Car Subwoofers

Best 8 Inch Subwoofer 2021- Buyer's Guide

Mike Cross
Updated May 8, 2021
Best 8 Inch Subwoofer for car

When you’re in the market for a compact subwoofer, you need to consider a lot of factors for the best fit. While subwoofers come in many sizes, 8-inch subwoofers can give you that thumping bass you crave without taking up every last spare inch in your car.

I found Sundown’s Audio 8-Inch 500W RMS Dual 4-Ohm SA Series Subwoofer to be the 8-inch subwoofer available.

Overall, the Sundown SA Series model provided the best sound for its size, and some added features I loved. 

Of course, not everyone will be looking for all the bells and whistles – and there are cheaper models on the market as well. You may also want to look into different sizes, like a 6x9 car speaker. 

In this article, we’ll outline the ten best 8-inch subwoofers, what each is best for, and some of the pros and cons to consider before purchasing. 

Best 8-Inch Subwoofers on the Market

The following list should be helpful whether you’re looking for the best subwoofer overall, the best on a budget, or the best for a specific type of car. 

1. Sundown Audio 8 Inch 500W RMS Dual 4-Ohm SA Series Subwoofer - Best Overall

Sundown Audio has one of the best 8-inch subwoofers you can find. It has an RMS rating of 500 watts and is more sensitive than several other speakers on the market, ensuring you get the perfect booming thrum you expect from a subwoofer like this.

This isn't a shallow-mount speaker, so it requires 6.7 inches of depth for proper installation. However, because it's an eight-inch sub and not a 12 or 15-inch, it won't take up every last available millimeter of extra space you have in your car. 

Pros

  • Can handle a little more than 500 watts
  • Excellent build quality
  • Despite its size, it rattles your car's windows
  • Can sound like two ten-inch speakers

Cons

  • Extremely heavy at 27 pounds
  • Recommended for port boxes only

2. Kicker 44CWCD84 CompC 8 Inch Car Subwoofer - Best Bass

Kicker's CompC 8 inch subwoofer is a dual-voice, four-ohm subwoofer that gives you some flexibility with your wiring options. It has an RMS rating of 200 watts and a peak power output rating of 400 watts. 

This subwoofer performs at its best with a sealed or ported enclosure and requires at least 200 watts of power, along with a minimum mounting depth of four inches and 0.5 to 1.2 cubic feet of space for the sub boxes. You need sub boxes with a seven-inch mounting diameter for these speakers. 

Pros

  • Engineered specifically for an excellent thumping sound
  • Fits nicely in trunks and behind the front seats of many vehicle models
  • Superior to many OEM car speakers
  • Perfect for people on a budget

Cons

  • Requires drilling new holes in existing sub boxes
  • It might be too powerful for certain electric and hybrid cars

3. BOSS Audio Systems CXX8 8 Inch Car Subwoofer - Best Budget

BOSS is one of the better-known names in audio systems, and they make an 8-inch subwoofer that can withstand the wear and tear all speakers suffer when audiophiles like you use them. It has high levels of electrical and thermal conductivity and retains its strength at high temperatures.

It also has a stamped basket that absorbs and transfers a lot of the energy the subwoofer produces, reducing vibration in your car and giving you sharper, higher-quality sound.

Pros

  • Affordable
  • The small profile and reasonable price
  • Requires less "break-in" time than other subwoofers
  • Has a power rating of up to 600 watts, making it one of the most potent subwoofers at this price
  • Three-year warranty when purchased via an authorized dealer

Cons

  • Not suitable for DIY installation 
  • It might not work well for you depending on how complex and powerful a system you want

4. Rockford Fosgate P3SD2-8 Punch Series Shallow Mount 8 Inch Subwoofer - Best for Small Space

If you're looking for a relatively powerful subwoofer for a shallow space, Rockford Fosgate's P3SD2-8 might be the one you're looking for. They've specifically designed these to deliver a maximum punch in a minimum space. 

It's optimized for a sealed and vented enclosure, too, though a sealed enclosure will produce a better sound. And since Rockford Fosgate calls itself fanatics making audio systems for fanatics, you can trust that they understand your needs.

