Best Free Air Subwoofer For Car 2023 – Buying Guide

Having plenty of options for subwoofers and the types, it gets hard to find the right product that fits your needs and requirements. The free air best subwoofer under 300 is another amazing thing to have in your car.

What are free air subwoofers?

Free air subwoofers offer multiple benefits in place of other alternatives, such as;

  • They do not require an enclosure.
  • Free air subs save a lot of space in the trunk or car. You do not have to keep a giant box that takes as much space as awkward it looks.
  • Besides space, free air speakers are cheaper than other alternatives.
  • Free air subwoofers do not have a built-in amplifier.
  • To compensate for an enclosure, free air subs need higher power and sensitivity.

The only drawback these speakers have is that they do not produce as much punch as you may expect in comparison to other subwoofers. This article offers a guide that would help you in choosing the best subwoofer under 300 for your car.

Let’s have a quick view on the best free air subwoofer under 300;

Buyer’s Guide |Best Free Air Subwoofer

The most important factors while making a purchase for your 8-inch free air subwoofers, which must not be overlooked are mentioned below. Whether you are looking for the best subwoofer under 300 or less and more, these factors directly impact the quality of the sound.

Let’s have a look at some features and specifications that must be your priority if you are looking for the best subwoofer under 300.



It is an important factor to consider for free air subwoofers as they do not have any enclosure, which makes it necessary to have adequate punchy bass no matter the set-up you have.

The average power known as RMS rating is the thing you need to consider in spite of what the peak power is. The maximum power of the speaker determines the overall quality and production of the sound.

Ideal RMS of sub:

250 to 500 watts is a good starting point for a subwoofer. There are subs with 1000 watts RMS or even more is not uncommon.

Frequency Range


There is no right and wrong, ideal and inadequate for frequency range while choosing a sub. It basically is a capability of a speaker to hear or produce sound within a range of frequencies like the human ear. A human ear is capable of hearing frequencies from 20 to 20,000 Hz. The lower the number, the lower the tone, and vice versa.

Choosing the frequency range for a subwoofer depends on your personal preference and the sound you want to hear.

Audio frequency subsets

Here is a little guide to understanding how much frequency is ideal for what kind of music or sound.

Frequency range is not the only component that makes a good subwoofer. Being one of the important factors amongst all, the right frequency surely adds to the overall performance of the subwoofers.



It accounts for how loud a subwoofer is capable of going within a given power. Free air subwoofers are different from enclosure subs, which requires them to have a good sensitivity rating.

How to measure the sensitivity of a sub?

If a subwoofer is rated at 90 dB, it means that with a power of 1 watt it will produce 90 dB of output, if measured from 1 meter away.

Ideal sensitivity for subwoofer

Anything greater than 90 dB is considered to be a good sensitivity rating for a free air subwoofer. Whereas, anything less than 90 dB is considered poor quality.

Voice coils

Coils attached to the apex of the speaker provide the motive force to the cone via a reaction of a magnetic field. It let the current pass through it. A single voice coil has one winding, whereas a dual voice coil has two separate windings.

Dual voice coils offer more flexibility and eliminate speaker to speaker series connection. For instance, an 8-ohm speaker and a dual 4-ohm speaker are similar.
Single coil speakers are easy to install, but dual coil speaker offers more versatility when it comes to connection.

The crux of purchasing the best free air subwoofer

All in all, if you are going to purchase the free air best subwoofer under 300 for your car, it must match your needs and requirements when it comes to music and usage.

You can either get stuck on one or you can do your research finding the most efficient, and durable subwoofer to save yourself from trouble. Besides the performance of the sub itself, the installation plays an important role in determining the sound quality.

Installation; Free Air Subwoofers


When it comes to installation, free air subwoofers do not require sound wave isolation like baffle systems.

Tips to install free air subs

The idea of the free air subwoofer is to eliminate the need for an enclosure. As these subs have no enclosure there are a few things you need to focus more on.

  • Things in the trunk have an effect on the sound.
  • Isolation for sound waves impacts the production of bass.
  • You may need sound-absorbing material for an installation.
  • Free air subs require modification in the rear end.
  • Insulation is necessary to better sounding system.
  • The sealing of a trunk adds weight to the sound.

You can save up time, money, and a lot of space installing free air subs in your car- but it must require some additional changes made in the rear of the car.

