What Are The Best Free Air Subwoofers? (2022 Reviews)

Best Free Air Subwoofers

Is space a premium in your vehicle, but you don’t want to sacrifice on sound? Perhaps a free-air subwoofer is the right car audio component for you. So what are the best free air subwoofer options?

What is A Free Air Subwoofer?

In a free air setup, the subwoofer is attached to a fiberboard placed between the backseat and the trunk. This high-density board creates an airtight seal, effectively turning the entire trunk into an infinite baffle.

Of course, to create the infinite baffle, you’ll need to be sure that the trunk is completely sealed so that the sound waves from the back speakers don’t cancel out the front speaker. To have this setup, you may need to install or construct a new rear deck panel or vent to accommodate the subwoofers.

What is the Difference Between a Free Air Subwoofer and Traditional Subwoofer?

These subwoofers should have a more robust suspension and better cone dampening than traditional speakers. The toughened makeup is because the free air setup is less efficient overall when it comes to the lowest frequencies. These subwoofers get their dampening from the car’s suspension rather than the air pressure in a box designed primarily to house the car audio system.

Free air subwoofers will also require more amplifier power. Because of this, pay attention to whether the subwoofer is a single or dual voice coil. Dual voice coil subwoofers will give you more wiring options to connect an amplifier to your car stereo system.

While it may seem like an easier set up to use these subwoofers, your car may need a little more outfitting than with a standard subwoofer. The trunk provides the casing, so extra care must happen to seal the trunk. They have to ensure that sound waves from the rear of the speaker can’t reach the front of the speaker.

To do this, you may need a new rear deck panel and possibly new vents to help ensure the design is secure. If your car doesn’t already have this kind of sealing, it can cause you to add extra cost. These pieces could potentially be as much as a custom box.

What Do I Look for in a Free Air Subwoofer?

There are a few considerations for making your decisions. Let’s take a look at a few factors.

Power Handling

Your free air subwoofer will need a lot of power handling to provide the best sound. Many free air subs come packed with natural power handling, but you’ll want to look at the ratings, so you don’t end up with an underpowered sub that can’t push those low frequencies.


The free air subwoofer has to be able to withstand quite a bit sitting in the back of the car. Polypropylene cones, for example, are a flexible material designed to withstand some bumps and power. These polypropylene cones can also provide excellent sound.


Not all music utilizes the subwoofer the same way. Subs with a wide range of frequencies allow you to pick and choose the music and get excellent performance from your free air subwoofer no matter what. The sub should be able to hit this wide range of frequencies without distortion or power loss.

Why Should I Choose a Free Air Subwoofer?

Free air subwoofers may not be nearly as efficient as traditional subwoofers because of this suspension. However, there are a few good reasons to choose this type of speaker.

First, when you build out a sound system that uses a traditional box, it can take up a lot of space in your trunk. For those of you who don’t want to give up your storage space completely, free air speakers could be a good compromise.

Another reason would be for customization purposes. If you already can seal your trunk and you don’t need to buy a customized box, it could be a good option for using the materials that you already have.

You add far less weight to the trunk of your car with free air subwoofers, and there’s nothing to lift during installation. You retain access to little nooks and crannies in your trunk but still get a nice sound on the low end.

What Installation Choices Do I Have?

You do have a few choices for your free air installations. These will depend mainly on your preferences and the vehicle you have (although hatchbacks may not do well with a few of these options.

Rear Installation (Most Traditional)

Using the rear deck requires a bit of space, so if you have a larger sedan, this could be a good choice. The speakers are mounted on the top side of the rear deck and use the trunk space as the casing. You’ll need to make sure that the trunk is sealed, so a medium or high-density fiberboard behind the back seat and under the rear deck.

Backseat Installation

This option is usually less expensive than cutting into the rear deck, but you will lose some of your space. However, installation is straightforward and allows you to get your speakers up and running more quickly. It also doesn’t require as much modification. You will need to keep your seal, however.

Small Deck Installation

Many newer vehicles don’t have the space to mount a traditional deck. Instead, small decks provide better installation by venting the free air subwoofer through the trunk itself with a good seal. The speakers mount vertically, and the interior is sealed completely off from the trunk space.

What’s the Difference Between Free Air and Infinite Baffle?

They’re very similar choices, in that they don’t use a traditional box. However, with infinite baffle, you take care to seal off completely the back of the speaker from the front, so you have as little sound interference as possible.

With free air, you’re going to get some wave interference because the speakers aren’t sealed. However, for all but the most selecting audiophiles, this setup is a nice compromise from the difficulty of infinite baffle or the heaviness of a traditional box.

What Should You Consider When Purchasing a Free Air Car Subwoofer?

