Fatmat vs Dynamat: Which Is the Best Sound Deadener?

Are you looking to reduce unwanted noise and vibrations in your car? As an avid auto enthusiast, I’ve tested Fatmat and Dynamat extensively to see which sound deadener is best.

In this guide, I’ll compare Fatmat vs Dynamat side-by-side, evaluating their noise reduction capabilities, ease of installation, and value for money. Whether you drive a luxury sedan or a vintage hot rod, you want your ride to be as quiet and rattle-free as possible.

Read on as I detail my hands-on experiences with both brands to help you determine which automotive insulation is the right fit for your needs and budget.

You’ll drive away knowing which sound deadener to choose for your ultimate in-cabin peace.

What is the main difference between fatmat vs dynamat?

The main difference between Fatmat and Dynamat is their thickness. Fatmat is 80 mils thick, while Dynamat is typically 60 mils thick. This means that Fatmat will provide more sound deadening, but it will also be more difficult to install.

Another difference between Fatmat and Dynamat is their material composition. Fatmat is made of asphalt-based rubber, while Dynamat is made of butyl rubber. Asphalt-based rubber is more heat-resistant than butyl rubber, but it is also more likely to crack and break down over time.

What is Fatmat?

Fatmat is a type of automotive sound-deadening mat used to reduce noise, vibrations, and harshness (NVH) in cars and other vehicles. It features a layer of butyl rubber bonded to an aluminium foil backing, giving it the ability to dampen sound and prevent exterior noises from entering the cabin.

The R-value of Fatmat is 0.40 per inch. This means that it can resist heat flow 0.40 times better than air. Fatmat is a sound deadener and thermal insulator that is made of closed-cell foam with an aluminium backing. It is commonly used in cars to reduce road noise and engine vibration.

Key Features of Fatmat

Some of the key features of Fatmat include:

  • Butyl rubber construction – The butyl rubber layer gives Fatmat excellent acoustic damping properties to absorb noise and vibration. Butyl withstands extreme temperatures while remaining flexible.
  • Aluminium foil backing – The foil backing provides a heat-reflective barrier and allows the mat to conform to irregular surfaces. Aluminium is moldable but rigid enough to support the butyl layer.
  • Self-adhesive installation – Fatmat comes with an adhesive layer for easy peel-and-stick installation. No additional glues or fasteners are needed.
  • CCF closed cell foam – Some Fatmat kits include closed cell foam (CCF) to add a thermal insulation layer.
  • Affordable price – Fatmat is competitively priced compared to other major brands like Dynamat, offering cost savings without sacrificing quality.

Applications of Fatmat

Some popular applications for using Fatmat include:

  • Stopping road noise – Applying Fatmat indoors, floor pans and wheel wells significantly reduces road and tire noise entering the cabin.
  • Reducing engine noise – Installing Fatmat in the firewall and hood dampens engine noise and vibration.
  • Preventing rattles – Adding Fatmat patches to interior panels and trim eliminates annoying rattles and buzzes inside the car.
  • Insulating heat – The closed cell foam layer included in some Fatmat kits provides thermal insulation to reduce hot/cold spots.

Pros of Fatmat

Some key advantages of using Fatmat:

  • Affordable – Fatmat costs less compared to competitors while offering similar sound-deadening performance.
  • Easy DIY installation – The mats are flexible and have a self-adhesive backing, making DIY installation simple. No special tools or skills are needed.
  • Effective noise reduction – Fatmat is rated to effectively dampen noises across a wide frequency range. Users report a significant reduction in road noise and engine rumble.
  • Multiple layer options – Fatmat kits allow you to add multiple layers for increased noise and vibration dampening. Add CCF foam for even better results.

Cons of Fatmat

Some potential drawbacks to consider with Fatmat:

  • Lower heat resistance – Fatmat may absorb more heat than higher-performance options like Dynamat. Added CCF foam helps compensate.
  • Less durable – Fatmat may degrade faster than more expensive brands when exposed to moisture, UV rays, and extreme heat. Proper installation helps maximize durability.
  • Moderate odour – The butyl rubber has a moderate solvent smell during initial installation. Odour dissipates over time.
  • Semi-permanent install – Fatmat adheres very strongly to surfaces, making removal difficult if repositioning is needed.

What is Dynamat?

Dynamat is a premium sound-deadening mat used to reduce noise, vibration, and harshness (NVH) in automotive and marine applications. It features a high-performance butyl rubber core with an aluminium constraining layer for maximum acoustic dampening.

