How to Reduce Trunk Rattle From Subs – Quick Solutions

How to Reduce Trunk Rattle From Subs Cover Image

Don’t get amazed! Trunk rattle is the most common problem that I have dealt with. One of the reasons that can cause this unpleasant situation is the powerful bass from the subs. It not only shakes your trunk but the whole car can also be affected.

Stop worrying if you think you need to lower the bass to prevent the trunk lid from rattling. Many solutions can help reduce the vibrations. Why not give them a try before going to an expert?

However, you can use sound-deadening materials in the first place to prevent or at least your car trunk from rattling.

Let’s dive in!

Reasons Why Your Trunk Rattles Due to Subs

Before you take steps to stop these unnecessary sounds, you need to find the reasons behind them. You can check them below:

Poor Subs Installation:

Car trunks often rattle as a result of improperly installed subwoofers. When car speakers are not correctly mounted to the vehicle, they can vibrate and cause the trunk to shake or rattle.

Another issue that can cause a car trunk to rattle is when the subwoofer box or enclosure is not securely mounted. If the box is not tight and secure, it will vibrate excessively as the car audio bass kicks in.

Using Too Powerful Subwoofer:

Unfortunately, if you select too powerful a model or crank the volume too loud, you may find that the vibrations cause rattling in the trunk. This is because most cars’ trunks are not designed to handle the intense vibrating noise of a powerful subwoofer and can cause damage such as rattling, shaking, and even cracking.

Poorly Insulated Trunk:

Car Trunk Insulation

If the trunk is not insulated correctly, or if the insulation used is of inferior quality, then the vibrations from the subwoofers can travel through the car body and cause rattling in the trunk area.

The most common way that a subwoofer causes trunk rattling is when the car body vibrates due to powerful bass frequencies. If there’s insufficient insulation between the trunk and the cabin, these vibrations can cause rattling in the trunk area.

Loose Items Inside the Trunk:

loose items in car trunk that can make rattling noise

Another reason behind the noise is the moving items due to the heavy bass in the car trunk. This happens because sound waves cause vibrations amplified by loose items in it. The objects then vibrate and create noise perceived as a rattling sound. It is essential to secure any items in the trunk that could cause rattling, such as loose tools, boxes of things, or even a spare tire.

Amplifier Settings:

When setting up a car audio subwoofer in the trunk of your vehicle, incorrect amplifier settings can lead to rattling in the trunk. A bass boost or high pass filter is often the culprit, as it can cause the subwoofers to receive too much power and create excess movement, which causes rattling.

Faulty Subwoofers:

Sometimes, it’s not always the trunk that rattles. Using a subwoofer at higher bass volumes can cause the sub to lose performance throughout the time. As a result, you can start hearing the rattling or vibrating sound from the area.

9 Methods to Reduce Trunk Rattle From Subwoofers

Now that you know the cautions, let’s move forward to fix the car trunk rattling.

1. Install Sound Deadening Material:

Sound Deadening Material

You can use sound-deadening materials such as dynamat (1), fiber sheets, or self-adhesive sheets to contain and absorb vibrating sound in the trunk caused by subwoofers. These materials are usually made of thick foam or rubber that fits snugly within the vehicle’s trunk cavity.

It will break up sound waves, reducing their amplitude and thus preventing them from causing vibration and noise. Additionally, placed strategically around the subwoofer and other components, sound-deadening material can dampen vibrations caused by the bass.

Steps to Install Dynamat Inside the Trunk:

  1. Begin by preparing the trunk area for the installation of Dynamat. Ensure you clean the entire surface and remove any debris or dirt from the site, as this will ensure that your soundproofing material adheres better.
  2. Cut out several pieces of Dynamat in various shapes to fit snugly into all crevices and corners of the trunk area. Be sure to leave yourself a few inches of excess material around each piece you’ve cut out to allow for overlapping or trimming if necessary.
  3. Peel off the adhesive backing from each piece of Dynamat before applying it to the surface of your trunk. It is essential to press firmly on the Dynamat to ensure it is appropriately secured.
  4. Once all pieces of Dynamat are applied, you should trim any excess material around the edges to give your trunk liner a neater appearance.
  5. Finally, place the subwoofer into the trunk area and test your sound system to see if vibrations have been reduced or eliminated.

2. Ensure Subwoofer Is Tightly Secured:

If you have connected your subwoofer with a mounting bracket, ensure the frames you use are strong and durable enough to hold the subwoofer in place without any wobbling.

3. Use Correct Amplifier Settings:

First and foremost, selecting an amplifier that offers separate subwoofer output channels is essential. This will allow you to adjust the levels independently for each subwoofer so that they don’t interfere with one another.

Secondly, use a low pass filter on your amp to block frequencies above specific points. Your subwoofer is designed to play low-end frequencies, so ensure the filter is set up to allow only lower frequency ranges.

