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How to Choose the Best Subwoofer for Your Car?

Choosing the right subwoofer for your car can seem daunting, but it doesn’t have to be! With some research and helpful tips, you can find the perfect subwoofer to get your car shaking. 

But how do you choose the best sub for your ride with all the different options on the market? Let’s find out.

To choose the best car subwoofer, check its size, cost, power handling (RMS), and sensitivity. Continuous power (RMS) is the most important factor for the subwoofer to create a strong and deep bass for any car. If space in the vehicle allows, choose either 12″ or 15″ built into a designated box.

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Tip: There are many factors to consider when choosing the right car subwoofer for your needs.

By thinking carefully about these factors and researching different brands and models, you can find a quality subwoofer that fits your budget and meets all of your audio needs.

One of the manufacturers whose subwoofers are worth considering is SKAR (link to Amazon). Skar offers subs from 6.5″ up to 15″ and a large selection of ready plug-and-play enclosures.

In the article below, I will go into more detail about different types of subwoofers and how to choose the right one for your car.

What to Look For in a Subwoofer?

When choosing a subwoofer, you should consider four main factors:

how to choose right car subwoofer

#1. Power Handling (RMS)

This is the most critical factor to consider when choosing a subwoofer.

The higher the RMS power ratings, the more powerful the subwoofer. If you are buying a new subwoofer, installed car speakers should roughly tell you how much power you need, meaning that the subwoofer alone should have equal or greater RMS than all other installed speakers.

For example, if you have two 100-watt speakers, you’ll need a subwoofer with at least 200 watts RMS. The peak power is the secondary parameter, but the broader difference between the RMS ratings and the peak wattage, the better.

#2. Size

The size of the subwoofer will determine how much space it will take up in your car. If you have a smaller car, you may want to choose a smaller subwoofer so that it doesn’t take up too much space.

On the other hand, if you have enough room and want a solid boomy bass, choose a larger 12″ or 15″ subwoofer.

#3. Sensitivity

Sensitivity measures how much bass the subwoofer can produce from a given amount of power at a certain distance.

The same as for standard speakers, the subwoofer with a sensitivity of 88 dB will be twice as loud as one with 85dB. If you want to hear the bass at a larger distance from the car, choose the sub with higher sensitivity of at least 87dB.

Higher sensitivity also means that you need less amplifier power to deliver the same SPL as for the lower sensitivity rating.

#4. Cost

Subwoofers can range in price from around $50 to over $1000. The cost will depend on the factors mentioned above, as well as the brand and quality of the subwoofer.

If you’re on a budget, you may want to choose a cheaper subwoofer so that you don’t have to spend too much money. However, remember that you usually get what you pay for, and a cheaper subwoofer may not have as good quality as a more expensive one.

What Subwoofer Size Do I Need for My Car?

The subwoofer size depends not only on the acoustic space in the car but also on the amplifier, wires, and of course, the bass effect you want to achieve.

You can choose from the 6.5″ up to 18,” depending on the audio set-up and your goal.

6.5″, 8″

With limited space, you may need to look at smaller subs, either 8″ or 6.5″. Those are cheaper and may be the only option to get the bass you want without giving up too much trunk space.

Skar Audio EVL-65 D2 6.5" 400 Watt Max Power Dual 2 Ohm Car Subwoofer

If you choose a smaller sub, pay attention to the power handling and ensure it can take the power your amp can dish out.

The smaller subwoofers do not have the high-frequency response, but they still can sound good, like the Skar EVL-65.

10″

10″ speakers can be very fast, which means they play clean and deep bass, but it’s hard to achieve huge air pressure from one 10″ woofer.

Smaller woofers however, give you more freedom in choosing the right place for them. In addition, they are, in most cases cheaper and do not require a “power plant” to play efficiently.

The golden mean can be a 12″ subwoofer. However, the tricky part is that 12″ subwoofers are the most popular on the market, so you can pick probably every type of speaker you can think of.

Several years ago, I was a little disappointed about the bass quality from my new 12″ when I compared it to the older 10″ woofer.

Fortunately, the problem was not in the speaker itself but its power. It just required twice as big an external amplifier compared to what I had, and I reduced the low pass filter frequency.

After these changes, the bass was outstanding and still plays today.

12″

When it comes to the 12-inch subwoofers, they have one massive advantage over all other sizes.

They are a mix of 10″ speed and, at the same time, can produce a deep, strong bass like 15″. They can also create fantastic sound air pressure.

