How to Make Subwoofers Louder Without an Amplifier

Norvan Martin
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If you like loud music and powerful bass like many of us, you may be considering buying a high-quality amplifier. While that will certainly do well to improve bass performance, amplifiers can be expensive.

Instead, there are simple steps you can take to improve your bass performance and increase bass output before buying an amp.

You may find that you don’t need an amp at all. Read on for some easy ways of making your subwoofers louder without an amplifier.

Before we get into this guide, you may also want to check out our article on the best subwoofer and amp combos to make it very easy to make your subwoofer louder just with the setup.

1. Position the Subwoofer Properly

You’ll be surprised by how much of a difference the positioning of the subwoofer can make. The position of your subwoofer greatly influences the volume of bass that will flow through the room. Speaker and subwoofer placements are always important.subwoofer placement no amplifier

Typical subwoofer placements are either in the center of the home theater setup or in the corner. In general, we recommend placing the subwoofer in a corner. This is an easy way of getting up to six decibels of bass boost without an amplifier.

However, be sure to leave about 3 inches from the walls. This distance requirement is more important if you are using a rear-ported sub.

Also, you can experiment with moving the subwoofer to different locations in the room. That is actually the most important tip here. Ensure you do not place it at the same distance from the two walls. Putting your subwoofer in an asymmetrical position relative to the walls will get a much louder bass output.

Finally, if your home theater room is small, here are some speaker placements for small rooms with your couch against the wall. Additionally, a good option is to place your subwoofer behind the couch. On the other hand, a bad option is to place your subwoofer under the couch.

2. Tune Your Subwoofer Properly

Many people max all their sound system’s controls to make the subwoofers blast with louder and clearer audio.Tune Your Subwoofer Properly

However, if you have a substandard system, a massive, low-frequency boost is likely to put much strain on the network. So, tune your unit controls correctly and listen to the output to confirm whether you are getting a more precise, louder sound.

3. Adjust Crossover and Phase Setting

Subwoofer crossover and phase settings are very important factors for the proper functioning of your subwoofer.

For your subwoofer to produce better bass, it must be in phase with the entire sound system. Use the single-phase switch or variable dial that comes with the subwoofer.

Adjust the setting until you realize the desired bass quality. Most of these dials are continually variable or in some cases will offer a 0 and 180-degree position.subwoofer crossover and phase settings

Check your crossover settings as well. It works together with phase to give you the right quality.

An incorrect crossover setting is the leading cause of unhealthy competition between subwoofers and main speakers in the bass frequencies.

set sub phase and crossover make sub louder without amp

Due to the rivalry, they try to cancel each other, and that causes muddy and distortion of sound. By ensuring proper crossover settings, you prevent competition and receive better-quality sound without using an amplifier.

Just take your time and play some bass-heavy music while adjusting the phase switch until you hear the most powerful bass.

4. Use High-Quality Audio Files

Do not forget that your audio files’ quality has a direct impact on the quality of the sound that your subwoofers can emit.

Currently, many players in the music industry are trying hard to reduce their files through compression.

The compression causes the audio to lose some low and high-frequency information during the process and other crucial details that make the music exciting and loud enough.

flac vs aiff

Unlike with subwoofers, when you are listening to compressed music through headphones or earbuds, you may fail to notice the compromised quality. When you are choosing music files, remember that the higher the bit rate, the better the quality.

Keep in mind that lossless audio file formats are the best formats for sound quality. Examples of these formats include FLAC and AIFF.

Music streaming can also affect the quality of your music. Consider using apps that use a higher resolution. Besides, ensure the settings in your music app guarantee high sound quality.

5. Reduce Electrical Impedance

An efficient subwoofer should be able to convert electric energy into sound without many limitations.Reduce Electrical Impedance in subwoofer

Electrical impedance measures the degree of resistance that a subwoofer faces to execute this function. If your subwoofer has a high impedance, it has less ability to convert electric energy into audio.

The best way to ensure your subwoofer is in perfect shape and experiences minimal electrical impedance is to make sure its magnets and coils are fully operational.

The circuitry that controls your subwoofer should also be in perfect shape for you to realize this.

You will need the help of an electrician to check these components and replace any that may need replacing.

6. Add Sound Dampening Materials

One of the likely reasons your subwoofer is emitting low sound has to do with the vibrations from its enclosure.

Luckily, you can minimize the effect of the vibrations by adding insulating or dampening materials.Sound Dampening Materials to subwoofer acoustic foam

Many car users use this technique to make their car speakers louder. You can dampen the floor to help reduce the vibrations. This way, you can reduce the noise levels and increase sound accuracy with ease.

Creative made a very cute style statement with a cubical 7-inch enclosure. But experts will tell you, a cube is one of the worst designs due to parallel surfaces and Internal reflections. Also, The MDF was bare and glossy, giving a very boomy effect with peaks noticeable at 80~100 Hz.

We will be using a layer of acoustic foam. This foam absorbs reflections and cuts on standing waves. Giving a flatter bass response and reduced distortion. Due to space limitations, I could do only 2 sides. If your box is larger, try doing all sides. Hot glue works well for this purpose.

7. Replace the Cables

Like everything else, your entire home theater system needs proper cables to function properly.

