Car Sound Insulation: The Best Way to Soundproof a Car

Car Sound Insulation: The Best Way to Soundproof a Car

Tired of hearing road, wind, and engine noise while you’re cruising on the highway? Welcome to our Ultimate Guide to Car Sound Insulation.

Want your car to feel more refined and upmarket? We have the solution for you in a complete DIY guide so you don’t need to pay for a car sound-deadening service.

How to make your car quieter inside

We’ve written a series of articles on Car Sound Insulation to which you’ll find links in each of these articles. They work together and we advise you to read them all.

This guide you’re reading now brings them all together to help you learn how to make your car quieter inside.

The Best Way to Soundproof a Car

In this manual, we’ll cover how you can sound deaden your car to an extent that your cabin will become silent in a way you will not believe. We’ll teach you the best way to soundproof a car and which are the best car noise insulation materials so you don’t have to spend money hiring a car soundproofing service.

Automotive sound-deadening materials serve different aims. You have a lot to choose from damping materials, sound blockers, and sound absorbers.

Check this specific topic to learn deeply about this subject: How to Reduce Noise in Car Interior

Now let’s dive further into automotive sound insulation;  we’re going over the best automotive sound-deadening materials and products.

Table of Contents

  1. How to make your car quieter inside
  2. The Best Way to Soundproof a Car
    1. Damping materials
      1. Dynamat Xtreme Bulk Pack
      2. Second Skin Damplifier Pro
      3. Noico Butyl Mats
      4. Kilmat Butyl Sound Deadener
      5. FatMat Rattletrap
      6. Second Skin Audio Spectrum
    2. Noise barriers
      1. Second Skin Luxury Liner
      2. Second Skin Luxury Liner Pro
      3. Stinger RKCP12 RoadKill Carpet Pad
      4. Siless Liner 314 mil
    3. Sound Absorbers
      1. Second Skin Mega Zorbe
      2. Uxcell Acoustic Foam
  3. Conclusion

Damping materials

Inside your car cabin, there is a lot of structure-borne noise coming from sheet metal panels. The floor pan, doors, roof, and other metal surfaces act as sound amplifiers. Vibration-deadeners, work by absorbing sound-causing vibration energy, eliminating resonance, and baffling out the excessive sound.

Most common vibration dampers come in form of butyl rubber mats bonded to an aluminum alloy skin. They stick to the inside surface of your car’s metal panels and are easy to stretch and contour.

There are also vibration dampers made from tar with adhesive backing, instead of butyl, which are usually more affordable, although heavier and thicker. Some can also leave some kind of smell when exposed to extreme heat and they’re not so easy to contour as the butyl mats.

You can also opt for a car sound insulation spray of liquid butyl and other elastomeric damping polymers. Their purpose is to be used in hard-to-reach areas of the vehicle and also for undercoating sound deadening, engine bay, and wheel wells.

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Dynamat Xtreme Bulk Pack

Key features:

  • 9 sheets (36 sq.ft)
  • 18 x 32 x 0.067 inches per sheet
  • Aluminum-coated for heat resistance
  • Self-adhesive butyl rubber material

High-performance Dynamat Xtreme is lighter than Dynamat Original and four times more effective. It doesn’t require heat and is extremely easy to install, being very moldable. It is recommended for vehicle tops, sides, floor, and engine bay.

Dynamat Xtreme is coated with aluminum for high-temperature areas such as firewalls and roofs, making an excellent thermal barrier.

The Bulk Pack contains nine 18″ x 32″ pieces of Dynamat Xtreme for rear decks, doors, floors, and trunk floors. Unlike Dynamat Original and some other materials from other manufacturers, Dynamat Xtreme is also recommended for trunk lids, roofs, quarter panels, and under-hood installations.

To learn how to install dynamic in trunk, doors, or floor, check out our awesome article on reducing tire noise in your car.

It is one of the best quality vehicle sound insulation materials you can buy when sound-deadening your car.

