18 VS 21 Inch Subwoofer: Characteristics Explained!

It all comes down to inches when you want to be precise while purchasing a subwoofer. Yes, inches do matter, in case you were wondering. However, your criteria do as well!

So, what’s the difference between an 18 vs 21 Inch Subwoofer?

Between 18” and 21” it is clear that 21” subwoofers are larger in size and higher in price. About the bass quality, the 18-inch subwoofer is less powerful than 21”. the 21” subwoofer’s energy usage is higher. Compared to 18’’ subwoofers, the 21’’subwoofer is more prone to distortion and is heavier.

If you like the overview described in the nutshell here, then wait! We have a whole segment on this to make you clear about each and everything about 18 vs 21-inch subwoofers. So what are you waiting for? Follow along to learn everything!

Quick Overview

The subwoofers with 18-inch drivers are ideal for listening to music both outdoors and indoors. Because the basses aren’t as deep as 21 inches, the sound quality is better in enclosed spaces. 

18 vs 21-inch subwoofers are quite similar to how we differentiate 15-inch subwoofer from 18-inch. For both open and closed locations, there is a lot of controversies. Regarding 18-inch versus 21-inch DJ subwoofers

For party and industrial use, however, the majority of consumers favor 18-inch subwoofers. Over 21-inch subwoofers as 21” are heavier to move.

You might be wondering, are 18-inch subwoofers good? Or is it the 21-inch subwoofers that keep the party going!

Let’s have a look at a quick overview of why there is lot of debate over these two subwoofers:

Features18-inch Subwoofer21-inch Subwoofer
Distortion TendenciesHigherLower
WeightAround 32-64 IbAround 115 Ib
Sound QualityGoodBetter
PriceMore Budget-friendlyHigher

Now you know what’s the main overview here. Let’s dive into the more detailed comparison to understand better which one is worth buying.

18 vs 21 Subwoofer: Detailed Comparison

After the quick overview of 18 vs 21 subwoofers, it is time to dive into the depth of the details. So without any further ado, let’s get started-


The size clearly reflects the weight. Yes, you guessed it right. As an 18” subwoofer comes in a more compact size, it weighs less than a 21-inch subwoofer. Though both of the subwoofers are quite heavy. But 21 inches are not easily portable and heavier to move at all.

Source: wooferguy.com

The 18-inch subwoofer weight should be around 32-64 Ib. And on the other hand, a 21-inch subwoofer weight should be around 115 Ib. So it’s very clear that an 18” subwoofer is easier to move and use in different locations.

Winner: 18 inches Subwoofer.

Area Coverage

If you’re searching for a speaker for an outside performance, an 18-inch subwoofer is the way to go. 

Subwoofer speakers with an 18-inch diameter may cover a huge area (as in a nightclub, theater, concert, or even a stadium!). There are also some subwoofers adjustable to bose car system. 

This is a fascinating fact! An area of about 34000 square meters may be covered by a 360-degree arrangement of 18-inch subwoofer drivers. This is almost the same size as a football stadium.

Here are some great 18 inch subwoofers you can try:

These are the best of the best in the market right now. Up the beats in your car using these car subwoofers.

There’s nothing wrong with 21-inch woofers, but the sub boxes are too big and heavy to transport for portable audio purposes, and they may not pass through doors or into automobiles as easily. 

But there is no doubt that a 21” has more area coverage power than an 18” subwoofer. In general, it is recommended 21-inch woofers for installation in nightclubs or other locations where they won’t be moved frequently and where tremendous low bass is needed. 

They should also be used to accompany other smaller subwoofers that can cover the upper bass frequencies with more precision and efficiency while the 21s handle the rumbling between 20 and 60 Hz.

Winner: 21 inches Subwoofer.

Source: emaudio.com


It’s natural if you’re perplexed by the different subwoofer sizes. Surprisingly, consumers struggle to choose between front-height speakers and surround rear speakers. And it isn’t always the case that the bigger the greater. 

Subwoofers are available in a variety of sizes. Big woofers are typically 12 inches, 18 inches, or 21 inches in diameter.

In the case of the comparison between 18” and 21” subwoofers, the 21” is massive in size and obviously bigger than an 18” inch subwoofer. It is more powerful in sound quality and has better area coverage. 

But also, as it is bigger, it comes along with heavier and more difficult-movement problems.

Winner: 21 inch Subwoofer.


Both 18-inch and 21-inch subwoofers may be set to generate the lowest detectable frequencies. As effectively as possible, while the 21s will be louder at these extremely low frequencies. 

The bigger a subwoofer speaker is, the heavier its membrane weighs, and therefore its inertia increases, potentially affecting sound accuracy and introducing a “laggy” impression. 

As you increase the frequency, the frequency response of a larger woofer goes off faster than that of a smaller woofer, therefore 21-inch woofers may not be optimal for the upper bass or low mid frequencies.

However, for a small jazz club, an 18′′ or even a 15′′ sub may sound much better than a 21′′ subwoofer.

Winner: 18 inches Subwoofer.


Since 18-inch subwoofers are the most regularly used woofer size in most industrial applications, they are produced in larger quantities, resulting in lower prices. So, 18 inches subwoofers are more budget-friendly in comparison with 21 inches subwoofers.

Winner: 18 inches Subwoofer

Our Recommendation

After judging all the noticeable details, I would recommend purchasing an 18” subwoofer. Since there is not much difference in performance between 18” and 21” subwoofers. But the size and weight can be a big issue here.

Also, the 18-inch subwoofer price offers a much better deal. It is good for both indoor and outdoor operations. You can have it for a nightclub as well as industrial operations.

So, seeing all the factors our recommendation will be to go for an 18” subwoofer. 

Source: ridebass.com

Although, at the end of the day the decision will be yours. So make your decision wisely according to all the requirements you need to match. Good luck!


Are 20-inch subwoofers harmful to your health?

Since the pistonic motion of such a wide surface area is difficult to regulate, subwoofers with 15-, 18-, and 20-inch drivers are more vulnerable to boominess and distortions than subwoofers with 10-, 12-, or 13-inch drivers acoustically.

What is the optimal size subwoofer for low decibels?

For low-to-medium volume use, I want the greatest sound quality available. It is heard that an 18 inches subwoofer can always be performed at low decibels and yet still produce superb bass definition and richness of sound, but a 15″ subwoofer requires significantly more power to attain the same level.

What are the differences between a large subwoofer driver and a compact subwoofer driver?

A large subwoofer is more difficult to manage and does not guarantee heavier bass than a compact subwoofer. The bass produced by a subwoofer speaker is just theoretical. The larger the driver, the larger the amplifier current & magnetic energy are required to power the piston action.


Now you know everything about how to differentiate between an 18 vs 21 inch subwoofer. Choose wisely what will be better according to your requirements.

Hopefully, this article helped you to compare these two subwoofers thoroughly. This was all for now. All the best on your subwoofer purchase! 


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