Soundproofing Your Car: How to Deal With Unwanted Noise

Whether you’re driving an old car, want to make your morning and evening commute more peaceful, or are passionate about how your car sounds, there are many reasons why you may want to make your car quieter. Soundproofing a car is not something many people are aware is possible. Most cars, older ones especially, create a lot of noise. The problem can become even worse if you’ve upgraded your car or sound system in any way. And contrary to popular belief, keeping your car running quietly isn’t only a matter of blocking outside noise, but reducing the noise created by your vehicle as well. Loose parts, vibrations and rattling are all things that contribute to that loud and unwanted noise.

Common Causes of Unwanted Noise

Before buying a sound deadener for car, you should first identify the noise and the type of materials needed to tackle the problem. The two most common causes of unwanted noise are airborne and structural noise. Airborne noise refers to the noise from sirens, honking, construction and other sounds from the urban environment making their way into your car. All of these sounds happen when you aren’t driving, so when you add the noise that comes from driving on uneven pavement, debris and potholes, it’s a concoction that can make you go insane. All of these sound waves go through the air and penetrate your car making their way inside.

Structural noise refers to the vibrations and noise coming from the parts that make up your car. The engine, tyres, exhaust system, metal panels, etc. all create a fair amount of noise in the form of rattling, reverberating or shaking. So you should pay attention to what’s causing the most noise in your car. Perform some detective work to see where the noise is coming from to determine the problematic areas and the type of car sound deadening you need.

Types of Car Sound Insulation Materials


Now that you have an idea of what the different types of noises are, and where they can come from, it’s time to consider the different types of sound deadener for car materials. There’s not a single material that can fix all your issues, as different products are designed to resolve different issues. For optimal noise quality inside your car, you should use a few different materials in combination with one another.

Sound deadening materials, also known as vibration dampening materials are the most basic noise reduction product for vehicles. The most basic principle of sound dampening is to adhere to a material that will resist the vibrations made by metal surfaces which resonate sound. The soft, sound deadening material will reduce vibration energy and dissipate it as heat, reducing the vibrations significantly. These materials are typically applied inside your car – on the firewall, under the carpet, on the roof, inside the door panels and trunk, etc. Some of these materials can also act as thermal insulators.

Then, there are sound blocking materials. In order to get a clear understanding of how they work – think a soundproof room. The sound blocking materials are placed on the walls and the door of the room is completely sealed to prevent unwanted noise from finding its way inside or out. For cars, you can’t shut out everything because the windows will always be prone to sound, but you can still apply these materials to a few key areas and block a large portion of unwanted noise. These materials are typically used to block road noise, engine noise and exhaust noise.

Lastly, you’ll find sound-absorbing materials that are usually foam products designed to absorb or trap airborne noise. There are two types of foam materials – open and closed cell. Open-cell foam products absorb mid/high-frequency sound waves, whereas closed-cell foam products absorb low-frequency sound waves. Both open and closed cells can provide a decent amount of thermal insulation as well.

How to Soundproof Your Car?

Soundproofing your car is relatively easy. Firstly, drive around and identify the source of the noise. Is it airborne noise coming from the outside? Or is it from vibrations or rattling from your own car? Identifying where the noise is coming from is key to determining the type of soundproofing material you’ll need. Next, strip the area of parts, wires, carpets and everything else that’s in the way, until you get to the metal. If the metal is removable, remove it so you have an easier time applying the soundproofing material. Once you’ve reached the metal, clean it with denatured alcohol. Even though most soundproofing materials are sticky on their own, applying denatured alcohol will improve bond strength. Lastly, apply the soundproofing material to the sheet metal, and leave it out in the sun to ensure it’s pliable. Make sure the material is applied properly, otherwise it may lose some of its effectiveness.