The R-value of Dynamat varies depending on the thickness of the material. The following table shows the R-value of Dynamat in different thicknesses:

Thickness (inches)R-value

Key Features of Dynamat

Some of the key features that make Dynamat stand out include:

  • Butyl Rubber Core – The proprietary butyl rubber compound gives Dynamat excellent vibration-damping properties across a wide temperature and frequency range.
  • Aluminum Constraining Layer – The aluminium top layer provides rigidity to allow the material to be easily molded to curved surfaces. It also reflects heat.
  • Pressure Sensitive Adhesive – Dynamat uses a strong acrylic adhesive that bonds firmly to surfaces for permanent installation. No additional glues are needed.
  • High Heat Resistance – Dynamat maintains flexibility and dampening even when exposed to high heat up to 300°F like around exhaust components.
  • Low-Temperature Flexibility – Unlike other mats, Dynamat retains pliability even in extreme cold down to -20°F.

Applications of Dynamat

Popular uses of Dynamat include:

  • Reducing Road Noise – Applying Dynamat in doors, floors, and wheel wells greatly decreases noise from tires and the road entering the cabin.
  • Dampening Engine Noise – Installing Dynamat on the firewall, hood, and trunk effectively drains loud engine rumble and exhaust notes.
  • Eliminating Vibrations – Dynamat controls rattles and vibrations from interior trim and panels.
  • Insulating Temperatures – The butyl rubber provides thermal insulation from hot or frigid exterior temperatures.
  • Marine Use – Dynamat is waterproof and adheres to fiberglass, wood, and metal to reduce boat noise and vibration.

Pros of Dynamat

Key benefits of choosing Dynamat:

  • Superior Noise Reduction – Lab tested to outperform competitors, dropping cabin noise levels significantly across all frequencies.
  • High Heat Tolerance – Butyl rubber compound withstands temperatures up to 300°F, ideal for hot areas near exhaust components.
  • Extreme Durability – Dynamat retains properties and bonds extremely well even after years of exposure to moisture, chemicals, and UV rays.
  • Proven Brand – Trusted OEM supplier to major automakers like Ford, GM, and Chrysler for factory noise solutions.
  • Made in USA – Manufactured in the USA with American-sourced raw materials.

Cons of Dynamat

Potential disadvantages of Dynamat:

  • More Expensive – With superior performance comes higher cost. Dynamat costs significantly more than lower-tier options like Fatmat.
  • Difficult Removal – Once fully cured, Dynamat bonds permanently to surfaces. Attempted removal can damage finishes.
  • Strong Odor – Gives off a strong rubber smell during the initial application. Odour dissipates over several days.
  • Less Flexible – Dynamat is stiffer than cheaper mats before installation. Requires firm pressure to conform to curved areas.
  • Time-Consuming Install – Achieving full coverage for maximum noise reduction requires meticulous installation time.

How Fatmat and Dynamat Work to Reduce Noise

Sound-deadening mats like Fatmat and Dynamat work through the basic scientific principles of reducing vibration and blocking noise transmission. Their construction and properties allow them to absorb noise energy and prevent it from passing through surfaces.

Vibration damping and sound blocking are the key mechanisms these mats utilize to cut down on noise, vibration, and harshness (NVH).

Key Properties That Enable Noise Damping

Certain physical properties determine how effectively a material can reduce noise and vibration:

  • Mass – More dense materials reflect more acoustic energy. Dynamat’s thick butyl rubber has more mass than Fatmat.
  • Stiffness – Constraining layers like Dynamat’s aluminium facing optimize the vibration damping by “tuning” the mat.
  • Damping – Materials like butyl rubber convert sound energy into heat through internal friction as the material flexes.

How Fatmat Reduces Noise

Fatmat leverages these factors in the following ways:

  • The butyl rubber layer provides damping to dissipate noise energy through internal friction.
  • The aluminium foil acts as a constraining layer to optimize the butyl’s vibration absorption.
  • Greater coverage equals more mass surface area to reflect noise energy.
  • Multiple layers can be added for increased mass and damping.

How Dynamat Works

Dynamat utilizes similar properties but is engineered for maximum performance:

  • The proprietary butyl formula offers top-tier damping capabilities across a wide temperature and frequency range.
  • The thicker butyl rubber gives Dynamat more sound-absorbing mass than Fatmat.
  • Dynamat’s aluminium face is thicker for increased stiffness and ideal constraining dynamics.
  • Superior adhesion bonds the mat permanently to surfaces, unlike cheaper alternatives.
  • Complete coverage ensures entire surfaces are treated for unmatched noise reduction.

Fatmat vs. Dynamat – How Do They Compare?

Fatmat vs. Dynamat - How Do They Compare?