Pros:

  • Very light yet extremely effective damping material
  • Huge heat blocking capabilities
  • Extremely easy to install

Cons:

  • One of the most expensive damping materials available

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Second Skin Damplifier Pro

Key features:

  • 22 sheets (36.5 sq.ft)
  • 12×20 inches per sheet
  • 80 mil thick elastomeric butyl and 6.5 mil black annealed foil constraint layer
  • Thermal range of -75°F(-60°C) to 450°F(232°C)
  • Aluminum-coated for heat resistance
  • Self-adhesive butyl rubber material

Alongside with Dynamat Xtreme, these butyl-rubber mats are the best performers and the most efficient materials you can buy to sound-deaden your vehicle. It claims to be 300% more efficient than tar boards and asphalt mats.

The true performance of Damplifier Pro comes from details you cannot see, such as the unique chemistry of the high-performance US-made butyl rubber. Damplifier Pro is made of 2 mm thick elastomeric butyl rubber with a 6.5 mil black annealed foil constraint layer.

The thermal range is -75°F(-60°C) to 450°F(232°C). and will not melt, out-gas or fall off, ever. Damplifier Pro is ROHS compliant, an EU standard restricting the use of 10 hazardous substances.

This damping material comes in handy size sheets which make it easier in terms of cutting, making the installation process easy. Damplifier Pro is recommended for trunk lids, roofs, floor, doors, wheel wells, and under-hood installations.

Pros:

  • High-quality US-made elastomeric butyl rubber
  • Very light yet extremely effective damping material
  • Highly efficient thermal barrier
  • Amazing thermal range of -75°F (-60°C) to 450°F (232°C)
  • Easy to install

Cons:

  • It’s expensive

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Noico Butyl Mats

Key features:

  • 9 sheets (36 sq.ft)
  • 29,5×19,5 inches per sheet
  • 80 mil thickness
  • Total weight of 0.7 lbs/1sqft
  • Aluminum-coated for heat resistance
  • Self-adhesive butyl rubber material with some asphalt undercoating

Noico provides one of the lowest prices for 80 mils automotive butyl and aluminum foil sound deadening. You are not just buying an excellent quality product but also saving a lot compared to other brands, being a more cost-effective solution yet offering quality soundproofing results.

This self-adhesive insulation material consists of butyl with an aluminum foil at the top. It has a total weight of 0.7 lbs/1sqft. This weight ensures maximum efficiency.

Noico has a special indicator to ensure it is installed correctly. The special embossing on the foil must be rolled out with a roller till it is plain smooth, then you’ll be 100% sure that the insulation is set correctly and professionally.

The sound damping mats come in handy size sheets which make it easier in terms of cutting, and helping with the installation process. It is recommended for doors, hood, floor, roof, trunk and trunk lid, and the interior side of the wheel wells.

Pros:

  • Easy to install
  • Very affordable price
  • Special installation indicator

Cons:

  • Some slight rubbery smell when installing

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Kilmat Butyl Sound Deadener

Key features:

  • 34 sheets (36 sq.ft)
  • 9.8×15.7 inches per sheet
  • 80 mils thickness
  • Total weight of 0.5 lbs/1sqft
  • Aluminum-coated for heat resistance
  • Self-adhesive butyl rubber material

Kilmat is another very affordable solution to sound-deaden a car. It claims to have the lowest price on the market for 80 mils automotive butyl and foil sound deadening.

It is also self-adhesive and weighs about 0.5 lbs per sq.ft, making it not only cheaper but also lighter than Noico.

Like Noico mats, the special embossing on the foil must be rolled out with a roller until it is plain smooth, then you’ll be 100% sure that the insulation is set as it should.

Also, the sound damping mats come in very small size sheets which make it easier in terms of the cutting and installation process.

Another point in favor of the product is not only is it an effective noise insulator, but it’s also an effective heat blocker. This is a double win. Or triple, considering the price. This product offers all the benefits of Noico at even a lower price, being a better alternative.