The cable needs to be replaced from time to time. If the wires are old, they can adversely affect the electrical signaling, which often results in poor sound quality.replace subwoofer cables to make sub louder no amplifiers

Shop for quality made, adequately sized cables. They often tend to allow the free flow of current. The result is that your speakers will not get starved of the right amount of electric power they require to operate optimally.

Replace your cables now if they are worn and you have sound quality concerns but have used them for a long while.

8. Isolate Your Subwoofer From The Floor

Subwoofers produce a lot of vibrations. If you place your sub on the floor as many people do, much of these vibrations will reverberate through the floors, taking a lot of the sub’s output with it.

subwoofer isolation pad isolate subwoofer from floor

An easy way to fix this if you want to keep your subwoofer on the floor is to isolate your sub form the floor.

9. Add An Improved Heatsink

Heat is the enemy of electronics. In particular, subwoofer circuitry can generate a fair amount of heat which can significantly affect performance.

In particular, most subwoofers have built-in amplifiers which amplify the signal they receive. These small amps can generate tremendous heat.

Add An Improved Heatsink to subwoofer

One way to dissipate this heat faster is by beefing up the heatsinks. Where can you find an extra heatsink?

Well if you’re a DIY electronics hobbyist, they are easy to find in many electronics such as old amplifiers, computers, DVD players, power supplies, and more. You can also purchase a heatsink at your local department store.

If you find a heatsink larger than the one currently on your subwoofer circuit board or at the back of the sub, you can replace it with your larger heatsink.

All you would need to do is to apply a thin layer of heatsink compound on the contact surfaces and then you will probably need to glue down the heatsink sides because you may not be able to screw it down the same way you would the original heatsink.

How To Make A Sealed Subwoofer Louder

If your subwoofer is in a custom DIY subwoofer box, there are several steps that you can take to make the sub louder without an amplifier. Here are the steps:

1. Make A Custom Ported Subwoofer Box

As much as the type of subwoofer in the box is important, the enclosure has the most influence on how loud and deep your subwoofer will sound.

Connecting Multiple Speakers To An Amplifier

If you want to greatly improve your subwoofer’s performance by modifying the box in, a great way to do that is to create a custom ported box.

Instead of completely sealing the box, make it a ported design and this will greatly improve your sub’s performance.  For loud bass, you should tune the port in the upper bass region around 50HZ. You can also check out our subwoofer box design for deep bass.

2. Fill The Subwoofer Box with Polyfill

In general, you will find that sealed enclosures are smaller and more compact than their ported counterparts.

One of the easiest and best ways to improve the bass performance and achieve a deeper and richer bass sound in such an enclosure is to fill it with polyfill.

How does this work?

Fill The Subwoofer Box with Polyfill

Well, the idea is that the polyfill will slow the waves as they move through the box, making the box appear larger as far as the sound waves are concerned. This effect then helps with generating deeper bass extension.

Here’s how you go about it.

First, add a thick layer of polyfill at the bottom of the sub-box and add fewer thick layers as you move up.

Do not pack the box too tight or the bass waves will have an issue flowing through. When you reach the top, add cotton gauze. If you do not do that then the polyfill fibers will probably eject out from the port. You can also glue it down but be very careful to use simple paper glue and glue minimally.

Finally, ensure that you seal the subwoofer box tightly for an even better effect.

3. Choose A Box With A Sturdier Material

The material chosen for your subwoofer is very important. This is why many people choose to replace the enclosure that their sub is manufactured with.Subwoofer MDF Vented Port Sub Box Speaker Enclosure

One of the main considerations in doing this is ensuring that the material used to create the enclosure is very sturdy.

This improvement works well for ported enclosures but the effect is rather significant for sealed enclosures.

This is because sealed enclosures will often force sealed air to move around the subwoofer box causing the wood fibers to expand. This makes it rather inefficient over time. If you choose to make a sealed sub-box, then you can use a sturdy material like MDF or fiberglass.


Does A Subwoofer Need An Amp?

Begin by understanding the subwoofer subtype. If you own a premium-powered subwoofer, an extra external amplifier will not add value unless you want to move the output to extreme levels. However, if you have a passive subwoofer, it won’t work without an amp.

Why Do Subwoofers Need an Amp?

Suppose a subwoofer comes as part of a larger sound system. In that case, it’s easier to optimize it to work with the other setup components without showing any distortions due to inadequate power.

On the other hand, a standalone subwoofer may be too powerful for the sound system’s receiver or even the rest of the setup. Therefore, you may need an amp to help the sub to deliver deep and precise bass without sounding labored. Therefore need to have an external amp.

Final Thoughts

There is no denying that an amp can make your subwoofer louder. But if you do not want to use it for whatever reason or are on a tight budget, these tips can still help you achieve the desired volume. If you do decide to get an amplifier, please note that you need to think about what type of amplifier you need for your subwoofer

Besides, they will enhance your sound quality without interfering with your budget. In addition, check out our list of tips to make speakers louder without an amplifier. Please note that if you are experiencing low subwoofer volume problems, we have a guide on fixing subwoofer low volume issues.

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Norvan Martin is the founder of He is a professional Electronics Engineer and is passionate about home theater systems and AV electronics. BoomSpeaker was created as an online hub to share his knowledge and experiences as it relates to home theaters and home audio electronics. My email: [email protected]  Connect on Pinterest and Linkedin