ResoNix Sound Solutions

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ResoNix Fiber Mat 45 – 45mm Thick Automotive Sound Absorber & Decoupler – Self-Adhering & Hydrophobic (13.5 Square Feet)

ResoNix Fiber Mat is the ultimate automotive sound absorbing and decoupling product. It features the smallest fibers out of any fibrous sound absorber on the market, and is constructed in a way that, when combined, defies what most thought was possible for sound absorption relative to its thickness. It also features an automotive grade peel-and-stick adhesive for easy installation.

Made In America.


Quantity Discount Type Discount Price Per Item
4-9 Percentage 10 $112.50
10-25 Percentage 20 $100.00

ResoNix Fiber Mat 45- 45mm Thick Automotive Sound Absorber and Decoupler


       ResoNix Fiber Mat 45 is a 45mm (+/- 1mm) thick, 54″ x 36″ (13.5 Square Feet) automotive sound absorber that is comprised of hydrophobic polypropylene fibers featuring an automotive-grade peel-and-stick adhesive on one side, and is used in aftermarket automotive installations to serve a few purposes. First, to absorb any incoming external noise, such as wind, tire, and road noise. Second, to decouple one panel from another. It can also act as a superior air gap/decoupling layer for a noise barrier such as ResoNix Barrier. And lastly, it is a great heat insulator, with an R-Value of 7.15. Due to the material it is comprised of, it is naturally hydrophobic and is completely mold/mildew resistant. This can be used anywhere in a vehicle without worry.

       ResoNix Fiber Mat features an automotive-grade adhesive to allow for an easy and lifetime-lasting install. ResoNix Fiber Mat is an automotive sound absorber that works via the microscopic fibers that convert the passing acoustic energy into mechanical energy (the moving of the fibers) and thermal energy, from the friction of moving through the scattered fibers. It being so soft and plush also offers it to not just being an automotive sound absorbing mat, but also acts as an excellent decoupler that can be used in doors, rear decks, and anywhere else you can fit it. It is a better decoupler than any Closed Cell Foam on the market as it is extremely soft and compliant and is highly suggested to be used on any larger panels. Due to the nature of the product, we still offer our CCF7 to handle the decoupling of small panels and to spot-treat certain areas.


How does it work as an automotive sound absorber? Here is an excerpt from our Reference & Information Guide

       First, sound absorption happens when you convert acoustic energy into another form of energy, such as mechanical or thermal. It only makes sense to use a soft, fibrous or porous absorber in a vehicle, so we will stick with how those work. The fibrous materials absorb sound by deforming randomly at a microscopic level as sound passes through. The porous materials absorb sound by creating friction against sound waves as they pass through.


What makes our products better than the rest? Click here for a detailed run down on why ResoNix is the best option.


Where should ResoNix Fiber Mat be used?

Fiber Mat 45 Automotive Sound Absorber & Decoupler Installation Suggestions: 

Note: For Automotive Sound Absorbing Mat purposes, Fiber Mat 45 is always better to use if it can fit. Every car and every application is different. This is only a list of suggestions based on our experience. What may work best for your situation may be different. It is up to you to figure out what can fit in your vehicles locations. Fiber Mat 45 is always a better choice if it can fit, but if the suggested locations have a tighter tolerance than normal, it is suggested to use Fiber Mat 25 will fit properly. 

In between door panels and the inner door skin as a decoupler, replacing commonly used closed cell foam to eliminate pesky rattles from the doors. It also acts as an absorber here for outside wind/tire/road noise, as well as astray midbass frequencies from door-mounted speakers.

Rear Decks

Use ResoNix Fiber Mat 45 in between rear deck panels and the metal underneath if fitment allows. This serves as an excellent decoupler to eliminate rattles caused by sound systems which cause muddy and distracting bass from trunk-installed subwoofers.


One of the more common locations, use ResoNix Fiber Mat 45  in your headliner to absorb and eliminate the largest source of wind noise, the roof. This will also help improve low-frequency transient response in vehicles being built for high-end sound systems. 

Wheel Wells

Use this on the inside of your fender liners (hidden side), or on the metal body of the wheel well. This will greatly reduce noise from tires and wind from entering the cabin.

Interior Firewalls

Again, due to it being able to fit in tight areas, Fiber Mat 45 is the perfect choice to fit on an interior firewall to absorb noise and heat from entering the cabin from the engine bay.


A, B, & C Pillars all benefit from the installation of ResoNix Fiber Mat to help with decoupling rattles and absorbing wind noise that are common from these areas.

Remember, every car and every application is different. This is only a list of suggestions based on our experience. What may work best for your situation may be different. It is up to you to figure out what can fit in your vehicles locations. Fiber Mat 45 is always a better choice if it can fit, but if the above locations have tighter tolerances, use ResoNix Fiber Mat 25 instead. 

 Things To Note About ResoNix Fiber Mat Automotive Acoustic Material.

Hydrophobic and mold/mildew resistant. Water is of no concern for this product.

.  Cutting the product with heavy duty scissors and will usually create a sealed edge. Open edges are fine, but if agitated, this can cause fibers to pull out of the opening. Do NOT cut with a razor blade or box cutter. It will not cut cleanly. Scissors only. 

.  Use INSIDE of doors on outer door skins at your own risk. 

.  Our automotive sound absorbing mat absorbs sound best when left uncompressed. Having it compressed in certain tight areas is fine, especially for decoupling purposes, but do not try to stuff areas as tight as possible if your goal is acoustic absorption. It wastes product and decreases its overall acoustic absorption performance.
. Remember, what makes one fibrous acoustic absorber better than others comes down to its construction. The smaller the fibers, and the less they support each other, the easier it is for sound energy to cause them to vibrate. This transfer of energy is the exact event that is required to reduce sound. This means that the product is by nature weak, and easy to tear apart. The peel and stick adhesive that it features is very easy to peel from the base if you are not careful. This is not a defect. This is just the nature of a product where you are designing it to be able to absorb as much sound as possible. Adding any resins to the mix to strengthen the non-woven mat would drastically reduce acoustic absorption performance. Using a weaker adhesive would have no effect on needing to be careful when peeling the paper backing. 



ResoNix Fiber Mat 45 Specifications

.  45mm thick at rest and compressible down to about 7mm. Please note that it may come out of the shipping box thinner than this. It will expand back to normal over time and as you cut and work with it.

.  54″ x 36″

.  1215 grams per sheet (2.677 pounds)

.  R-Value: 7.15

.  All edges now come sealed. Cutting with scissors is perfectly fine and will create a sealed edge in most cases. Even if it doesn’t, the material will be okay and moisture will still not be an issue

.  Automotive-grade peel-and-stick adhesive backed for easy installation

.  Sound Absorption Coefficient tested to ISO 354 standards

ResoNix Fiber Mat 25 & 45 vs. 3M Thinsulate au4020/sm600l - ISO 354 Test - Results Overlaid

ResoNix Fiber Mat Installation Examples

ResoNix Fiber Mat 25 & 45 Data Sheets

Sound Absorption Coefficient tested to ISO 354 standards

USA Manufactured

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