To achieve what you want and not be disappointed when choosing a car subwoofer, you must have a suitable enclosure, a good quality amplifier, and top-quality wires, all of which need to be set up correctly.

15″

Although the 15″ woofers play the lowest tones, they are sometimes slow and need powerful amplifiers. Also, enclosures for the 15″ speakers are, in most cases, not fitting in many cars, but their advantage is strong and deep bass.

When you have all the right equipment correctly set up, you do not need more than one subwoofer, and you will be delighted with 15″.

18″

The 18″ subwoofers are the biggest ones and can create enormous sound pressure.

They need a lot of amplifier power and a large enclosure, but if you have all that, one 18″ subwoofer can make your car sound like a club on wheels.

Skar Audio ZVX-18v2 D2 18" 3200 Watt Max Power Dual 2 Ohm SPL Car Subwoofer

This is true, especially in the case of a monster like Skar ZVX-18v2, which, when wired at 1 ohm, makes exceptionally high sound pressure, but to do that, it needs to be supplied with plenty of power.

Different Types of Car Subwoofers

The enclosure type depends on the speaker’s parameters, car design, and preference because every type produces slightly different sounds.

When choosing a car subwoofer, you will find three popular types of bass boxes, but what are the differences between them?

Sealed Enclosures

Sealed subwoofer enclosure boxes are great for small spaces, and they can produce precise, high-quality bass like this small Kicker 43TCWRT84 with its compact design.

Thanks to the construction that makes the sound punchier, you will not hear any “extra” unwanted sounds like a bass reflex. 

Although subwoofers with sealed enclosures produce an excellent bass quality, you will not be able to tune them, which means they cannot achieve the lowest frequency range, similar to those coming out of ported boxes.

The only way to “tune” a sealed box is to change its size for the same speaker, which means you can manipulate the responses of the same speaker after placing it in different boxes.

The basic rule for choosing the enclosure’s size is that the bass speaker in the smaller box will play higher, while the same speaker in the larger box will play slightly lower frequencies.

Sealed enclosures are also safer for speakers, especially their voice coils. The extreme cone movements are more controllable and limited by compressed-in-the-box air that works like a spring.

The air in the sealed enclosure is more resistant, which means the cone does not have much free movement.

To be fully efficient, sealed boxes require more power than open constructions. Unfortunately, not every amplifier can meet this requirement.

Another advantage of sealed boxes is their straightforward design and relatively low costs.

Bbox Single 10 Inch Subwoofer Sealed Enclosure - Car Subwoofer Box & Enclosures - Premium Subwoofer Box Improves Audio Quality, Sound & Bass - Red & Black Spring Terminals - Charcoal

For sealed enclosures, it is recommended to fill them with acoustic foam, but you will find that not all producers are soundproofing their boxes.

You may be wondering if the sealed enclosures need filling.

Technically yes, the sealed enclosures should be filled with acoustic foams because acoustic waves do not like bouncing off flat surfaces. Because of that, in many boxes without soundproofing, you will find a back wall tilted, but this is not enough.

It is worth considering filling your subwoofer with acoustic foam if you want to hear the highest sound quality rather than just having a loud car.

Ported Bass Enclosures

Ported enclosures (either vented or bass-reflex) have a completely different characteristic than sealed boxes.

They produce louder but much less accurate bass, so if you want to go extremely loud and see a door in your car or roof vibrating, you should choose ported bass enclosure.

The advantage of the ported enclosures is an increased lifetime of the drivers because of better ventilation.

The fresh air going back and forth through the channel is cooling the magnet, which is less likely to overheat than inside the sealed boxes, where the speaker’s pressure is higher, increasing air temperature.

Ported bass enclosures are also larger; because of how sound waves move inside the boxes, they are also deeper.

Because of their size, they may not be the best option for smaller trunks with insufficient room in front of the speaker. In the case of small sports cars, ported boxes may not even fit inside.

Placing a too big subwoofer for the trunk was a mistake I made many years ago with one of my first subwoofers. By then, I had little idea about choosing a car subwoofer, and I picked something a little too big…

It fitted to the car correctly, but the space between a cone and trunk lid was barely three inches, so you can imagine what happened when I put the volume higher. And in the end, the entire car was rattling.

It took me a lot of time and effort to isolate the back of the car with anti-vibration foam, and still, I could not use its full power. Well, lesson learned…

These types of enclosures are straightforward to tune. However, they are more efficient when appropriately designed, meaning you will need a less powerful amplifier to achieve the same volume as the sealed boxes.