Thirdly, ensure that you use the correct size of subwoofer for your trunk space. If the size of your subs is too big or too powerful, it will cause excessive vibrations in the trunk.

4. Experiment with Different Positions:

Experimenting with different positions for subwoofers in your trunk can drastically reduce the rattling effect that occurs when playing music through them.

To start, make sure to adjust the gain or loudness setting on your amplifier to a moderate level; this will avoid any excess sound pressure being created and save your car speakers from possible damage. Next, you’ll want to begin experimenting with the position of your subwoofers.

5. Add Braces or Support:

Subwoofer supported by braces

If you are not using braces or support for your subwoofer inside the car trunk, consider installing them. Braces are typically metal frames with two bars connected by a series of struts and fasteners.

The purpose of these braces is to dampen the vibrating noise created by the subwoofer, helping to reduce rattling in the trunk. Moreover, braces can help secure the subwoofer, preventing it from shifting or moving around when driving.

When installing braces for your subwoofer, ensure they are correctly installed and secured firmly against the trunk walls. Additionally, use plenty of foam padding to prevent rattling and add stability. This will also help protect your car from any potential damage from vibrations.

6. Use Right-Sized Enclosure:

Subwoofer Enclosure

Using the right-sized enclosure can help prevent or reduce trunk lid rattling because of subwoofers by providing the perfect environment for the woofer. A properly sized subwoofer box can help reduce the amount of air movement created by the subs, which can cause vibration and rattling in the trunk.

It will also help to isolate the subwoofer from any sound produced by other components in the vehicle’s interior. Additionally, a sealed or ported enclosure will further help to reduce unwanted vibrations and ensure that your music sounds as clean as possible.

7. Ensure Other Items Are Secured Firmly:

Loosen Screws in Car Trunk

The key to preventing trunk rattling due to car subwoofers is appropriately securing the other items in the trunk. You can quickly do this using a cargo net, bungee cords, or even velcro straps.

These tools will help anchor down any loose items like spare tires or tools and prevent them from moving around as the car experiences vibrations from the bass.

Additionally, padding can also be used to reduce trunk rattling further. Placing items on a mat or in a box within the trunk will reduce the amount of vibration transferred from the subwoofer throughout the rest of the trunk.

8. Clean the Trunk Completely:

Cleaned Car Trunk

Regularly cleaning the trunk (or whole car audio) can help keep this noise at bay by removing any debris or objects contributing to it. This means vacuuming the entire area and wiping down surfaces with a damp cloth to remove dust, dirt, and grime.

9. Seal the Gaps or Openings in Trunk (Cheapest Way to Stop Trunk Rattle):

Gaps and Openings in Car Trunk

Sealing the gaps or other spaces in the trunk can help reduce vibrating sound caused by bass-heavy sounds from subwoofers. Filling the cracks with weatherstripping will prevent sound waves from passing through, resulting in improved sound quality and less rattling of the trunk lid.

By sealing any cracks, holes, or openings, you’re effectively creating a tighter box-like environment that doesn’t allow the sound to escape. This helps reduce rattling and improves bass response and overall sound quality.

Follow the below steps:

  1. First, you should identify the areas in your trunk that are prone to rattling. These are typically the trunk lid, side panels, or any other loose or vibrating parts.
  2. After identifying, make sure you clean the surfaces throughly where you will apply weatherstripping tape. Those spots must be free from dust, debris, or any other substances that could affect the adhesion.
  3. Now, cut the foam weatherstripping tape into small strips or pieces according to the size of the areas you want to cover.
  4. Remove the backing from the adhesive side of the foam tape and carefully apply it to the identified rattling areas. Press firmly to ensure good adhesion.
  5. Let’s repeat the process for all the areas that require damping to prevent rattling.

General FAQs

How Do I Stop My Trunk From Rattling With Subs?

One way to stop your trunk from rattling with subs is to add sound-dampening materials. Adding a thin layer of sound-dampening material in the areas where the subwoofers are mounted and in the trunk can help reduce resonant noise and prevent it from escaping outside your vehicle. You can also purchase pre-fitted acoustic foam or rubber mats to place in the trunk area.


What Causes Trunk Rattle?

Trunk rattle is a common problem that affects many types of vehicles. It is caused by items that vibrate inside the trunk, such as loose spare parts, improperly secured cargo, or items with sharp edges. The vibration produces an annoying sound that often increases in volume over time and can be heard inside and outside the car.


What to Do if Your Rearview Mirror Rattles From Bass?

If your rearview mirror rattles from the bass, properly attach it. Tighten any screws if needed and add foam padding around the edges for extra insulation. In addition, be sure to keep your car stereo at a level that won’t rattle the mirror too much.

External Sources

(1) Dynamat

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