How to Reduce Noise and Make a Car Quiet Inside?


We spend a large portion of our lives in cars, and most of us with it was less noise coming from outside to the cabin, but how to make a car quiet inside? I did some research about sound deadening the car, and I want to share it with you.

To make the car quiet, we should consider soundproofing its interior to reduce the noise level inside the cabin. In practice, that means we should install layers of sound-deadening materials in the car’s critical parts like doors, floor, roof, and trunk area.

As an Amazon Associate, ImproveCarAudio will receive a small commission from qualifying purchases made through the links in this article.

Unless you own, for example, Rolls-Royce Phantom VIII, sooner or later, you will come across the problem of extended noise inside a car. Unlike in the past, today’s cars are made without proper soundproofing materials due to cost savings or weight reduction.

The article below shows the importance of soundproofing a car and how to do it. Let’s go through more details so you can start listening to music and not to all noises coming from the outside.

What affects the noise level inside the car?

The noise level inside of the cars is mainly affected by the size of the car and its shape. Noteworthy is also the class of the vehicle. The higher and more luxurious, the better and more soundproofing materials are used, and as a result, driving is more comfortable.

how to soundproof the car

Car producers are competing with each other and developing more advanced solutions to make sure their cars are quieter than the other brands. They often use additional soundproofing materials, laminated windows, or even curved shape of the wall between the engine and the cabin to reduce sounds coming from the front of the car.

All of these changes help to reduce the noise level, but it is still quite load inside of the majority of cars. There are several areas from which we hear noises louder than expected:

  • The most significant portion noises we hear that hitting us from the engine and gearbox. That can be especially annoying when we drive with modified, or worse with damaged muffler and exhaust.
  • Wheels are another source of loud noise in the car. Although many vehicles have soundproofed their wheel arches, the rolling tires on the tarmac cause unpleasant sounds. In the case of the wheels, sound deadening is not the only solution. Very important is also choosing the right tires.

The noise level increases not only with the width of the tires but also with their type. For example, winter or all-season tires (especially M+S) are much louder than summer ones because of the different rubber characteristics. Winter tires are softer and more sticky to the ground, so if you use them in the summer, be prepared for a lot of noise. The same applies to off-road tires when used on tarmac.

  • You can’t forget about the noise caused by the air passing through the car body panels and door seals, creaking interior, air conditioning, and vibrating doors that create noise like resonance boxes.
  • The size and position of the door mirrors are also affecting the level of the high-frequency wind sounds coming to the cabin. Unfortunately, in most cars, we cannot change it unless we replace them with smaller ones.

Types of sound deadening materials for cars

When searching for the right deadening material for your car, you will come across two isolation types:

  • The materials that prevent noise from coming into the passenger area.
  • The materials that absorb and soften the sounds created inside of the cabin, for example, acoustic foams.

The majority of the deadening panels used in the automotive industry, act like sound blocking and absorbing materials at the same time. More importantly, though, they can reduce vibrations and rattling of car’s metal body panels.

There are a few main groups of the soundproofing materials available, and each of them has a different characteristic that should be applied in the specific areas in the car:

  • Sound deadening car mats are the most popular and used to cover large areas of metal panels. The best quality have the butyl mats due to their flexibility and ability to keep material consistency in extreme temperatures.
  • Foam insulation and woven fiber are the thickest from all options. They are best to cover floor and trunk areas underneath the carpets, and great for plastic door panels. In addition to reducing noise, they are great heat isolators.
  • Sound dampening rubber sprays and foams are suitable for the inaccessible car areas where due to the shape, applying standard mats is impossible, like door tight corners or roof metal profiles.

What to look for when buying car soundproofing materials?

Most stores and workshops use specific, branded products they use and trust. But when choosing deadening materials yourself, pay attention to product quality. It must be flexible enough not to break in the winter, but at the same time do not fall off from the metal during the hottest months in the summer.

Low-quality deadening materials often have to be replaced because they have changed to the tar and contaminated the car’s interior. That is especially dangerous for the roof panels in dark cars, where the temperature is the highest.

Another thing to pay attention to is the quality of the adhesive side of the panels, that sticks to the metal areas. Some products can be easily attached to even slightly dusty surfaces, but in the case of mediocre quality deadening mats, you may need to entirely clean body panels before gluing.

Can I DIY sound deaden car?