Pros:

  • The most affordable on the test
  • Very easy to install thanks to small-sized sheets
  • It’s odorless
  • Thick and lightweight

Cons:

  • The material is relatively stiff which makes it more difficult to cut

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FatMat Rattletrap

Key features:

  • 50 sq. ft roll
  • 18×33,5 inches per sheet
  • 80 mil thickness
  • Aluminum-coated for heat resistance
  • Asphalt-based mat with patented “Super-Stick” Adhesive
  • Install Kit consisting of easy instructions, knife, roller, and FatMat sound control decal

FatMat Rattletrap comes in the form of a 50 sq. ft roll. It’s not a butyl mat, it’s made of an asphalt-based rubbery compound instead, which is not as effective as butyl considering the same thicknesses and weight.

This is what truly differentiates it from Dynamat, Second Skin, Kilmat, and Noico. Nonetheless, Fatmat makes for a fairly priced soundproofing alternative.

RattleTrap stops annoying rattles, eliminates vibrations, and reduces road noise, engine noise and exhaust drone in your car. It has patented “Super-Stick” pressure-sensitive adhesive backing with a heat-resistant aluminum surface, for improved efficiency in heat blocking.

Being an asphalt-based mat, it can melt if exposed to very high temperatures and emit some smell. There are instances of people complaining about Fatmat melting at high temperatures and creating a mess.

However, if you live in a place that has cold weather conditions throughout the year, the Fatmat deadeners are a great option.

FatMat it’s not the most expensive, nor is it the cheapest. It’s not the best in regards to overall quality, but it still gets the job done quite well.

Pros:

  • Aluminum coating for improved heat blocking
  • Comes with a complete installation kit
  • Very powerful adhesive
  • It’s affordable

Cons:

  • May smell or even melt if exposed to very high temperatures

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Second Skin Audio Spectrum

Key features:

  • 1 gallon
  • Heat resistant up to 400ºF
  • Odorless when dry
  • Water and flame resistant
  • Blue when wet, black when cured
  • Layerable

This is a fantastic water-based coat-type noise and resonance reducer that can easily be painted to match your car’s finishing. It’s also ideal for those hard to reach places where you can’t stick the usual damping sheets.

Spectrum Liquid Sound Deadener is a viscoelastic polymer formulated by Second Skin Audio for top-of-the-line vibration damping and adhesion. The acrylic polymers in Spectrum have been selected to reduce sheet metal resonance, stick to just about anything, and meet all safety standards.

It is odorless, rustproof, waterproof, flame-resistant, chemical resistant, non-toxic, and dries with a seamless, black finish. Spectrum can be applied with a spray gun, brush, or roller.

For large surfaces or hard-to-reach areas (like the undercarriage and inside the wheel wells), spraying on Spectrum can be much easier than applying sound deadening mats.

This product is layerable to match the area’s sound deadening needs and it is recommended to be applied in 1mm layers. It is easy to clean up with water within 30 minutes.

Spectrum is designed to adhere to metal but will stick to just about any cleaned surface besides plastic or a high gloss surface without a primer. You can safely use it in the engine compartment, wheel wells, on the underside of the vehicle, and everywhere inside the cabin.

Pros:

  • Excellent for hard-to-reach areas
  • Temperature rated to 400º F
  • Non-toxic and easy to clean up with water
  • Can be used on the underside of the car, wheel wells, and engine compartment

Cons:

  • You need to apply some layers of it to achieve the same effect as the Damplifier Pro sheets

Noise barriers

Sound blockers act as airborne noise barriers. They work the best as an addition to the sticky butyl rubber and tar mats mentioned above.

Noise barriers are usually made of thick foams, hard rubber, or mass-loaded vinyl (MLV). Mass loaded vinyl is a high-quality noise abatement material that can substantially decrease the noise level inside your car cabin.

As a plus, sound blocking materials also act as effective thermal barriers.

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Second Skin Luxury Liner

Key features:

  • 9 sq. ft (24 x 54 inches)
  • 1/8 inch thickness
  • 1 lb per sq. ft
  • MLV Sound Barrier

Luxury Liner is the most affordable Mass Loaded Vinyl (MLV) mat from the premium brand Second Skin. It is just a heavy vinyl sheet without any layer of foam coupled to it.