8 Best Free Air Subwoofer

We have gathered the best 8-inch free air subwoofers for your convenience that are capable of producing a good quality sound and are durable.

  1. JBL Stage810 – 8″ Subwoofer

JBL Stage best free air subwooferCheck Price On Amazon


Power Handling: 200Wrms, 800W peak

Impedance: 4 ohms

Sensitivity: (@2.83V): 88dB

Frequency response: 38Hz – 200Hz

Voice coil diameter: 1.5 in (38.8mm)

JBL Stage free air subwoofers are designed to deliver high-output and low-distortion bass with power handling capability. It offers 1000 watts peak power. JBL subs come in three sizes; 8″ (200mm), 10″ (250mm), 12″ (300mm), which can be used for every size of the vehicle.

Coming to design, these subs are provided high-efficiency with lightweight yet stiff polypropylene woofer cones with the hi-roll rubber surrounding. The unremarkable JBL signature sound by its individually tuned subs.


  • High-grade material for super reliability
  • Competitive tuned
  • Good value for the price


  • Lacks heavy bass sound

2. Infinity Kappa 8″ Car Subwoofer

Infinity Kappa free air subwoofer under 300
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Speaker Maximum Output Power: 1600 Watts
Peak: 1600 watts
RMS: 400 watts
Frequency Response: 34Hz – 200Hz

Infinity Kappa gives you a moving audio experience with its innovative, the best free air subwoofer that leaves you blown away. The Kappa Series subwoofers feature SSI™ (Selectable Smart Impedance). It is a HARMAN-exclusive impedance selector, that allows you to choose a 2- or 4-ohm impedance at the flip of a switch. Its aero-cooling design helps in keeping the voice coil cool while optimizing power handling offering long-term reliability. Distortion is highly minimized acoustically damped glass-fiber cones.

More performance! More flexibility! You get both when you step up to a Kappa subwoofer.


  • Selectable smart impedance.
  • Aero-cooled voice coil.
  • Acoustically damped glass-fiber cone.
  • Premium screw-down terminals.


  • None to be found.

3. Skar Audio IX-8 D2 8″ Car Subwoofer

Skar Audio best free air subwoofer


Peak Power: 300 Watts
RMS Power: 150 Watts
Advanced Air Flow Cooling System
Frequency Response: 30 – 350 Hz
Sensitivity: 83.2 dB

High performance and powerful subs, Skar Audio IX-8 D4 (IX series) is engineered to provide astonishing sound. It features a single stack ferrite magnet along with a competition-grade paper cone. High-roll foam surrounds the cone offering sound absorption. Speaking of the design, it utilizes an advanced airflow cooling design with a high-temperature 2-inch copper voice coil. This subwoofer performs at its rated power levels with ease.


  • Pressed Paper Cone
  • 2″ BASV High-Temperature Copper Voice Coil
  • Airflow cooling design


No con to be found.

4. Polk Audio DB+ Free Air Subwoofer

Polk Audio DB+ Free Air Subwoofer


Peak power handling: 1110 watts
Frequency response: 26-200 Hz
Sensitivity: 86 dB
Top-mount depth: 4-3/8″
RMS rating: 370 watts
Voice coil: 4-ohm dual coils

Polk Audio offers dual 4-ohm coils, which offer wiring flexibility. Polk DB is marine certified which makes it durable and capable of taking adverse weather conditions. It uses laser imaging to determine what combination of material creates the minimum amount of resonance. Polk audio uses dynamic balance technology in its audio components for richer, clearer, and more full-range sound.


  • Low profile space-saving design
  • Dynamic balance technology
  • IP56 marine waterproof rating


  • Baskets are steel coated, which makes them hazardous in water use.

5. BOSS Audio Systems P80DVC Car Subwoofer

BOSS Audio Systems P80DVC best free air subwoofer
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Max Power: 1000 Watts
Impedance: Dual 4 Ohm
Resonant Frequency: 42 Hz
Sensitivity: 88 dB @ 1 W/1 m
Voice coil: 4 ohm voice coil

Get rid of poor sound quality in your car with BOSS Audio Systems P80DVC Car Subwoofer. It has a treated paper cone that is more rigid and is capable of handling high power and functionality in comparison to other alternatives. Unlike rubber, foam is used as a surrounding material that provides clearer sound.
The material used to make voice coil, aluminum is remarkable for its low density and corrosion resistance. Aluminum is solid material and it has the ability to perform under both high compression and high tension conditions.


