-designed subwoofers, such as the JL Audio Stealthbox, offer a unique solution for car audio enthusiasts who want to enhance their audio quality without sacrificing space.

These subs are designed to fit in an unused area of your car and blend in with the vehicle’s interior, making them virtually invisible. The result is that you have plenty of room for luggage and groceries and a great sound system.

Comparison of Custom-Designed Subwoofers With Traditional Subwoofers

Custom-designed subwoofers also offer several advantages over traditional ones if your space is the first priority.

  • Firstly, they are designed to fit in an unused area of your car and blend in with the vehicle’s interior, making them virtually invisible.
  • Secondly, they are hand-crafted to ensure superior rigidity and more interior volume, allowing the sub to play louder, deeper bass.


Adding subwoofer to your car audio system can significantly enhance the audio quality of your music by adding deep, powerful bass to the mix. 

However, choosing the right subwoofer for your vehicle can be a complex process. Thankfully, several options allow you to add bass without reducing trunk space or sacrificing sound quality.

Whether you choose a powered subwoofer, shallow-mount free air subs, or custom designed subs like the JL Audio StealthBox, you can be sure of getting the bass you want without sacrificing your trunk space.


How Do I Add a Subwoofer to My Car Without Sacrificing Trunk Space?

There are several options to add a subwoofer to your car without sacrificing trunk space.

  • One option is to install a shallow-mount subwoofer, which is designed to fit in tight spaces.
  • Another option is to install a custom-fit subwoofer enclosure to your trunk, maximizing the available space.
  • You can also consider a powered subwoofer, which includes an amplifier and subwoofer in one compact unit that can be easily installed in your trunk.

What Is the Best Type of Subwoofer for Trunk Installation?

The best type of subwoofer for trunk installation will depend on your specific needs and the available space in your trunk.

A shallow-mount subwoofer or a powered subwoofer might be the best choice if you have limited space.

On the other hand, a custom-fit subwoofer enclosure might be the best option if you have more room in your trunk and want something more classy.

Is It Difficult to Install a Subwoofer in a Car Trunk?

The difficulty of installing a subwoofer in a car trunk will depend on your level of technical expertise and the specific subwoofer you choose.

Some powered subwoofers are very easy to install and come with detailed instructions, while others may require more technical know-how.