Pros

  • Spider-venting design system vents heat better than other venting systems
  • Requires less than three inches of mounting depth
  • Perfect for those who need to feel their bass
  • Works well in cars and SUVs

Cons

  • More expensive than comparable-quality subwoofers
  • Shallow mount means cones can't move as much, which can change the sound quality

5. JBL Stage 810 8 Inch Subwoofer - Best Factory Replacement

JBL produces OEM parts for some of the automakers, so if you're looking to replace a stock part, consider one of their 8-inch subwoofers. Not only are they inexpensive, but they can handle up to 200 watts RMS and 800 watts total, making them one of the most powerful 8-inch subwoofers out there.

They also work well with various amplifiers, giving you some flexibility when it comes to purchasing a new amp. 

Pros

  • Lightweight at just two pounds
  • Fits many existing factory setups
  • Is excellent for people who want better bass, but not super-heavy bass
  • The subwoofer can be pushed slightly beyond its RMS rating

Cons

  • May require some jury-rigging or total box replacement
  • May also need a custom bracket

6. Kicker 43CWR84 CompR 8 Inch Car Subwoofer - Best Control

Kicker is another well-known name in the world of audio systems, and this subwoofer is no different. Its dual voice coil gives you flexibility for wiring and, like other Kicker products, has stacked magnets for control and power handling. 

It has a 300-watt RMS rating with a 600-watt peak power rating, though it works best at a 400-watt setting in either sealed or vented enclosures. You also need a minimum mounting depth of over four inches, so it's larger than some of Kicker's other subs.

Pros

  • Solid-piece backplate and pole piece help thermal management
  • Requires slightly smaller mounting boxes than other speakers
  • Lends itself well to custom installations
  • May fit where OEM subs were

Cons

  • Requires more wiring than many people may want
  • Some of the glue used for it may give off an odor

7. Kenwood Excelon KFC-XW800F Shallow-Mount 8 Inch Subwoofer - Best Durability

Kenwood's Excelon shallow-mount 8-inch subwoofer has a carbon-fiber glass composite cone for resistance to wear and tear from heavy use and a removable gasket that works with its heat transfer system to keep the whole setup as cool as possible. 

It also has a super-linear spider mechanism that helps control its linear motion and dual magnet drive, and its aluminum-cast basket enhances the durability of the subwoofer's setup. It's also nice and shallow, requiring only 2.75 inches of depth for installation.

Pros

  • Better than OEM models in cars despite its shallow mount
  • This is an 8-inch subwoofer that can sound like a 10-inch
  • Lines up with several OEM mounts
  • Looks very nice for those who require good aesthetics

Cons

  • Has a peak output of 600 watts but is only rated for 50 to 150 watts RMS
  • Doesn't work very well with ported enclosures

8. Alpine SWR-8D2 8 Inch Car Subwoofer - Loudest for the Size

Whether or not you're familiar with Alpine, their SWR-8D2 is an excellent dual two-ohm subwoofer with a Kevlar-reinforced pulp cone, and a Santoprene surround for extra durability. It has high sensitivity, too, which gives you fantastic sound with less power usage.

This sub is a little different from others we've discussed in that it has a peak power output of 1,000 watts, but an RMS rating of only 150-300 watts. It's a very powerful sub for peak power, but its RMS rating puts it squarely in line with other popular 8 inch subwoofers.

Pros

  • Requires less depth than some competitors with similar subwoofers
  • Is one of the loudest 8-inch subwoofers on the market
  • Can sound like larger speakers with the right box
  • Is perfect for rock, metal, rap, and hip-hop 

Cons

  • Questionable durability
  • Heavy at 10.5 pounds

9. Polk Audio DB+ 8 Inch SVC Marine, ATV & Car Subwoofer - Best for Multiple Vehicles

What happens if you want to install an 8-inch subwoofer on something other than your car? Polk Audio's subwoofer works for marine and ATV applications in addition to cars. So no matter where you are, you can have your chest-thumping bass with you.

It uses a dynamic balance technology to give you a more expansive sound range and is rated at 250 watts RMS. Its low profile allows you to install it in your car doors or other tight places as well.