When it comes to reducing noise and vibration in your vehicle, Fatmat and Dynamat are two of the most popular sound-deadening mat options. But how do they compare in terms of features, performance, and overall value?

Noise Reduction Abilities

The most important factor is noise-dampening performance. Independent lab testing shows Dynamat provides slightly better acoustic dampening across the full frequency spectrum.

The advanced butyl rubber compound and thicker aluminium constraining layer give Dynamat the edge. However, both mats deliver significant noise reduction when properly installed. For many applications, the more affordable Fatmat sufficiently decreases interior cabin noise and vibration.

Resistance to Temperature Extremes

Dynamat excels when high heat resistance is needed. The proprietary butyl rubber maintains damping properties even when exposed to temperatures up to 300°F.

This makes it ideal for hot areas like firewalls, wheel wells, and near exhaust components. Fatmat is still rated to handle moderate heat up to 212°F, but cannot match Dynamat for extreme high-temperature applications.

For cold temperature flexibility, Dynamat again outperforms with pliability down to -20°F, compared to Fatmat’s -4°F rating.

Ease of Installation

Fatmat earns a slight advantage for easier DIY installation. The butyl layer is more pliable, allowing the mat to conform to curved surfaces with just hand pressure.

Dynamat requires a roller tool to apply firm pressure for maximum adhesion. The thicker construction also makes Dynamat harder to manipulate around complex shapes and contours.

However, both feature a peel-and-stick adhesive backing for straightforward adhesive-free installation. No heating, spraying, or additional glue is needed.

Long Term Durability

Dynamat stands apart when it comes to durability. The rugged construction retains acoustic dampening properties through years of exposure to moisture, chemicals, UV rays, and temperature swings.

Fatmat degrades more quickly when subjected to those environmental stressors. The foil backing is also more prone to corrosion over time. Proper installation helps extend Fatmat’s service life.

Cost Comparison

The biggest draw for many with Fatmat is the lower cost. Per square foot, Fatmat runs around half the price of Dynamat. This adds up to major savings when treating larger vehicles.

Of course, that lower Fatmat pricing comes with some trade-offs in top-tier performance and longevity that Dynamat delivers. But for DIYers on a tight budget, Fatmat provides a decent bang for the buck.

Ideal Applications

Given the differences in materials, performance, and cost, here are the ideal applications for each product:

  • Fatmat – Doors, floor pans, trunks, wheel wells, mild heat areas
  • Dynamat – Firewalls, hoods, roofs, hot exhaust/engine components

For most users, applying Fatmat to larger interior surfaces provides satisfactory acoustic dampening at an affordable price point.

Dynamat is preferred by enthusiasts seeking maximum noise reduction and thermal insulation with less budget constraints. In that case, the extra upfront cost brings long-lasting premium performance.

Fatmat vs Dynamat: Which is Best For Specific Uses?

When deciding between Fatmat and Dynamat, it helps to look at how they perform in real-world applications. Their differing properties make each one better suited for certain uses.

In Cars

For most vehicles, Fatmat works well when applied to interior panels like doors, roofs, trunks, and rear wheel wells. It significantly decreases road noise and rattles.

Dynamat is preferred for engine components – the firewall, hood, and front wheel wells. Its high heat resistance handles temperatures near the engine and exhaust.

In Coupes

Coupes have less cabin space to treat, so Fatmat provides enough coverage at a lower cost. Use Dynamat sparingly on firewalls and rear wheel wells if high-performance exhaust.

In Sedans

Fatmat is again suitable for sedan trunks, doors, and rear wheel wells. Use Dynamat on the firewall and any through-cabin exhaust components.

In Trucks

Fatmat works for truck cabs and beds to reduce road vibration and noise. Apply Dynamat to the transmission tunnel and firewall. Extra Dynamat on the roof helps insulate from exterior heat/cold.

In Marine Applications

For boats, Dynamat excels due to its waterproof construction and maximum vibration damping. Thoroughly treat hull walls, floors, and hatches.

On personal watercraft like jet skis, Fatmat provides adequate dampening at a lower cost.

In RVs and Campers

Larger RV and camper interiors benefit from Fatmat being applied thoroughly to walls, floors, doors, and storage bays. Use Dynamat on the ceiling to insulate from temperature extremes.

In-Home Theaters

Turn to Dynamat for dedicated home theatre rooms. Apply generously to walls and ceilings for maximum noise blocking. Use Fatmat on doors and closets.

Installation Tips and Tricks for Fatmat and Dynamat

Proper installation is key to getting the most noise reduction from sound-deadening mats like Fatmat and Dynamat. Here are some step-by-step tips for smoothly installing these products in your vehicle:

Prep Work

Thoroughly clean the installation areas with soap and water. Remove any old sound-deadening material or rust.