Since free air subwoofers are designed to be used in a larger area, there are some things to consider before purchasing, including:

  • RMS
  • Dual voice coils
  • Durability
  • Frequency range

RMS is a measurement that tells what the average power output of the free air subwoofer is over a measurable time. It’s listed as watts RMS in the product details and is different from peak power. Peak power measures power output in microseconds. The higher the RMS number, the longer your system can play without overheating.

Although a single voice coil does not perform better than a dual voice coil, the advantage of a dual voice coil is that it offers more wiring options, which allows you to hook it up to an amplifier. Since the RMS of free air subwoofers is considerably lower than competition grade models, the addition of an amplifier will add to your car audio enjoyment.

Because free air subwoofers are well, in the open air, rather than mounted in a box, you should consider the individual component’s durability.

Pay attention to the material composition of voice coils and spiders.

Voice coils can be made of copper or aluminum. Copper is more durable of the two metals. Spiders are often made from cotton, poly-cotton blends, or conex but can also have a Butyl rubber or Kevlar coating, which adds to their durability.

Audio frequency is measured in hertz (Hz). The higher the hertz number, the higher the sound frequency. Subwoofers are designed to amplify the bass and can produce a sound spectrum between 20 to 200 Hz. The lower the Hz frequency range is, the more bass is heard from the speaker.

What are the Best Free Air Subwoofers?

Armed with this information on what to look for, let’s consider what are the best free air subwoofer choices.

Quick Picks: Compare The Best Free Air Subwoofer Choices 2022

Best Overall
Skar Audio VD-8 D2 8" 600W Max Power Dual 2 Ohm Shallow Mount Car Subwoofer
Best Cheap Option
Pioneer TS-A300D4 12” Dual 4 Ohms Voice Coil Subwoofer - 1500 Watts (1 Subwoofer),...
Best Value for the Money
PIONEER TS-SW2502S4 10-Inch, 1.200 Watts Shallow-Mount Subwoofer
Skar Audio VD-8 D2 8" 600W Max Power Dual 2 Ohm Shallow Mount Car Subwoofer
Pioneer TS-A300D4 12” Dual 4 Ohms Voice Coil Subwoofer - 1500 Watts (1 Subwoofer),...
PIONEER TS-SW2502S4 10-Inch, 1.200 Watts Shallow-Mount Subwoofer
Best Overall
Skar Audio VD-8 D2 8" 600W Max Power Dual 2 Ohm Shallow Mount Car Subwoofer
Skar Audio VD-8 D2 8" 600W Max Power Dual 2 Ohm Shallow Mount Car Subwoofer
Best Cheap Option
Pioneer TS-A300D4 12” Dual 4 Ohms Voice Coil Subwoofer - 1500 Watts (1 Subwoofer),...
Pioneer TS-A300D4 12” Dual 4 Ohms Voice Coil Subwoofer - 1500 Watts (1 Subwoofer),...
Best Value for the Money
PIONEER TS-SW2502S4 10-Inch, 1.200 Watts Shallow-Mount Subwoofer
PIONEER TS-SW2502S4 10-Inch, 1.200 Watts Shallow-Mount Subwoofer

1. Skar Audio VD-8 D2 Shallow-Mount Car Subwoofer

The Skar Audio VD-8 D2 is an 8-inch dual 2 OHM shallow mount subwoofer.


  • 600 watts peak power handling
  • 400 watts RMS
  • Pressed paper cone
  • Frequency range 32 – 375 Hz
  • Sensitivity 83.2 dB
  • Xmax: 10.25 mm


  • Depth 3.94 inches

Skar Audio VD-8 D2 Shallow-Mount Car Subwoofer is a dominant bass producer. It has a 2-inch high-temperature copper voice coil, competition-grade cone surrounded by high-strength foam, Xmax of 10.25 mm, and a 2-layer Conex spider. It has 600W peak power with a whopping 400 watts RMS.

Its frequency response is 32 – 375 Hz, and the sensitivity is 83.2 dB. It does need 3.94 inches for mounting, so it may not be as small as you’d like for the area you have in mind. Skar provides a two-year limited warranty for this subwoofer.

2. Pioneer TS-SW2002D2 Shallow-Mount Subwoofer

The Pioneer TS-SW2002D2 is an 8-inch shallow subwoofer with dual 2 Ohm voice coils.


  • 600 watts peak power
  • Mica injected resin cone
  • Frequency response 20 – 200 Hz


  • 150 watts RMS

The Pioneer TS-SW2002D2 Shallow-Mount Subwoofer delivers excellent sound quality coupled with deep bass. The 8-inch subwoofer has 150 watts of RMS with 600 watts peak power. The mica injection-molded resin cone ensures accurate and louder bass reproduction.

