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How to Reduce Trunk Rattle From Subs?

There’s nothing like the bass thump from a good subwoofer system to get your heart racing. But if you’re not careful, that killer bass can also lead to trunk rattle, which can be both annoying and dangerous.

The level of subs rattling depends on the subwoofer and the rest of the system, but is there any way to reduce trunk rattle from trunk? Let’s find out.

To reduce or eliminate trunk rattle from subs, you’ll need to sound deaden all metal panels on the floor, walls and the lid. Also, use foam distance pads underneath the subwoofer box to reduce vibrations that can cause rattles. Finally, set the correct gain and the optimal frequencies on the LPF filter.

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Tip: When sorting the subwoofer out, do not forget to remove any unnecessary tools or anything not required that can create unwanted rattling or noise from the trunk. 

If you still need to carry some tools, place them in the dampened trunk organizer (link to Amazon) rather than directly on the floor. This way, they will not rattle, creating annoying sound effects. 

In this article, I will show you some tips on reducing trunk rattling from subs, so you can enjoy your music without worrying about ruining your sound experience.

How to Make Trunk Stop Rattling From Subs?

There are a few ways to reduce trunk rattle, but the most effective way is to use sound-deadening material. This will help absorb the subwoofer’s vibrations and prevent them from causing the trunk to rattle.

Second Skin Damplifier Pro Premium Car Sound Deadening Material (2mm) – Butyl Rubber Auto Sound Deadener Mat (13.67 Sq Ft, 8 Sheets) – Made in The USA

There are a few different types of sound deadening material that you can use, but I recommend using thick foam from Second Skin or Dynamat (links to Amazon).

Both of these high-quality materials will significantly reduce trunk rattle, but I prefer Second Skin because of its higher flexibility.

Another way to reduce trunk rattle is to ensure that your subwoofer is correctly mounted with a cushioned mat underneath. As a standard, mats are not used, but instead the subwoofers are placed directly on a thin carpet which cannot effectively dampen the vibrations.

You can use ready-made sound mats (link to amazon) or any foam-based mat (even the exercise mat) and cut it to the correct size.

In addition, you may need to reduce the amplifier’s gain or adjust the LPF (Low Pass Filter) to a higher frequency.

By doing this, you will reduce the amount of bass produced by the subwoofer, or make it slightly softer, which will minimize trunk rattle.

The above steps can reduce rattling in the trunk but will not eliminate vibrations completely.

Do All Subwoofers Rattle?

All subwoofers will cause some degree of trunk rattle because of how the low soundwaves are created. However, the more powerful subwoofer you have, it will generate higher SPL (Sound Pressure Level) and in effect, cause more trunk rattle.

If you’re looking for a subwoofer that won’t rattle your trunk, you may do better with the thin under-seat subwoofer than with a standard enclosure.

KICKER 46HS10 Compact Powered 10-inch Subwoofer

Underseat subs will not make the whole car shake but will add the missing lowest tones. My favourite under-seat sub (or behind the seat) is the Kicker 46HS10 with its shallow 10″ driver (link to Amazon).

Can I Stop Vibration From Subwoofer in Car?

If you want to get rid of vibrations completely, you may need to change the music volume, reduce the amount of bass, or remove the subwoofer from the car.

But is this the right solution if you truly want to enjoy your favourite tunes? I am not sure about it.

From my experience, I can say that it is possible to significantly reduce vibrations by using sound-deadening material and making sure that the subwoofer is properly mounted.

However, it is not possible to completely eliminate all vibrations from a subwoofer without turning it off.

Is It Worth to Sound Dampen Trunk?

Sound dampening the trunk is worth it if you want to reduce trunk rattle and enjoy your music without worrying about damaging your car or hearing any annoying sounds coming from the back of the vehicle.

Not only will sound deadening material help to reduce trunk rattle, but it will also help to improve the overall sound quality of your car’s audio system.

