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BY Hank O'Hop / LAST UPDATED ON October 15, 2021

You're driving your project car along and everything's going well. That is until the tires begin chucking gravel into the wheel well and blasts ring through the cabin like mini explosions. Yep, you forgot to install the sound deadening. Sound deadening is important, and it's one simple mod that can make your car infinitely more livable for you and the passengers. Even if a car has sound deadening from the factory, adding a few extra layers in key places to your older ride can make an economy box feel a whole lot more like a luxury cruiser. Everyone has room for sound deadener in their life, so we want to talk about some of our favorite options and how you can hunt some down for yourself.

Dynamat leads the industry for a reason. The quality and performance of the 36 square feet of 50-mil deadener in this kit will make you a believer.

80 mils and 36 square feet of surprise exist in this kit. Despite the low price, Kilmat delivers, and the product takes the beating you'd never expect it to.

Sometimes, you just need more. This kit is enough to cover 312 square feet with 50 mil sound deadener. The looks, performance, and quality are sure to impress. 

Our reviews are driven by a combination of hands-on testing, expert input, “wisdom of the crowd” assessments from actual buyers, and our own expertise. We always aim to offer genuine, accurate guides to help you find the best picks.

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The track record of performance and quality makes it hard to go with anything else. 

When it comes to sound-deadening insulation, it's hard to ignore Dynamat as the brand is responsible for birthing this segment, and the fact that it's still leading the industry says a lot about the quality of the product. Though it's easy to apply, it's not flimsy, easy to tear, nor will it crumble in the face of harsh conditions. On top of that, it's incredibly tacky and won't simply peel away after a minor bump. The use of Dynamat will reduce sound by 5 decibels, which might not seem like much, but it can lower the intensity to an impressive degree. 

It also offers respectable resistance to heat, up to 225 degrees Fahrenheit, which makes it safe for use on virtually the entire cabin of your car. We already know that the price is going to be an issue for many as this product does cost nearly triple the competition. It's also relatively thin, and there is speculation that it doesn't perform quite as well as some of the more affordable options because of it. 

While many will argue that it's worth spending the money on top-tier names because this is the kind of job that you don't want to do twice, there are some affordable products that flat-out deliver. Kilmat is one of the most affordable names on the market, and that shows as this entry is a third of the cost of premium offerings. Despite that, it's able to cut down noise dramatically thanks to the 80 mil thickness. 

Furthermore, it adheres very well to bare metal with proper installation and won't peel away, even in some of the worst conditions. We'll also tip our hat to its ability to resist heat just shy of what the high-end stuff can withstand. As with anything affordable, there's always a compromise. In this case, it's installation. While it's not much harder than others, getting it to adhere often requires a heat gun. Also, the material produces a strong odor and can be difficult to cut to shape. 

So far, our options have only covered 36 square feet and that's enough to get the floor and firewall in compact cars. What if you're not working with an econobox? What if your work van needs coverage from top to bottom? You're in luck, as this option from Siless covers 312 square feet. Though it's only 50 mil thick, it still does a good job of cutting vibrations to size and quieting down the cabin. Perhaps one of the best details about this pack is that the aluminum foil layer is black, making for a low-profile, almost OE feel to the product. 

Oh, and it's probably worth mentioning that it's exceptionally easy to work with as, even though it comes with a roller, it’s easy enough to work with that you won’t need it. As for issues, there's very little to report here. The obvious drawback will be the price and how much sound deadener is included. It's more than most are willing to pay and more than what most need. We should also make mention of the fact that the bulk sets can include logos stamped on some sheets and not on others, which is something to be aware of during placement.  

It’s a useful tool for getting into hard to reach places or those where traditional deadener can’t be used. 

It's time we turn our attention to an alternative type of sound deadener. Unlike all of the other products on our list, this doesn't come in sheets that adhere to the surface, instead, you spray DEI’s Boom MAT on. That's a major deal for when you need a deadener in hard-to-reach areas or filling gaps that sheets simply cannot. The product dries to the touch in just 20 minutes, and you can apply a layer of paint over the top in six hours. This stuff is also rather tough and can be used on exterior parts of the vehicle. 

Applying a layer of sound deadener to the inside of your car's wheel wells or floor pans is made extremely simple with this spray. Also, one can is enough to cover roughly 20 square feet, and since this includes two cans at half the cost of already affordable options, the value is impossible to ignore. As useful as a tool as this can be, you can't expect it to deliver the same results as butyl sound deadeners. Also, it should be noted that it produces a harsh smell that can stick around for a while, and it should be applied in layers, meaning you may need more than what's included here to achieve desirable results. 

This product can cut down noise, but also serves as a thermal barrier and the price makes it hard to ignore. 

We're wrapping up our list with another alternative to butyl sound deadeners. This product, this time from Noico, actually features a closed foam design that helps it to achieve a few things. First and foremost, it can take noise down a decent amount and secondly, it can also serve as a thermal barrier to keep the cabin cooler in the summer and warmer in the winter. Of course, there's a lot to love about the price point, but it does deliver despite what expectations may be. 

On top of that, it doesn't absorb moisture and features an incredibly strong adhesive backing that isn't sure to peel away any time soon. There is also no smell associated with this product. The double-edged nature of the backing is where the flaws start, though. It's strong enough that the foam can tear after placement, meaning you need to take your time with installation. We should also mention that this doesn't work as well as butyl and often serves as a layer above it to achieve desirable results. 

Let's get down to it. Dynamat started the industry of sound-deadening insulation cars back in 1989. The product was a solution to problems car owners of all shapes and sizes dealt with, and it's only natural for an idea like this to catch on. It's also only natural for everyone and their brother to start up a company and try their hand at it. 

