How to Make Subs Louder Outside the Car?

Subwoofers are one of the most important components of any sound system. In the absence of a subwoofer, you will not enjoy the sounds created by the system, as there would not be enough bass for you to enjoy it. Hence, your subwoofer needs to be highly functional and loud when listening to music.

A few things might be wrong if the subwoofer in your car does not sound properly or loudly outside the vehicle. Hence, how can you make your subs louder outside your car? For a subwoofer to sound louder outside a car, it needs to have a good amplifier and as much power as it can get. Increasing the number of subs would also help to make it louder. Read on to see top recommendations on how to make subs louder outside the car.

Factors That Affect The Loudness Of A Car Audio System

There is a misconception that a speaker’s loudness depends only on its physical dimensions. Nevertheless, that belief is not true. While the speaker’s size contributes to its loudness, many other factors affect how loud the speaker can be.

Factors That Affect The Loudness Of A Car Audio System

Some car subs feature compact and small designs, but they produce loud, rich, and impressive sound quality. Here are factors that determine the loudness of car subwoofers outside the car.

Subwoofer Size

As earlier said, a subwoofer’s size plays a key role in how loud it is. However, this factor does not work alone, as it depends on other factors such as power handling, enclosure type, and sensitivity. The sub’s size is one of the major determinants of the audio system’s volume.

Bigger subwoofers move more air than smaller subwoofers, so they produce more bass. Nevertheless, irrespective of size, the subwoofer would be greatly limited if it did not have enough juice. Hence, a sub’s loudness depends on more than one factor simultaneously.

Power Handling

Power is another major factor that determines how loud a subwoofer can be. The amount of power a speaker and subwoofer can handle is measured in watts. All subs have a maximum wattage (determined by the manufacturers) they can handle. The number of watts a sub is designed to handle determines how loud it can be. Hence, the higher the sub’s wattage, the louder it can be.


A speaker’s sensitivity is measured in decibel (dB), and it works together with power-handling for higher output. A sub’s sensitivity determines how it converts electrical energy to sound energy. If a subwoofer has a high sensitivity rating, it requires less power to produce quality sound. Hence, a subwoofer needs a good sensitivity rating to produce a louder sound outside the car.

Enclosure Type

The type of enclosure used for the subwoofer also affects its sound quality and loudness. Sealed enclosures produce deep, better sound quality, but ported enclosures are louder. Some of the loudest subs feature ported enclosures for additional bass reflex. The downside of ported enclosures is that they do not provide the most accurate sound.

How to Make Your Subwoofers Sound Louder Outside the Car

A car sound system sounds better when the subs sound louder. Here are some tips for enjoying a loud subwoofer outside the car:

How to Make Your Subwoofers Sound Louder Outside the Car

1. Build or Buy Ported Boxes

One of the best ways to enjoy a massive bass boost outside your car is to put your sub in a ported box. If you are experiencing a low bass response, this simple trick can boost your sub’s bass quality. It would help you enjoy loud music and booming bass outside your car.

You can purchase a pre-made ported box or make one from scratch. A ported box reinforces low bass response by using a “Vent.” It redirects sound from the back of the subwoofer cone and blends it with the sound coming from the front, providing you with louder sounds.

A ported enclosure also gives the sub cones more freedom to move. However, not all subs are designed to be used in ported enclosures. Hence, ensure you can use your subwoofers in a ported box before building or buying one.

2. Opt for a Larger Subwoofer

As we pointed out earlier, a subwoofer’s size matters when it comes to loudness. Car subwoofers come in different sizes, ranging from 6 inches to 18 inches. The bigger a car subwoofer, the better its performance. Hence, if you want your subwoofer to sound louder outside the car, you should choose a big-size sub.

Before you opt for larger size subs, however, you want to ensure you have enough space for them. Nevertheless, that does not mean small-size subs are not powerful. In fact, a small-size subwoofer with better enclosure, power handling, and a great sensitivity rating will produce loud bass waves to enable you to enjoy quality music.