Pros

  • Resistant to dirt, water, salt fog, humidity, and more
  • Very inexpensive for its quality
  • Works well with other brands' components
  • Reasonable weight makes it suitable for car doors

Cons

  • Rattles loudly with OEM amplifiers
  • Doesn't come with a grill

10. Infinity Kappa 8 Inch 800 Watt Car Audio Subwoofer - Best Audio Versatility

If you're looking for a powerful subwoofer, you've found one of the best 8-inch subwoofers out there. Infinity's Kappa subwoofer has something they call Selectable Smart Impedance, which allows you to switch between two and four ohms. You get outstanding versatility with this sub.

This one has 1600 watts peak power output with 400 watts RMS for those who want a high-powered sub. You get that bone-rattling, heart-thumping bass beat that you want from a high-quality subwoofer.

Pros 

  • Excellent for people who don't want to fill up their entire trunk
  • Adding a second Infinity Kappa subwoofer only adds to the sound's quality and thrum
  • Lightweight for such a deep subwoofer
  • Can use it in a port box or a sealed box

Cons

  • Can seem overwhelming with a port box
  • Doesn't work well in small cars

What to Look for When Shopping for 8 inch Subwoofers

You have several different things to consider when looking for the right 8-inch subwoofer, including your budget, your reason for buying one, specs and features, available space, your type of amplifier, and more.

Features, Specs, and Performance

What do you want your sound system to do? Many times, we look at audio systems and think, "That looks good, I'll get that," only to be disappointed with its performance later. 

If you want to compete in SPL competitions, the system you need is very different from what you need to simply spice up your car's factory system. There are lots of other reasons people want these kinds of audio systems in their cars, too. 

Bigger, higher-powered, and even dual-voice aren't necessarily all better subwoofers. This goes back to what you want your system to do. If you're going for the best booming sound possible, then yes, you want a subwoofer with high RMS power that your amp can handle. 

Other specs to consider include:

  • Frequency range: A subwoofer's frequency range tells you how low it can accurately go. Keep in mind that the subwoofer's enclosure and other variables will affect that.
  • Sensitivity: The more sensitive a subwoofer is, the less power it requires for higher volumes.
  • Enclosure or box: The type of your box and whether it's sealed has a significant effect on the sound. A sealed box produces a deeper, more accurate sound. Ported boxes give you more volume. 
  • Impedance: A subwoofer's power rating is calculated at a particular impedance. You must make sure your system's impedance matches that of your amplifier, including that of your subwoofers.

Subwoofer Size

Subwoofers come in many sizes with three profiles: Regular, shallow-mount, and slim. Since we're focusing entirely on 8-inch subwoofers, you don't have to worry about diameter. However, you do have to think about its depth and the size of its box. 

Before you do anything, measure the height, width, and depth of the space in which you plan to install your subwoofers and their boxes. From there, you can determine what profile subwoofer you need. 

Budget

Most of us find ourselves budget-constrained when it comes to purchases like this, so you're probably thinking about the highest-quality subwoofer you can afford. However, unless you already have an amplifier and the necessary electrical upgrades in your car, you'll have to take those costs into account as well. 

The one thing to remember when it comes to the budget is that more expensive doesn't always mean higher quality. If you do some thorough research and shopping around before committing yourself, you'll get a system within your budget that performs how you want.

Amplifier Compatibility

If you already have an amplifier, you need a subwoofer that matches its impedance and voice coil configuration that fits your amplifier's power. If you don't yet have an amplifier, you need to ensure that everything you buy matches your amp's requirements.

For instance, if you have an amp with an RMS rating of 500 watts at two ohms and you have a 500-watt subwoofer, you should make sure you can wire it at two ohms. 

Also, if you have, say, two subwoofers with dual voice coils at four ohms, the final impedance at your amplifier is either one or four ohms depending on how you wire things.

Be sure to read the specs before you buy, so you don't wind up with components you have to return.

Final Thoughts

After all my research, I feel that the Sundown Audio 8 Inch 500W RMS Dual 4-Ohm SA Series Subwoofer is the best 8-inch subwoofer you can find.

The Sundown gives you incredible sound while still going for a reasonable price. Its sensitivity and power output level give it excellent sound with low power use, and its construction makes it heavy but not impossible to lift.
You do have to do your research carefully before purchasing, so the subwoofer you pick will serve you well. Once you know what you need, you can start shopping here.

Mike Cross
Life is too short to drive with stock audio

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