Before we leave you with the impression that we're saying Dynamat is the only sound-deadening company to go with, we should say that a lot of the competition is worth considering. We even have some experience with them and are pleased with the performance. As we assembled our list, we made sure to include those we know to work well, that actually stick to panels you need them to, and those of different configurations so that you have options to sort through. 

Our product selections, rankings, and awards for this story are based on research. While we haven’t conducted real-world testing on all of these products yet, we’ve looked at consumer testimonials and data, tutorials, and general discussions on social media and in forums. We also consider price and specification in the context of the segment. And, of course, we rely on our institutional knowledge of the automotive landscape to weed out weak products.

It's easy to say we picked what we picked because we like it, but it's another thing to really dive into the thought process. That's why we want to walk you through a buying guide for sound deadener insulation. Not only that, but as you learn more about sound deadener, you might find what's on our list doesn't quite suit your needs. This guide is here to help you track down what will. 

Savants of this part of the industry might get a little peeved to see that we're lumping foam into the discussion of sound deadening, and we have to agree that they're right about the differences. However, we want to keep newcomers in mind. When it comes to controlling sound in your car, you'll have a few different materials to choose from. The brief explanations below will help to understand what is better and when. 

True sound-deadening materials rely on butyl rubber. The goal this material works to achieve is cutting down vibrations and acoustics in panels. It's going to cut down on the sounds of rocks hitting the wheel wells, exhaust noise polluting the cabin, and so on. It's also a great choice for enhancing the performance of sound systems as it won't harm bass or other airborne frequencies. 

The material is a tacky, pliable compound that easily adheres to bare panels. It's often coupled with an aluminum foil backing and typically comes in sheets. You will need to use a roller to apply it to uneven surfaces for the best results, but it generally won't pull away easily after installation. 

As you shop, you will come across materials that rely on closed foam materials. While it works to achieve a similar goal of cutting down noise, it's not dealing with the same elements as butyl. Instead, it's designed to tackle airborne sound waves. Issues like the sound of passing cars and other noise from outside of the vehicle are what it's intended to deal with. 

The issue with foam is that it can begin to interfere with sound quality within the cabin if it isn't used effectively. However, that doesn't mean one is universally superior to the other. If you're looking to get a truly luxurious feel from your car, you will need to use both with strategic placement. 

There aren't many spray-on sound deadeners out there, but they are worth mentioning, as they can be a useful tool. The texture is close to a rubberized undercoating, and unlike butyl or foam technologies, they spray right out of a can, eliminating the need to cut pieces to size. 

While these products will reduce noise, it's important not to use them in place of foam or butyl sound deadening. Instead, you should use this where the others can't reach. Exterior portions of the vehicle, tight spaces or gaps between other sound reduction materials are easily covered with the spray-on sound deadener.

Now that you know the different types of sound deadeners, let's dive into some of the key features. These are the areas to keep in mind as it's what determines the right choice for your car. Don't worry, though — it's not as complicated as it can seem. 

It can seem redundant to dive back into materials after highlighting the different types. However, we didn't discuss much about what to use and where just why you might consider different materials. 

For the most part, you want to apply a butyl sound deadener to the floor pans, package trays, roof panels, and other structural panels that produce excessive vibrations.  If you're trying to cut down noise completely, a layer of foam sound eliminator can also be applied to the floorboard, but is often used behind door panels and other areas where outside noises can come in. It's also a good idea to read into what sound experts suggest for your exact make and model to get the best results. 

The thicker the material, the better of a job it can do at cutting down unwanted noise. When it comes to true sound deadener, 50 mil is the standard, 80 mil is the middle of the road, and anything over 100 mil is supreme. Which is right for you depends on how bad your noise issue is and how quiet you really need things to be. Some drivers still want some road noise, so the choice is yours. 

Foam materials are naturally much thicker, but the same school of thought applies. However, it's important to remember that the thicker the material becomes, the harder it can be to tuck into certain parts of the car. 

Cars generate heat — that's just a fact. You're riding down the highway on an automobile that produces motion with explosions. That heat can easily turn your efforts into a sticky mess that does little to combat the noise issue. 

The engine and exhaust aren't the only offenders. Sun beats on the roof, the transmission gets hot as it runs, and so on. The point is that you need to be considerate of any sources of heat and pick a material that's designed to live in the type of environment you need it to. 

Now that we have the basics out of the way, your selection comes down to research. We recommend reading what experts and other enthusiasts say about what works for your application and go from there. It's really pretty simple stuff, but we do have a few quick tips to help you get the most out of whatever product you decide to go with. 

Sound deadener works. Whether or not it belongs in your car depends on your use of the vehicle. If you're using the vehicle for street use, then yes, sound deadener is worth it. Even if you're concerned about adding weight to the vehicle, you can use strategic placement to cut down on harsh vibrations. 

Yes, you can sound deaden a hood. One technique involves using a base layer of sound deadener covered by a hood insulation material. There are also kits designed specifically for sound deadening your hood. 

Sound deadening can improve the bass of your sound system. Using it can dramatically improve your sound system's performance on all levels, which is why many people want it in their cars in the first place.

Yes. Your trunk might seem like its own entity, but it is a part of your vehicle's cabin nonetheless. Neglecting to apply sound deadener here can be detrimental to your efforts to improve comfort or sound system performance.  

It's hard to ignore the performance and quality Dynamat 10455 18" x 32" x 0.067" Thick Self-Adhesive Sound Deadener with Xtreme Bulk Pack brings to the table. However, the Kilmat 80 mil 36 sqft Car Sound Deadening Mat is an excellent choice on a budget.  

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