It’s a 1/8 inch thick MLV noise barrier designed to block out unwanted noises and ideally sized for smaller projects (automotive, generator box, cabinets, HVAC). It is flexible and pliable to withstand significant bending (600 psi is over 3x the tensile strength of some MLV).

For automotive applications and improved results, combine with a layer of closed-cell foam. It’s suitable to cover your car’s firewall (cabin side), floor, and trunk. It’s odorless and meets federal fire safety standards (FMVSS 302).

Pros:

  • High-quality, heavy MLV
  • It’s odorless
  • Meets federal fire safety standards (FMVSS 302)

Cons:

  • The most affordable vinyl barrier from Second Skin, but still, it’s pricey

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Second Skin Luxury Liner Pro

Key features:

  • 9 sq. ft (24 x 54 inches)
  • 3/8 inch thickness
  • 1.25 lb per sq. ft
  • MLV Sound Barrier with Closed Cell Foam
  • Heat resistant up to 180 F

Luxury Liner Pro is the top-of-the-range Mass Loaded Vinyl (MLV) barrier from Second Skin and it’s one of the most efficient products on the market in its category.

It’s designed to stop road, exhaust, and engine noise from entering your vehicle and can be used in cars, vans, all-terrain vehicles, SUVs, trucks, etc.

By fusing a raw virgin mass-loaded vinyl (MLV) noise-blocking product with a decoupling layer of high-density closed-cell foam, this automotive insulation sheet will block sound about as well as a wall in your house.

Luxury Liner Pro is odorless, flexible, and heat resistant up to 180 F. Its high R-value (4.45 per inch) makes it an excellent heat insulation mat.

Use this product to cover your car’s firewall (cabin side), floor, and trunk. Do not use this product on the roof, hood, or anywhere in the engine compartment. Luxury Liner Pro meets all automotive safety standards, is designed to be self-extinguishing, and has a Class A fire rating.

Pros:

  • The most effective MLV you can buy
  • Heat resistant up to 180º F
  • Excellent heat insulation properties
  • Class A fire rating

Cons:

  • It’s very expensive

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Stinger RKCP12 RoadKill Carpet Pad

Key features:

  • 12sq.ft (32 x 54 inches)
  • Dual-layer construction
  • 3-Way stretch vinyl
  • Colour: grey

RoadKill Carpet Pad is specifically designed to eliminate road noise from floorboards, and trunks. It’s a great alternative to some most expensive brands as its cost for sq. ft is incredibly lower. This product grants a huge reduction in low-frequency road noise which reduces driving fatigue

It combines ¼” semi-closed cell high density, energy absorbing foam with a high-mass butyl-vinyl decoupling layer for maximum performance.

This combination provides for heavy damping properties over a wide range of frequencies and also mass loads the surface it is applied to suppress vibrations and block exterior airborne noise.

It is designed to be applied under the factory carpet, on the floor, and in boot areas.

Pros:

  • It’s very affordable
  • Doesn’t require adhesive
  • Easily cut to size using a utility knife or heavy scissors

Cons:

  • Not so effective and high quality as some more expensive products like Luxury Liner Pro

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Siless Liner 314 mil

Key features:

  • 15sq.ft (15.75 x 137.5 inches)
  • 314 mil / 8mm thickness
  • Heat resistant up to 215º F
  • Closed-cell PE foam with waterproof glue

Siless Liner is a good alternative to MLV products if your main concern is weight, installing space, and also the final cost. It’s not made from heavy vinyl, instead, it is made of oil and waterproof liner closed-cell polyethylene foam.

It certainly has not the same sound-blocking properties as the mass-loaded vinyl but does a good job with a fairly lower price, also being a lot more moldable and a lot less heavy than MLV.

It is a waterproof light-weight thermal deadener with a highly compressible closed cell foam formulation. This product doesn’t absorb moisture and has no odor. It’s also very flexible which makes it easy to install with or without a roller.

Siless Liner is a very versatile insulation material with excellent thermal barrier properties. helping blocking engine, exhaust, and solar radiation heat, ensuring your vehicle stays cooler in the summer and warmer in the winter.