  • It is compatible with both 0.8 CuFt ported or 0.5 CuFt sealed enclosure.
  • These subs work efficiently with smaller enclosures.
  • Dual voice coil adds to the wiring flexibility.


  • Bass power is not adequate.

10-inch Alternatives For 8 Inch Free Air Best Subwoofer Under 300

If you are looking for higher bass response and more clarity, the 10-inch subwoofer is a good alternative. Here is a quick overview of 10-inch free air subwoofers.

  1. Skar Audio SDR-10 D4 10″ Car Subwoofer

Skar Audio best free air subwoofer under 300


Peak Power: 1200 Watts
RMS Power: 600 Watts
Frequency Response: 28 Hz – 300 Hz
Sensitivity: 82.5 dB
Voice Coil: 4 Ohm

Capable of enduring hard-hitting this 10-inch sub offers ultimate sound quality along with perfect low notes. Its high-temperature 2.5 inches 4 layers high-temperature voice coil product high punchy bass. This sub will provide you with a low-end bass response with its high roll foam surrounding.


  • Competition Grade Pressed Paper Cone
  • 2.5″ High-Temperature Copper Voice Coil
  • Advanced Air Flow Cooling System


  • No cons are to be found.

2. Kicker 10″ Free Air Subwoofer

Kicker 10" Free Air Subwoofer

RMS rating: 175 watts
Peak Power: (350 watts)
Frequency response: 30-500 Hz
Sensitivity: 86.27 dB
Impedance: 4 ohms

For cars with no space for subwoofer enclosure, Kicker subs are an ideal choice. They are marine waterproof but come with a steel basket, which makes them unfit for water. They offer low-frequency power with 4-ohm rugged impedance. It is perfectly designed for water adventure, but can also be used elsewhere.


  • 20 colour options
  • Humidity and corrosion resistant
  • Ceramic magnet eliminates sensitive navigation equipment interference


  • Makes a popping sound at high power

3. BOSS CH10DVC Car Subwoofer

BOSS CH10DVC best free air subwoofer

Max Power: 1500 Watts
Impedance: Dual 4 Ohm
Resonant Frequency: 38 Hz
Sensitivity: 84 dB @ 1 W/1 m
Voice Coil: 2”, Basket Structure

BOSS CH10DVC Car Subwoofer is a dual voice coil subwoofer, which makes it more versatile when it comes to wiring. It makes these subs are ideal for medium to high power applications. In such a value nothing can beat this subwoofer with its polypropylene cone and rubber surround.


  • Polypropylene cone
  • Butyl rubber surround offers quality sound
  • High-temperature voice coil


  • Volume is not adequate

Conclusion | Best Free Air Subwoofer

Setting your personal preferences as per your music choice along with where and how much you will be going to use it, you can carry on with choosing 8-inch free air subwoofer or 10 inches. Once you are done with your selection, make sure you are following the right instructions when it comes to installation. Combining all the important factors with personal preference you can add to the sound quality and convenience.


1. Can any subwoofer be free to air?

Any sub can be put into a free air configuration, which does not mean that it will give a good sound or not.

2. What are the high-hitting free air best subwoofer under 300?

Depending on the quality and features, these are some of the best subwoofers under 300;

  • JBL Stage810 – 8″ Car Audio Subwoofer
  • Infinity Kappa 8″ Car Audio Subwoofer
  • Skar Audio IX-8 D2 8″ Car Subwoofer

3. What is the difference between round and square subwoofers?

Square subs have more surface area that lets more air move freely unlike the traditional subwoofer, which is round. Whereas round subwoofers are generally better sounding because they are easier to control. A subwoofer offers better sound quality if they are controlled or handled in a good way.

4. Are 15-inch subs louder than 12-inch subs?

With all the other factors being controlled, a 15-inch sub will definitely be louder than a 12-inch sub. You can always feed more power to get more volume from a subwoofer. Especially if you are going to deal with low-frequency signals, more power can give you the best results.

5. Does a sealed or ported enclosure hit harder?

Depending on what you call “hit harder” performance may vary. In our experience, ported or sealed boxes, are louder in comparison to free air. They also offer punchy bass.

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