ResoNix Sound Solutions

Premium Automotive Sound Treatment Solutions

ResoNix Fiber Mat 25 – 25mm Automotive Sound Absorber & Decoupler – Self-Adhering & Hydrophobic (13.5 Square Feet)


Quantity Discount Type Discount Price Per Item
4-9 Percentage 10 $89.10
10-25 Percentage 20 $79.20

ResoNix Fiber Mat 25 – 25mm Thick Automotive Sound Absorber and Decoupler.


ResoNix Fiber Mat 25 is a 25mm (+/- 1mm) thick, 54″ x 36″ (13.5 Square Feet) automotive sound absorber mat 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 third, it is also an excellent heat insulator, with an R-value of 3.99. 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 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 decoupling of small panels, and to spot treat certain areas.


How does ResoNix Fiber Mat 25 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 25 Automotive Sound Absorber 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

In between rear deck panels and the metal underneath. This serves as an excellent decoupler here to eliminate rattles which cause muddy and distracting bass from trunk-installed subwoofers. If Fiber Mat 45 Fits here in your vehicle, use that instead.


Use ResoNix Fiber Mat 25 here 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, due to less energy being able to reach and resonate the roof skin. 

Transmission Tunnels

Fiber Mat 25 is perfect for absorbing noise that radiates through the transmission tunnel while still easily fitting behind panels/carpet without issue.

Interior Firewalls

Again, due to it being able to fit in tight areas, Fiber Mat 25 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.


If applicable, the Fiber Mat 25 can be an excellent choice to use an absorber on the floor since it is able to be compressed thin enough to fit underneath most vehicles carpets to absorb outside noise entering through the floor. It is also an EXCELLENT decoupler/air gap for a noise barrier. If you can fit it, using this between the floor and a noise barrier such as ResoNix Barrier will greatly improve the barriers ability to block outside noise.  

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 the above locations usually have tighter tolerances in which only Fiber Mat 25 will fit within. 

 Things to note.

.  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.




.  25mm thick at rest and compressible down to about 4mm

54″ x 36″

.  607 grams per sheet (1.338lbs)

R-Value: 3.99

.  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

.  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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