You can use this product anywhere in your car’s interior, from the metal sheet of the roof to the inside fascia of the door cards and other plastic trim pieces.

Pros:

  • Very affordable material
  • Lightweight and flexible
  • Great thermal barrier properties
  • Waterproof and heat resistant up to 215º F

Cons:

  • It’s not the best sound barrier

Sound Absorbers

Installing sound absorbers is the last step of your entire sound-deadening process. This type of material won’t block exterior noises from entering your vehicle.

Its key function is to absorb interior airborne sound waves and cut some medium to higher frequencies, creating a more comfortable car environment, and reducing interior noises and echoes.

Open-cell foam is an excellent material for absorbing mid-to-high frequency sound waves.

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Second Skin Mega Zorbe

Key features:

  • 8 sq. ft (1 sheet)
  • 1/2 inch thickness
  • Adhesive backing
  • Hydrophobic melamine foam
  • Thermal range: -40 F to 350 F

Absorbing noise that’s already in the cabin is the last step of any vehicle soundproofing project. Mega Zorbe is an aerospace-grade, lightweight melamine foam sheet with excellent physical properties, making it ideal for both sound and thermal insulation.

Open-cell foam is the best sound-absorbing material for absorbing high and medium-frequency sound waves in your vehicle.

With a high sound absorption coefficient and r-value (4.16/inch), Mega Zorbe will improve acoustics in the door cavity or add roof insulation above the headliner.

Meets all aerospace, transportation, and construction standards for fire, smoke, toxicity, and water resistance. Each sheet includes high-temperature peel and sticks adhesive backing.

This product is ideal to use in the roof, doors, and inside plastic interior trim such as pillars, dashboard, etc. It’s not recommended to use this product in heat bays or near heat sources.

Pros:

  • Great sound absorption capabilities
  • Big thermal range
  • Hydrophobic
  • Adhesive backing available

Cons:

  • None to state

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Uxcell Acoustic Foam

Key features:

  • 4.3 sq.ft (19.7 x 31.5 inches)
  • 0.4-inch thickness
  • Waterproof and moistureproof
  • White sound-absorbing cotton

Uxcell offers this inexpensive sound-absorbing foam. It absorbs resonant noises and also helps to block high-frequency sound waves, improving vehicle acoustics. It will also ensure your vehicle stays cooler in the summer and warmer in the winter, making your ride more comfortable.

It’s composed of technical pressure nodes of cotton, a short fiber dustproof layer, and a superfine fiber sound-absorbing insulation layer.

This Uxcell acoustic foam is suitable for use in the hood, doors, roof, trunk, inside plastic trim panels, and also in the hood and on the wheel wells.

Pros:

  • It’s affordable
  • Easy to cut and install
  • Waterproof and moistureproof
  • Does a decent job absorbing sound waves

Cons:

  • Doesn’t feature an adhesive backing

Conclusion

Those are some of the key products you have to choose from, to achieve a great result when sound deadening your vehicle.

When choosing a damping material, if you aim to use the best, most effective, durable, and reliable product, Dynamat Xtreme and Second Skin Damplifier Pro are the absolute best quality mats on the market, hands down.

However, for a lot less money, you also have other great options to choose from. Kilmat combines an effective and good quality butyl-rubber mat at a very affordable price for cheap car sound insulation. It’s our choice for the best value damping mat.

Second Skin Audio Spectrum it’s ideal for those hard-to-reach places where you can’t stick the usual damping sheets.

Regarding the noise barriers, Second Skin Luxury Liner Pro offers the most efficient product, combining a thick vinyl mat with a layer of closed-cell foam for absolute quietness. Stinger is our choice for the best value noise barrier. For the RKCP12 Roadkill you can expect good performance for a great value.

In the sound absorbers department, the Mega Zorbe from Second Skin is awesome and it’s our best recommendation. Although, for a lot less money and yet with some good results, Uxcell Acoustic Foam is also a product to consider.

For more detailed information on sound deadening and to learn how to make your car quieter, check out our specific resources: