Have you ever heard a car driving down the street rattling so bad that it sounded like it could fall apart right in front of you? A lot of the time this is due to not using a soundproofing solution when they did their car audio installation. To put a stop to this once and for all, I present to you the best sound deadening sprays and paints that I have come across.

The top pick is by one of the best in the business, and that’s Design Engineering who is responsible for manufacturing the Boom Mat (spray edition). It helps keep your temperature-controlled and is specifically designed for powerful systems. Not to mention, they have made one of the best products in the business without making it a lot more expensive than competing products.

Care to learn more? I’ve got you covered, just keep reading!

Sound Deadening Sprays & Paints We Recommend

Our Pick

Boom Mat Spray-on by Design Engineering

One of the best things about this deadening spray by the folks at Design Engineering is that it acts as a thermal barrier as well. What this means is that you can use it to make the space that you’re spraying with it resistant from excessive heat.

In turn, this will also protect your car audio equipment from overheating as well, unlike cheaper options that might not come with this benefit.

Each can will cover an area of up to 20 square feet, and it can be coated with paint in as little as six hours. The best part of all is that it’s crack and chip resistant. A lot of sound deadening sprays will chip or crack upon impact, but not this Boom Mat spray.

The price is right in the range of all of the other sprays on the market, which makes sure you don’t have to pay a lot more to get your hands on one of the best products of its kind.


Professional Grade Rubberized Undercoating by 3M

The runner-up comes from a familiar name in the world of special coatings, and that’s none other than 3M itself. It’s designed to be an undercoating for vehicles, but many people have also found success when using it to deaden the sound of subwoofers and other pieces of car audio equipment.

It is an asphalt-based product which means that it can be more durable when used on the underbody of a vehicle as well as be resistant to rust and corrosion. Keep in mind that if you’re applying it to an area with rust, the rust will need to be treated first or the results won’t be close to acceptable.

Many have found that this can doesn’t go as far as our top pick, and that’s the major downfall to this sound deadening product. However, it’s still proven itself to deliver where needed even if it might take a little bit more of the product than some of the other brands out there today.

On The Budget

Rust-Oleum Professional Grade Rubberized Undercoating Spray

This is another big name in the industry, but you’ll find that this is more of an affordable approach than anything. It also has a lot less coverage than all the other products that I reviewed, making it a more expensive option in the long run if you have a lot of areas to cover.

It does come with an “any angle” spray tip which makes it easier to apply in those hard to reach places, as you can even spray the can if it’s upside down. While it says it dries in under an hour, many customers said it takes a lot longer for it to setup.

If you want to be budget-conscious and still deaden the sound or embrace an underbody coating, this is the best option. However, if you want the best performance and longest lifespan, you better bill willing to shed out a few more buck to get your hands on some of the higher-rated products of its kind.

Also Great

U-POL Raptor Black Urethane Spray-On

Now we start entering the arena of true audiophiles who demand zero unnecessary sounds caused by a non-insulated vehicle. Keep in mind that when you go this route (or even with the LizardSkin option that I’m reviewing next), you will be paying a premium price since it’s considered a premium product.

The main reason that this didn’t make it to the top of the list is that the price is a little more than you would pay for a spray can, but the results are a lot better in most cases where you also need a bed liner or where the application is covering a large area.

For just a little over a hundred bucks, you get the ingredients you need as well as a bed liner spray gun with a built-in regulator. This is an all-in-one package that’s sure to tack your soundproofing project to a whole other level. While it’s a bed liner, it’s highly effective when it comes to its sound deadening capabilities which is why it’s one of the longer-used brands in the world of car audio.

Also Great

LizardSkin LSCI-4GAL Kit Ceramic Insulation with Spray Gun

With this kit, you can cover up to 100 square feet and you’ll be provided with everything you need to get things done efficiently and effectively. The ceramic particles that it uses create one of the best thermal barriers that I have personally seen over the years, especially when soundproofing to get the best sound out of your system.

It is the most expensive on the market, so you must prepare yourself to be set back a few hundred bucks if you go with this route. It does come with the spray gun and mixer, so you won’t have to run out and buy any extra tools (unless there’s not a drill in your tool collection).

As for the results that it has produced for customers, it’s one of the highest-rated sound deadening spray applications, but the others in this list were able to outrank it with a better price tag.


A lot of the time I get the same questions over and over from readers about how to deaden sounds in a car. I took these questions and answered them for you below to save you as much time as I can.

What is deadening spray?

Think of deadening spray as insulation for your vehicle that prevents unwanted noises from arising due to the use of a powerful car audio system. Some come in the form of a foam, special coating, or a specialty paint that you can spray on.

A sound dampening spray provides the needed surface that will effectively absorb the soundwaves to keep things inside and outside of the vehicle sound as clean as they possibly can. It’s what separates a professional-quality install apart from the rest, to say the least.

Why would I use one?

If you don’t want to have to deal with the headache of a sound dampening mat, this is the alternative that’s the easiest. Instead of having to cut the mat to fit the areas you need it installed or risking not being able to cover certain areas, you can spray the car in its entirety within just a few hours. Or in less than an hour if you’re only soundproofing a certain area of your car.

Many sound systems don’t sound as good as they could if they would’ve taken the time to spray some in their vehicle. The cars you hear rattling so hard that it sounds like they’re about to fall apart driving down the streets are a great example of this. Be the one that sounds like a true audiophile, not an amateur.

How does sound deadening spray work?

Subwoofers (and other types of speakers) create soundwaves. When these sound waves travel, they create a vibration that’s absorbed by the objects that are within the environment. To prevent these unwanted noises from surfacing, the deadening spray can absorb it instead once it’s dry.

There have been previous studies done that have proven sound deadening sprays to be capable of eliminating unnecessary noises in their entirety. Making it a great application for those who are adding the bass they crave to their car audio system.

Spray vs Mats

You’ve got a lot of surface area to cover, you’ll find that it’s easier and more efficient to use sound deadening mats which are thicker right out the gate (just to achieve this thickness you’d have to spray on several coats of sound deadening spray). However, there are places that might not be able to be soundproofed with mats, and this is where you’ll find the spray to carry its weight in gold.


Absolutely, it’s easier to apply where there’s not much room to work with and a lot quicker than using sound deadening mats. It also eliminates one of the most common drawbacks that a mat can come with which is not fully deadening the sound and stop rattles when playing your system.

It can fully eliminate the vibrations which are why it has been a favorite among professional car audio installers. If you want the ultimate soundproofing solution and still want to use a mat, just spray this on before installing the mat itself.

What’re the disadvantages?

While using deadening sprays can seem like the best option for most, just like anything else it does come with a list of cons too. Below are the most common ones that have been noticed the most.

  • A common issue is a limited lifespan, but this is usually only with cheaper sprays.
  • Cheaper sprays have been known to have unpleasant odors.
  • Heavy impacts could cause the sound deadening spray to chip.
  • Multiple layers may be required in some applications.
  • You must mask areas before application to prevent overspray.
Vincent Talbot

Last update on 2020-10-17 / Affiliate links / Images from Amazon Product Advertising API