Sealed subwoofer boxes conveniently include all of the components in one enclosure. With their fully closed design, these devices can effectively produce clear and powerful bass, particularly in vehicle audio systems.
There are several ways to make a sealed box louder, but the most effective way is to increase the power supplied by the amplifier. This will allow more bass frequencies to be produced through the speakers. Alternatively, adjusting the sub position is an easy way to increase the box’s volume.
There are many benefits to using a sealed box subwoofer. Most notably, they tend to produce better-sounding bass than their ported counterparts but being enclosed makes them naturally quieter.
In this guide, you’ll learn the most effective ways to make a sealed box louder so you can enjoy more volume from your subwoofer without compromising on sound quality.
1 – Upgrade Your Amplifier
One of the most effective ways to make a sealed subwoofer box louder is by ensuring that the amplifier you pair it with is compatible and powerful enough. If the sub and amp are not a good match, you will experience decreased overall volume.
Check the specifications of your sealed box to see how many ohms it is rated at and how much power (watts RMS) it can handle. Once you have these numbers, you then need to check that it matches the amp’s capabilities.
Amplifiers are rated in terms of watts RMS into a specific amount of ohms, so it is easy to see whether they match up with the specs of your sealed box.
There’s a common misconception that a more powerful amplifier automatically guarantees more volume from a sub when in fact, it’s more important to ensure they’re well matched. Otherwise, the additional power will be rendered useless.
Upgrading your amplifier to one suited to your sealed box’s specs is a simple and effective way to increase your good system’s volume and sound quality.
2 – Switch the Position
If you’re familiar with the basic principle of acoustics, you’ll know that the position of any speaker dramatically impacts the way it sounds. This includes its tone, prominent frequencies, and loudness.
Placing your sealed box in a position where the included subwoofer speakers are pointing directly at a surface is going to result in the vibrations being deflected or, even worse, dampened.
This may cause the volume to seem lower because less of the bass reaches your ears before it is reflected off the various surfaces in your car or in your home audio setup.
To figure out the optimal position for the sealed box, you should choose an appropriate listening point in the room or car, then play the same song at the same volume through the sealed box speaker and monitor its loudness.
If it appears louder in a specific place, this is likely the best acoustic position for the sealed box to be kept.
3 – Adjust EQ Settings
If your sound system has onboard equalization, which it more than likely will, you can adjust these settings to increase the prominence of specific frequencies produced by the sealed box.
EQ can be used in two different ways – adaptive or reductive. The former involves making certain frequency bands louder, while the latter involves reducing specific frequencies to make others stand out more clearly.
A sealed box most commonly houses a subwoofer; therefore, you might find that reducing some of the upper midrange and high-end frequencies of your sound system allows the bass frequencies produced by the sub to be more audible.
EQ won’t make your sealed box noticeably louder, but it can help you to create more separation between the frequency bands, which may improve the clarity of the sound.
A more precise sound often results in the illusion of it being louder, as your ears can focus on the individual sounds more easily.
4 – Use Polyfill
Although I’m aware that this may sound like a strange suggestion, one of the most effective ways to increase the loudness of a sealed box is by filling it with a material known as polyfill.
Polyfill is also known as wadding, it is a soft synthetic fiber that is commonly used to stuff pillows, duvets, as well as for acoustic purposes.
A reasonably inexpensive material, polyfill is made from polyester. It can be effective at making your sealed box louder because it can cause the vibrations within the enclosure to slow down, resulting in them sounding clearer and more pronounced.
If the sound frequencies are free to bounce around inside the sealed box, this could be why you’re struggling to hear them. Bass traps and problem frequencies may occur, canceling one another out.
By filling the sealed box with polyfill, you ensure that the vibrations will be absorbed, which results in minimized distortion and better separation between the various frequency bands.
Acoustic treatment is commonly used not only to prevent sounds from leaving a space but also to improve clarity within a space.
Therefore, polyfill is an excellent option for making your sealed box sound better, clearer, and hopefully louder.
5 – Switch to a Bandpass Enclosure
If you’ve tried all the above methods and you still find that your sealed box seems too quiet, then it might be worth considering switching to another type of subwoofer box. The three types you can choose from are:
Of the three, sealed boxes are generally considered the quietest. They do, however, produce a tighter bass sound which is why they are popular.
Vented boxes can sound boomy, mainly if they’re used in a small space. Therefore, I’d recommend considering switching to a bandpass box if you want to increase your volume considerably without compromising on tone and sound quality.
A bandpass enclosure differs from a sealed box in that it includes two separate sections. The first section is vented, while the second section is sealed.
This makes them an ideal middle ground between the tighter sound of a closed box and the more open, louder sound of a vented box. You experience an increase in loudness while retaining some of the definition that a closed box offers.
There are many great bandpass subwoofer boxes to choose from, like this excellent option from JBL.
How do you increase bass in a sealed box?
The most effective way to increase the amount of bass produced by a sealed box is by filling it with an absorbent material, such as polyfill. This will help to absorb any problem frequencies, making the bass sound clearer and more prominent.
Can a sealed subwoofer handle more power?
The power handling capabilities of a subwoofer box does not depend on whether it is sealed. Any subwoofer box can have higher power handling capabilities; however, it must be matched with the right amplifier.
Does the size of a sealed box matter?
The size of a sealed box is directly related to the sound it produces. If you play audio through a larger box, then there is more space for the vibrations to resonate and reflect, which will cause a louder sound. Smaller boxes will sound tighter with less volume.