The TS-SW2002D2 has a depth of just 2 5/8 inches. The Pioneer Shallow-Mount subwoofer is designed primarily to provide quality sound performance in spaces that traditional subwoofers won’t fit.

3. Pioneer TS-SW2502S4 Shallow-Mount Subwoofer

The Pioneer TS-SW2502S4 is a 10-inch single 4 Ohm shallow mount subwoofer.


  • 1200 watts peak power


  • 100 – 300 watts RMS
  • Depth 3 1 / 8 inches
  • Frequency response 20 -125 Hz

The Pioneer TS-SW2502S4 Shallow-Mount Subwoofer has a mica-injected resin cone and a single 4 Ohm voice coil. It has a frequency response of 20 – 125 Hz and 1200 watts peak power. However, it only has between 100 and 300 watts RMS and a frequency response of 20 – 125 Hz.

It has a depth of 3 1 /8 inches and, therefore, may not fit the area you wish to install it. Its sealed box volume is 0.35 – 0.7 cubic feet, while the ported box volume is 0.5-0.7 cubic feet. Consumers also noted that even though it is a 10-inch speaker, it will not fit into pre-cut mounts of that size, and some alterations made need to be done.

4. Rockford Fosgate R2 Ultra Shallow Subwoofer

The Rockford Fosgate R2 is a dual voice coil shallow mount subwoofer.


  • Mica injected polypropylene cone
  • Integrated spider venting
  • Anodized aluminum voice coil former


  • Mounting Depth 3.4 Inches

The Rockford Fosgate R2 Ultra Shallow Subwoofer has a peak of 400 watts and 200W RMS. The basket has integrated spider venting for better sound production. The mica injected polypropylene cone is durable, and the voice coil is made from anodized aluminum. It also has 12 AWG compression terminals and a linear spider with stitched 16 AWG tinsel leads.

The Rockford Fosgate R2 has a mounting depth of 3.4 inches, so even though the name says it’s ultra-shallow, it’s not as shallow as other subwoofers on our list.

5. Rockford Fosgate P3S D2-8 Shallow-Mount Car Subwoofer

The Rockford Fosgate P3S D2-8 is an 8-inch dual voice coil 2 Ohm shallow mount subwoofer.


  • 300 Watts peak power
  • Aluminum cones
  • Spider venting design
  • Mounting depth 2.66 inches


  • 150 Watts RMS

The Rockford Fosgate P3S has been specially designed for both sealed and vented enclosures. It has a mounting depth of just 2.66 inches. The cones are anodized aluminum. It is a dual voice coil 2 Ohm model with 150 watts RMS. The push terminals are 10 AWG nickel-plated. Rockford Fosgate provides a one-year limited warranty for its subwoofer.

6. Infinity REF1000S Shallow-Mount Subwoofer

The Infinity REF1000S is a 10-inch shallow mount subwoofer.


  • 800 watts peak
  • Sensitivity 89dB
  • Frequency response 35 – 175Hz
  • Selectable Ohm


  • Top mount depth 3.27 inches
  • 200 watts RMS

The Infinity REF1000S is a low-profile SSI subwoofer. It has a sensitivity of 89 dB and a frequency response of 35 – 175Hz. The Infinity has 2 or 4 Ohms, which is selectable and a 2-inch voice coil.

According to the manufacturer, the Infinity REF1000S Shallow-Mount Subwoofer is designed to work best in moderately sized sealed, vented, and prefabricated band-pass enclosures, so this may not be the best subwoofer for your setup. Although free air and infinite baffle mounting are possible, the power handling is reduced in these situations because there is no air volume to stiffen the suspension.

Final Thoughts on the Best Free Air Subwoofers

Now that we’ve discussed what are the best free air subwoofers, if you are hoping for competitive grade booms, you may be disappointed in your free air subwoofer even if you set it up as an infinite baffle. The free air subwoofer is designed differently, and the difference means that the bass isn’t there for all brands.

Bearing that in mind, for a free air subwoofer, we recommend the Skar Audio VD-8 D2 Shallow-Mount Car Subwoofer. It has a high-temperature copper voice coil, more durable than aluminum. It also has a competition-grade cone packed in high-strength foam, giving you the best sound for this type of subwoofer. The 2-layer conex spider is also tough enough to last.

It has a good frequency response range, and 400 watts RMS along with a sensitivity of 83.2 dB. Overall, it’s not too shabby. The only drawback is the more considerable mounting depth when compared to the other models on the list.

Brett Gordon

The engine behind editing at DigMyRide and the brains behind its build. During the day, Brett is a thirty-something dude from SoCal climbing the corporate ladder, but by night, he spends his time contributing to the online world of automotive tech & trends.