Skar Audio Single 12" 2500W Loaded EVL Series Vented Subwoofer Enclosure | EVL-1X12D2

The port tuning is critical to maximizing the subwoofer’s output capability. In addition, ports allow subwoofers to reproduce the low frequencies commonly used in Rap and Hip Hop. 

But what is the port tuning?

Port tuning is nothing else than designing the port (channel) inside the enclosure, allowing your subwoofer to strengthen specific frequencies.

For example, when you make your enclosure and want to achieve the strongest bass at 54Hz, you must calculate the port’s exact location and size.

Ports can have different shapes, from typical round plastic called bass-reflex to the form of triangular or square, and cannot be placed anywhere in the box.

Bandpass Subwoofer Enclosures

When choosing a car subwoofer, you will find the most complicated design in the bandpass enclosures. In simple words, I can say that they are a combination of both sealed and ported bass enclosures.

Bandpass enclosures are an excellent choice for cars with closed trunk areas like sedans, where you need a lot of energy to transfer quality bass to the cabins, so if you drive a VW Passat or BMW 5 series, this is the box type for your car.

The bass from bandpass boxes significantly outperforms other types of enclosures, and it focuses on narrower low-frequency sounds. The best bandpass boxes I have found are from SKAR.

The frequency peak is usually set around 60Hz, which can be perfect for Rap music, but other music types like Pop or Rock will not benefit from this construction.

Although the most common 60Hz, you can fully customize the frequency peak when ordering a custom box, it is up to you in which area you want to make the “bass kick.”

However, you must remember that the bandpass enclosure should be designed as a part of the complete car audio system rather than a single box just added to any speakers in your car. 

Dual Electronics BP1204 High Performance 12 inch Car Audio Subwoofer in a Tuned Bandpass Enclosure with Blue illumiNITE LED illumination and Plexiglass Viewing Windows and 1,100 Watts of Peak Power

There are two types of bandpass boxes design:

  • Single reflex, with the speaker placed in the sealed subwoofer box, but the front area looks like a vented box.
  • Dual reflex, with one speaker, mounted in the middle of the big box with two ports. One in the front of the speaker and another at the back of the speaker.

The difference between these two types is not just the number of ports they have but also the size and type of bass they can produce. 

Remember, there is no such thing as a universal bandpass box. Instead, you must customize bandpass boxes for each type of speaker and car in which you will use them.

The design of these most complicated boxes has to be perfect, meaning you have to consider the speaker type, size of the trunk, and acoustic in the car, to name a few.

Otherwise, you will not achieve more than a poor bass experience in the vehicle, even with the highest quality driver. Well, unless your only priority is to create thunders in the car, completely ignoring music quality.

Bass Tubes

Bass tubes are known for their narrow frequency response, which means they can be really large but not so efficient at the same time.

They can produce a loud “boomy” bass, but its quality is low. So if you are looking for a solution that will give you a high-quality clear bass, bass tubes are not the best choice.

MTX Audio RT8PT Universal Powered Subwoofer Enclosure

They have, however, an advantage, and that is their cost. Tubes are cheaper than the typical bass enclosures; in most cases, they are active, so you do not need an amplifier.

They are straightforward to install and can be usable with a simple car sound system to increase overall dynamic, but something is missing, and this missing part is the quality of the bass.

If you want a simple boost to your car audio, Amazon has a wide selection of bass tubes.

What Is Free Air Subwoofer?

When your car has a small trunk, or you do not want to use the entire available space for the enclosure, you may choose a free air subwoofer.

The free air subwoofer is a speaker that does not require to be installed in the enclosure. Typically, free-air subwoofers are installed in the back seat or the rear deck.

Free air subwoofers work best in sedan cars and are a cheaper option than the subwoofers in the enclosure. Nevertheless, you will need to add a baffle to the rear deck or back seat, depending on the place you choose for the subwoofer.

Installing a baffle that will hold your subwoofer is mandatory because construction has to be stable. You cannot just bolt a 10″ powerful speaker to the plastic deck. It will simply not work.

High-Powered Free Air Subwoofer - Impressive Bass Response, Low-Resonance Frequency Output, and Power Handling: 300 Watt PEAK / 150 Watt RMS with Car Subwoofer Size: 12.0 inch - Lanzar DCTOA124

There are hundreds of different models to choose from when talking about speakers, and the most challenging part is selecting the right one.

When choosing a free-air subwoofer, you need a powerful speaker with a firm suspension.