3. Good Sub Positioning

The positioning of your car subwoofers also matters a lot. Never underestimate a good sub position, as it can enhance the bass quality significantly. The right sub position can boost its volume enormously.

If you want the sub to sound very well outside the car, we recommend you position it at the back of the trunk. That would help to amplify the volume and bass effects of the subwoofer. If the subs are facing the car seat, turn them to face the car trunk and not the seats. In addition to producing loud sounds outside the car, this position will make the sub sound loud inside the car.

4. Increase the Number of Subs

Another productive way of increasing the bass quality and loudness of a sub outside the car is to increase the number of subs. Two subwoofers are better than one, provided they have the same brand and model.

If your car sound system is powerful enough to run multiple subs, do it. Multiple subwoofers punch harder and play louder because more cones are involved, providing a smoother and much better bass response. Nevertheless, properly set up the multiple subs to avoid an irritating or poor-quality sound.

5. Provide Sufficient Power

Power is one of the major determinants of a speaker’s loudness. Without sufficient power, you will not enjoy better and loud bass, regardless of the sub’s quality. Bass notes consume a lot of power, so you need to feed them properly to ensure premium bass quality. However, you want to ensure that you are not overworking the amp in use, as it could send a clipped signal to the subs.

Clipped signals are not friendly to subwoofers, as they can overheat and burn out the subs. It is worth noting that many car subs can handle a little more power than their recommended RMS ratings. Hence, it is safe to feed them a little more power than their recommended rating, provided the power is distortion-free and clean.

6. Open Your Car Windows

Do you know that opening the sunroof and windows of your car can enhance the loudness of your subwoofers outside the car? Opening the windows will allow air to roll into the car, causing more sound waves to travel outside from the car. The air entering from the windows and sunroof will continue pushing out more sound waves from the car.

Air is the medium through which sound travels from one place to another. Hence, by allowing greater airflow, greater sound waves will travel more distance.

7. Fine Tune Your Amplifier for Loudness

Using a powerful amp and increasing the number of subs you use can make the subwoofers in your car sound louder outside the car. However, installing these components alone will not do the trick sometimes. To enjoy super loud and clean bass, you have to turn the amp’s settings.

You might experience muddy bass sounds or distortion if you do not adjust the settings in the amp. In some cases, having a muddy bass sound or distortion is more terrible than not having any subwoofer. Hence, you want to avoid such an event as much as possible.

Amps have many filters for fine-tuning the effect of your sound. Two of the most important filters are the high pass filter (HPF) and low pass filter (LPF). Here are some tips for adjusting your amp settings to get the most out of your car subwoofers outdoors:

  • Turn down your sub amplifier gain
  • Turn off the bass booster
  • Increase the low-pass filter
  • Put on the head unit and set all the equalizer configurations to zero
  • Keep the volume of your music below 70 percent.
  • Increase the volume on the amp until you see the clipping light or hear the clipping sound.
  • Once you hear any distortion sound, reduce the gain until it goes away. Most times, the reduction goes away when you reduce it by about -6 dB.
  • Reduce the low-pass filter until you no longer hear any mid frequencies but only bass. Sometimes, you might need to reduce it by almost 50 percent.

You can tune your subwoofer amp with the above process to provide a better and louder sound outside your car. However, if you do not know how to turn your amplifier, you can outsource the process to a professional.

Final Thoughts

Good car stereo systems can turn more heads while driving through the streets. Many people use their car’s sound or stereo system to enjoy great sound in little outdoor gatherings. Many factors contribute to a car stereo system’s loudness, including its power handling capability, proper tuning, and more.

There are many ways to make your subwoofers louder and provide the best sound quality outside. With huge voice coils, enough power, the right subwoofer box, and a well-tuned subwoofer, you can enjoy a deep bass depth and enhanced audio effects outside your car. With the tips in this guide, you can make your car subwoofer louder and enjoy a very loud sound.