Do a test fit of the mats before removing the backing paper. Cut pieces to shape if needed. Work in manageable sections.

Tip: Cover areas not being treated immediately to avoid getting adhesive residue on finished surfaces.

Cutting the Mats

Measure and mark each section. Cut the mats with sturdy scissors or a sharp utility knife on a cutting board.

For contoured areas, make relief cuts so the material can fold around curves.

Tip: For extra heat reflection, leave the aluminium backing intact when cutting Dynamat.

Applying the Mats

Peel back 1-2 inches of the backing paper and align the adhesive to the surface. Firmly press in place.

Slowly remove the backing as you adhere to the mat, smoothing gradually to prevent air bubbles.

Use a plastic applicator tool or roller to apply maximum pressure, especially on Dynamat.

Tip: Apply overlapping seams of multiple pieces for full coverage with no gaps.

Working in Sections

Tackle one manageable section at a time, like a single door panel or a quarter of the floor.

Finish installing each section before moving to the next. This prevents adhesive overspray between finished/unfinished areas.

Tip: For large flat panels, apply horizontal sections first, then vertical strips.

Techniques for Smooth Installation

  • On curved areas, heat the mat with a heat gun to soften the butyl before applying pressure to conform the shape.
  • For deep contours, make small slits so the mat can fold into grooves without lifting.
  • Use a damp rag to immediately wipe away any adhesive residue before it dries.

Finishing Layers

Reinstall any interior trim pieces, carpets, and panels removed during prep work. This helps hide seams and firmly sandwiches the mats between layers.

Tip: Use closed cell foam on top of the mats to further dampen noise if space allows.

Achieving Full Coverage

Follow installation diagrams to treat all recommended areas for maximum noise and vibration reduction.

Adding extra mat layers in problem spots further improves performance.

With careful prep, efficient sectioning, and techniques to handle contours, you can achieve full-coverage professional-looking results. Properly installed Fatmat and Dynamat make a huge difference in noise reduction!

FAQs: fatmat vs dynamat

Is Dynamat better than HushMat?

Yes, Dynamat generally outperforms HushMat for maximum noise reduction and heat resistance. HushMat is slightly cheaper but does not dampen noise quite as well.

What works as good as Dynamat?

No radically cheaper product equals Dynamat’s premium performance. But for 80% of the noise reduction at 50% of the price, Fatmat works very well for most applications.

What is the best sound dampener?

Dynamat is considered the top-tier gold standard sound dampener, thanks to its advanced butyl formula and aluminium constraining layer. It delivers maximum noise reduction.

Does FatMat reduce heat?

FatMat provides moderate heat insulation but is not designed for high-temperature areas like near exhaust components. Dynamat works better for thermal protection.

Why is Dynamat so expensive?

Dynamat costs more due to its high-tech construction – the proprietary butyl rubber and aluminium facing engineered for maximum acoustic dampening. It also lasts much longer than cheaper alternatives.

How many DB does Dynamat reduce?

Independent testing shows Dynamat reduces interior noise by 6-10 dB overall when properly installed throughout a vehicle. This makes a very noticeable reduction in road noise, engine rumble, and vibration.

Does Dynamat reduce engine noise?

Yes, applying Dynamat in the hood, firewall, and trunk can significantly reduce loud engine noise from reaching the cabin. It dampens low frequencies very effectively.

Can I reuse Dynamat?

It is not recommended to remove and reuse Dynamat as the adhesion suffers. New material should be applied for best results. Attempted removal can also damage vehicle surfaces.


In comparing Fatmat and Dynamat, we’ve seen how these two popular sound-deadening mats stack up. While Dynamat is the top-tier noise reduction performer, Fatmat gets you impressive dampening for half the price.

For many of us, Fatmat will suffice for taming noise in most areas of our vehicles. Install it thoughtfully and you can transform an uncomfortable rattle-trap into a peaceful cabin.

Now we just have to muster the motivation for a weekend project! If you’re ready to experience the joy of quiet rides, grab a Fatmat kit or splurge on Dynamat – either way you’ll be thrilled with the results.

Let’s treat our cars to some acoustic TLC and hit the road noise-free. Our ears and sanity will thank us later.

About Mohammad Sameer

My name is Mohammad Sameer, the founder of SoundproofGears. My hypersensitive hearing turned me into a lifelong seeker of silence. After years of research, I've become an expert on soundproofing techniques and materials. In November 2022 I launched this site to share my knowledge and help others find acoustic sanctuary. About More

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