Remember also, when you install a free air subwoofer, the whole trunk needs to be correctly sealed because it will become a large enclosure.

If you want to achieve a clear quality bass, your car should not have free air movement between a trunk and a cabin.

Do I Need an Active or Passive Subwoofer for My Car?

Active Subwoofers

Active subwoofers (also known as powered subwoofers) have relatively simple built-in amplifiers. As a result, active subwoofers are usually less powerful and work in a narrower range of frequencies.

Still, they are smaller and cheaper than passive subwoofers, for which you need to purchase an amplifier and make more complicated wiring.

Cerwin-Vega VPAS10 10" 2Ω 550W Max / 200W RMS Powered Active Subwoofer Enclosure + Bass Knob

The two main types of active subwoofers:

  • Under-seat subwoofer is a flat box with a speaker that will fit into a small space below your seat.
  • Another type of active subwoofer is the spare wheel subwoofer designed to fit in an extra wheel space in your car. 

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

Both types have a straightforward installation and do not require additional equipment. However, they usually do not produce a strong low bass.

Active subwoofers can be a good option as an addition to your factory audio system, without other modifications to your car audio.  

Passive Subwoofers

Passive subwoofers (unpowered subwoofers) are either speakers installed in the enclosures or free air subwoofers that do not have amplifiers.

They offer much better quality sound, and you have a choice to combine many different amps with even more speakers to achieve your desired bass effect.

Is a Single Voice Coil or Dual Better?

The subwoofer with a dual voice coil offers more wiring options than an amplifier, thanks to possible multiple impedance options.

The number of voice coils does not make a woofer louder and does not affect the power or frequency response, however, it may require more power from the amplifier if you use a low impedance subwoofer.

With a single voice coil subwoofer, you have only one set of wiring terminals and one connection option.

Dual voice coil subwoofers are usually more expensive but offer more flexibility regarding wiring and more options with the amplifier selection. The amp can be either 2 or 4 ohms depending on the connection type.

How Many Subwoofers Do I Need in My Car?

When it comes to car subwoofers, not always more means better. You can achieve the same effect when choosing the right subwoofer as you would do with two drivers.

If you decide to install two subwoofers, remember that they have to be the same. Otherwise, they can fight against each other, which is the last thing you want to experience.

Many cars do not have trunks big enough for two subwoofers. Sometimes even dual enclosures are too big and will not play efficiently. It does not make much sense to spend hundreds of dollars on two subwoofers and, at the same time, not use their power.

A much better option is to get one, even when smaller, but build it into a perfectly calculated box and power it up with a high-quality amplifier. It will bring you real satisfaction.

For the smallest woofers, it is worth installing two or more. There are many pickup trucks with four or more small 6.5″ subs under the back seat in the dedicated enclosure, so the number of drivers depends on the space and personal preferences.

What Is the Best Subwoofer for Small Car?

If you have a smaller car, choosing a smaller subwoofer might be a good and, in many cases, the only idea.

A 10-inch subwoofer might be too big and will not fit into a smaller car. A good option would be an 8-inch subwoofer or a 6.5-inch subwoofer placed in a single box.

BOSS Audio Systems BAB10 Amplified Car Subwoofer - 1200 Watts Max Power, Low Profile, 10 Inch Subwoofer, Remote Subwoofer Control, Great for Vehicles That Need Bass But Have Limited Space

Such designs are not large and do not require a big powerful amplifier, and if your trunk space is really limited, you can use a flat active underseat subwoofer, for example, Boss BAB10.

How to Break in a Car Subwoofer?

It is recommended to break in a brand new subwoofer, especially the high-end types.

When a woofer works at the beginning at a reasonable volume, all stiff elements will fit each other, especially cones with spiders and suspension.

You will not damage subwoofers without a break-in, but by doing so, they will have an extended lifetime, improving their bass.

The best way to break in the subwoofer is to use a frequency of about 30-60 Hz and set the volume so that you can hear it but not too loud. You should do it for at least 12 hours with recommended up to 24 hours.

Conclusion

There is no easy answer to the question of how to choose the best subwoofer for your car. It all depends on many factors below:

  • Type of your car and how much space it has for the subwoofers
  • Where in the vehicle will a subwoofer be located
  • Which music type do you listen to
  • What kind of bass effect do you want to achieve?
  • Do you need quality bass or just loud “booms?”

If you choose a smaller subwoofer, it will take up less space in your car and will not require a big and powerful amplifier. If you select a bigger subwoofer, it will need more space but will provide better deeper bass.