After sound-dampening the trunk, you will feel like sitting inside the acoustic studio without hearing any road noises or other external sounds.

So if you’re looking for a way to get the best possible sound quality from your car audio system, I would highly recommend sound dampening the complete trunk, or at least the metal areas and all the interior panels.

How to Sound Deaden Trunk?

Sound deadening the trunk is not difficult, and you should do it in any car audio system if you want to improve the overall sound quality.

The most effective way to sound deaden the trunk is by placing rubber panels on all metal panels. These materials effectively absorb vibrations and prevent rattling the car’s interior.

In addition, I recommend using a foam spray in all tight areas where mats do not cover the whole surface.

Remember that you sound deaden the trunk to seal it like a large enclosure, so any not covered areas will make the soundwaves hit the metal parts.

Below I show you a step by step guide on how to sound deaden the trunk of your car:

#1. Remove All the Materials From the Trunk and the Whole Interior.

Start by removing all the materials from the trunk, such as the spare tire, tools, and any other objects you may have in there.

Having a clean working area is crucial so that you can easily access all the surfaces that need to be sound deadened.

#2. Clean All Metal Surfaces in the Trunk

Use a degreaser to clean all the metal surfaces in the trunk. This will ensure that the mats will stick properly and last a long time.

Clean entirely the metal panels focusing mainly on all oily or greasy areas.

#3. Measure and Cut the Sound Deadening Mats

After cleaning the trunk, it is time to measure and cut the mats.

These materials are available in different sizes, so you will need to measure the areas where you want to apply them and cut the mats accordingly.

It is important to use gloves when cutting these mats because they are sticky, and you don’t want to get them all over your hands.

#4. Place the Dynamat Mats on All Metal Surfaces

Now it is time to apply the mats to all the metal surfaces in the trunk.

Make sure to press them firmly using a roller to adhere to all connections correctly and last a long time.

Car Sound Deadening Roller Metal Installation Tool 3 Pcs for Auto Noise Roller Car Sound Deadener Application Installation Tool Rolling Wheel Interior Accessories

You can also use a heat gun to soften the mats before applying them.

This will make them more elastic and sticky, preventing them from coming off over time but do not put too much temperature. Otherwise, the matt can melt.

#5. Apply Foam Spray in All Tight Spots.

After applying the mats on all metal surfaces, it is time to use a foam spray in all the tight spots where the mats cannot cover entirely.

This will help fill all the gaps between the panels and prevent soundwaves from hitting car bodywork.

Make sure to use a good quality foam spray to last a long time and not damage the materials in the trunk. I recommend Boom Mat, which creates a thick elastic surface.

How Much Does It Cost to Sound Deaden Trunk?

For the complete trunk sound deadening, be prepared to spend around $200 – $400. The price will depend on the quality of the materials that you use and the size of the trunk.

If you want to save money, you can sound deaden only the main surfaces in the trunk and lid and not use any foam spray.

This will still make a difference in the overall sound quality and reduce the external road noises but will not create the sealed environment that would be ideal for subwoofers.

How Do I Make My License Plate Not Rattle With Subs?

This is a small detail I am sure you have seen many times in cars with upgraded subwoofers.

Everything seems fine until you stay behind the car and hear the licence plate shaking and vibrating like it was trying to escape from the vibrations.

This is because the places are screwed to the back of the car through thin plastic shims that do not reduce any vibrations and actually make things worse.

The simple fix is to unscrew the plate, add some thin Dynamat stripes to the back of the plate and screw everything back together.

This will make your licence plate not rattle with subs and prevent the sharp plate’s corners from scratching the paint on your car.

Conclusion

Reducing trunk rattle from subs is not difficult, but it requires time and patience. However, following the steps above will allow you to sound deaden the trunk and make it rattle-free.

The most important thing is to use suitable quality materials so that you don’t have to do the job again in a few months. I hope this article was helpful, and if you have any questions, drop me a message.