Sound deadening car improves overall music experience, making the sounds clear and stronger. The most significant improvement after soundproofing the vehicle we notice is mid-bass coming from the door’s speakers. That is why we should focus primarily on the doors when improving the car audio system.

Most often, we leave sound deadening for the professionals. The good thing is, however, there are ways to deal with unwanted sounds in the car, and you can do it yourself. There are no special tools needed to remove door panels or seats and carpets from the car.

To start soundproofing your car, all you have to do is to make some online purchases to buy quality deadening materials, a free weekend, and a bit of motivation to play with your vehicle. For example, I am the guy that spends every weekend doing any kind of car work, and for me, it is the best time to relax.

If you are wondering where to put sound deadening in the car, there are key areas to focus on, if you want to notice real silence in the car afterward.

soundproofing car floor

Sound deadening car doors.

With sound deaden doors, thanks to removed vibrations between plastic and metal elements, we can start hearing actual quality music played by speakers, rather than rattling plastic door panels.

Correctly isolated doors work like speakers’ enclosures and make sounds more dynamic. It is like having a speaker playing in the free air; versus another one mounted into the box, the difference is huge.

Although doors in your car can be deadened with typical bitumen sound deadening mats, this is not the best choice. Bitumen can break when it is cold, and keep it glued to the other than flat surfaces can sometimes be challenging.

The best choice for doors will be butyl rubber panels. They are flexible and can be easily adapted to needed shape without the risk of any damage.

Process of deadening the doors is not complicated, and there are few simple steps to follow:

  • Remove interior door panels and speakers.
  • Remove the foam, paper shield, and any other elements that cover the raw metal door.
  • Clean the door interior and degrease metal surfaces with rubbing alcohol.
  • The soundproofing mat should fill the inside of the door on the outer sheet metal, also behind the speaker. Do not leave any air bubbles between rubber and metal.
  • Use thick foam rubber, for example, Luxury Liner Pro, on the plastic door panel. This way, you will eliminate the crackling sounds and vibrations from the plastic and will make the door sealed like a proper speaker enclosure.

Soundproofing the car roof

To soundproof the roof, first, we have to remove the headliner and thoroughly clean the surface underneath. Roof areas have to be measured accurately to cut the exact sizes of the sound deadening panels.

The best for the roof will be butyl mats that will not melt from the high temperatures. To make sure there are no air bubbles behind the mat, use a plastic or wooden roller. As a second layer, it may be worth adding a noise-absorbing rubber foam.

sound deadening car roof

Sound deadening the car floor

Making car quiet cannot be completed without sound deadening the car floor. You have to remove all seats, carpets and to clean thoroughly and degrease the entire car floor.

The first noise deadening surface will be the butyl mat, which will also protect against vibration. The second layer, which many people skip, will, in addition to noise reduction, create thermal insulation. The best for it will be self-adhesive rubber foam.

Soundproofing the trunk area

Soundproofing the trunk is often a great occasion to cleaning this area. Before starting work, everything from the trunk has to be removed, including carpet, spare wheel, and everything else you keep inside.

When empty, remove all interior panels and vacuum all metal surfaces thoroughly. When clean, use a wet cloth to wipe all areas and remove oil places. Do not leave oily spots, because this can prevent glued surfaces from the right connection.

Like in other areas of the car, before starting to glue deadening materials, you have to cut all pieces to the right size. When sticking mats to the metal elements, make sure there is no air between the surfaces.

After covering the entire trunk with mats, the next is the use of soundproofing spray and apply in the all small hard to reach areas and tight spots.

Soundproofing the engine area in the car

Sound deadening the engine also has a significant impact on driving comfort. Materials used, however, have to be placed only on the inner side of the hood. Even if matt will not touch the engine, it has to be heat resistant due to the high temperatures inside of the engine area.

Before installing the soundproofing mats, open the hood and clean it entirely. Not only wipe it from the dust but also remove all kinds of dried oils and liquids.

When your hood is ready, measure the mats, cut them to the right size, and stick all carefully to the prepared surface. Pay attention to the side of the mat that will be closest to the muffler, this is the hottest part of the engine, so it is crucial to ensure it will not fall off.

Important

Thanks to soundproofing mats, the engine area will reach the optimum temperature faster, which improves the engine work quality in the winter.

Martin

Welcome to ImproveCarAudio! I am Martin, and I love to write about everything related to car sound systems. I strive to provide the most accurate and helpful information about car audio through extensive research, as well as my experience with car audio installations.

Related Articles