ResoNix Sound Solutions

Premium Automotive Sound Treatment Solutions

ResoNix Guardian – Automotive Sound Absorbing Pad

ResoNix Guardian is an adhesive-backed Hydrophobic Melamine & Mass Loaded Vinyl composite sound-absorbing, noise-blocking, and thermal-insulating pad for car doors, roofs, walls, and floors, as well as marine engine compartments, engine rooms, and more. Commonly used in car doors for rear-wave absorption to further improve performance and accuracy of door-mounted midbass-speakers.

12″ x 12″ (1 Square Foot) Per Sheet, 1.375″ Thick

6 Sheets Per Box

Peel & Stick Application

Melamine produced in Germany. All other ingredients are produced and assembled in America.


Quantity Discount Type Discount Price Per Item
2-4 Percentage 10 $297.00
5-20 Percentage 15 $280.50

ResoNix Guardian is a Hydrophobic Melamine & MLV Composite Sound Absorber & Noise Barrier with a Polyester Acoustic Facing, and a Peel & Stick Adhesive.


       ResoNix Guardian is comprised of several components, including a Hydrophobic Acoustical Polyester Cloth Facing, a 1″ thick Hydrophobic Melamine foam layer, a 1/8″ thick 1lb Mass Loaded Vinyl Layer, another 1/4″ thick Hydrophobic Melamine foam layer, and a peel-and-stick acrylic-based adhesive backing.

       The product serves three main purposes: absorbing sound, blocking sound, and insulating from heat.

       People commonly use ResoNix Guardian inside car doors for rear wave absorption and diffusion of door-mounted midbass drivers which drastically helps to improve bass and midbass response in car audio systems. Additionally, it is useful on the underside of vehicle roofs to block broadband noise, absorb wind noise, and insulate from heat.

       Furthermore, ResoNix Guardian offers an easy and quick way to treat a camper van for external noise and heat. It is an effective solution to absorb sound, block sound, and insulate from heat, making it a versatile product for various applications.

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

NOTE: This does NOT offer any structural resonance control. Use of ResoNix CLD Squares is still required. ResoNix CLD Squares would be applied first and then ResoNix Guardian on top.


. 12″ x 12″ – 1.375″ thick

. 6 Pieces (6 square feet) per box (Same coverage as a Blackhole Tile Full Box)

. Acrylic Based Peel & Stick Automotive Grade Adhesive Backed

. USA Manufactured

. Full Acoustic Specifications Posted At The Bottom Of The Page

Where Should ResoNix Guardian Be Used?


The most common use and location of ResoNix Guardian would be inside of the door cavity on the outer door skin in sound systems with door-mounted midbass drivers. The use of Guardian here will help improve overall midbass response and lower distortion. The Hydrophobic Melamine layer will absorb sound energy produced by the rear wave of the door-mounted midbass driver, therefor lowering the amount of energy that can cause the outer and inner door skins to resonate, and will also help dissipate the energy faster, resulting in a more accurate impulse response. The Mass Loaded Vinyl Layer will also help. Being a free-floating and limp mass, it will help reflect sound energy away before that energy can reach the door skin. This translates into better, more accurate midbass from your door-mounted midbass drivers. 

Subwoofer Enclosures

Much like doors, the use of ResoNix Guardian will be beneficial to reduce both structural and airborne resonance. While not as important in a subwoofer enclosure since it should be sturdy and non-resonant from the start,  installing ResoNix CLD Squares, then ResoNix Guardian, and then ResoNix Fiber Mat 45 is our recommended go-to for those trying to build the ultimate subwoofer enclosure with no compromises. This will result in an enclosure that has further reduced structural resonance due to the lowered and quicker-absorbed sound energy. Absorbing this energy quicker and more effectively will allow for a much better transient response of the system.


Headliners will also be a common location for ResoNix Guardian since this is the first-ever available noise barrier that will be easily installed and secured in locations that are vertical or upside down fighting against gravity. The Hydrophobic Melamine will take care of sound absoption and do very well at reducing high frequency noise, while the Mass Loaded Vinyl layer will be a broad spectrum noise barrier. But remember, noise barriers need 100% coverage with no flanking paths in order to be effective. This type of installation of Guardian is not for the faint of heart in order to get the most of it. ResoNix Fiber Mat 45 will be a much simpler product to install here. The juice being worth the squeeze is up to you. Note: This product is not very compressible so you must have adequate space to install it above the headliner.

Van Build-Outs

ResoNix Guardian is the ultimate product for your van build. It takes care of all 3 issues that you run into while treating a van; sound absorption, sound blocking, and thermal insulation. The Hydrophobic Melamine is a great thermal insulator and acoustic absorber, while the Mass Loaded Vinyl helps block a much broader spectrum of frequencies, particularly the lower frequency range. Considering ResoNix Guardian is a very simple peel-and-stick product comprised of materials that offer the best performance for their specific intent, there is no better product to treat your van with after ResoNix CLD Squares application. 

Marine Applications

ResoNix Guardian also has a great purpose for marine applications. It is very common for boat owners and manufacturers to look for ways to quiet down the noise and reduce heat transfer from their engine compartments. ResoNix Guardian solvers both of these with a very simple peel-and-stick application to the inside of the engine compartment/cover. Since ResoNix Guardian is fully hydrophobic and has no problem handling extreme temperatures, there is no better option for this application than ResoNix Guardian. For a more budget-friendly approach, ResoNix Fiber Mat 45 is also a great solution but will be more fragile to work around due to its loose and fibrous nature.

Each and every layer of ResoNix Guardian serves its own individual purpose, while also working together towards the common goals of better performance out of your sound system, lowered noise floor inside of the cabin, and less heat transfer to the inside of the vehicle. 

Hydrophobic Melamine Foam

The two layers of Hydrophobic Melamine foam are arguably the most important. Not only is it an excellent acoustic absorber, but it is also an aerospace-grade thermal insulator. This product is quite literally used on the tips of rockets for thermal insulation. Anyways, for car audio applications, Guardian will be used inside of door cavities, stuck to the outer door skin, (AFTER a CLD is applied, preferably ResoNix CLD Squares). In this scenario, the Hydrophobic Melamine is being used to absorb acoustic energy from the rear wave of the door-mounted midbass driver. This will reduce the amount of energy that reaches the outer door skin, which creates the most resonance in the door of a vehicle. This will also in turn reduce the amount of acoustic energy that can be reflected back and transferred into the inner door skin which will cause further resonance but also rattles.

Being used in a headliner/roof will offer some other benefits. With our ResoNix Fiber Mat, you only get acoustic absorption and thermal insulation. With ResoNix Guardian you also get the added benefit of being able to finally install a noise barrier (more on this below) into your roof while still having the benefits of a great acoustic absorber and thermal insulator. As of writing this (January 26th, 2023), we haven’t been able to compare ResoNix Guardian to ResoNix FIber Mat 25 & 45 in a roof installation. The Hydrophobic Melamine will also come in handy for those building out vans for camping and travel purposes. Not only will it drastically lower the noise floor in the vehicle, but it will also help keep heat out in the hot summer months, and help trap heat in during the winter, making your home on wheels more comfortable and efficient. 

But what about water? Isn’t open-cell foam problematic in an automotive environment?

Now, melamine being an open-cell foam would normally be problematic for automotive installations. But for ResoNix Guardian, a proprietary process is used to treat our Melamine to make it fully hydrophobic, inside and out. This isn’t some cheap spray you can buy at Home Depot that will wear off in 4 months. We can guarantee that this product will never absorb water for the life of your vehicle. Due to this, it can be used without worry in door cavities, on the underside of hoods, and even on underbody pans and other places on the outside of the vehicle. No matter what you throw at it, ResoNix Guardian can handle it.

Mass Loaded Vinyl

ResoNix Guardian features a single layer of 1/8″ Mass Loaded Vinyl that has a weight of 1lb. per square foot. This Mass Loaded Vinyl floats between the two layers of Hydrophobic Melamine. Mass Loaded Vinyl is the noise barrier portion of ResoNix Guardian. This will serve two purposes. First, to block outside noise from entering the vehicle, and second, from blocking and reducing the amount of acoustic energy reaching the panel that it is installed onto. For example, let’s say we have ResoNix Guardian installed onto an outer door skin behind a midbass speaker. The rear wave from this midbass speaker would originally fire right into the outer door skin causing a great deal of resonance. 

Now, with ResoNix Guardian in place, most of that acoustic energy that makes it through the Hydrophobic Melamine layer will be blocked by and reflect off of the limp, non-resonant layer of Mass Loaded Vinyl, therefore lowering the amount of energy that is transferred to the highly resonant outer door skin. This logic can be applied anywhere else in a car audio installation. Subwoofer enclosures, midbass enclosures, etc. 

For uses elsewhere, such as roofs or belly pans, the Mass Loaded Vinyl will act as any noise barrier does, and help block any noise trying to make its way into the cabin. Finally, the automotive market has a way to install a noise barrier into roofs and other unconventional areas due to the nature of ResoNix Guardian being able to handle any and all automotive environments and being installed using an extremely resilient yet easy to use peel-and-stick acrylic-based adhesive. 

Non-Woven Polyester Acoustic Fabric Facing

A mouthful, I know. But what this is, while the first time we have seen it used in aftermarket automotive sound treatment products, is pretty self-explanatory. This top layer of ResoNix Guardian is a polyester fabric that is oil and water resistant, and helps achieve two different goals. First, it provides protection and some strength for the Hydrophobic Melamine foam to help protect it from rips and tears, but it also helps tune the acoustic absorption properties of ResoNix Guardian by providing a specific acoustic resistance which helps us target even better low-frequency acoustic absorption which is perfect for when using it in midbass and subwoofer applications, as well as road/engine noise absorption. This fabric facing, just like the Hydrophobic Melamine, is also extremely heat resistant and can be used just about anywhere in or on a vehicle. 

Acrylic-Based Peel-And-Stick Adhesive

As with the rest of our products, the adhesive we have chosen for ResoNix Guardian is the best for the application. It is able to work with and adhere to Hydrophobic Melamine while also being able to stick to pretty much any clean surface and can handle an extremely wide range of temperatures. This allows for an easy installation of ResoNix Guardian without having to worry about long term reliability.

What Does This Combination Of Materials Leave Us With?

Since the materials that ResoNix Guardian is comprised of are fully hydrophobic, each panel can be cut into custom shapes and sizes to fit your individual application needs. The peel-and-stick adhesive makes for an extremely easy installation and finally allows for the installation of a noise barrier inside of door cavities and roofs without needing to figure out a complex mechanical mounting solution, or sacrificing full coverage which finally allows you to have an effective noise barrier, acoustic absorber, and thermal insulator installed anywhere in your vehicle, inside and out. This truly is our most versatile product to date. If you have any questions on where and how this will benefit your installation, feel free to give us a call or send us an email anytime.

ResoNix Guardian Customer Installation Photos

ResoNix Guardian ASTM C423-90a & ASTM E413-73 Testing

Hydrophobic Melamine Data Sheet

Mass Loaded Vinyl Data Sheet

Acoustical Non-Woven Fleece Facing Data Sheet

Peel & Stick Adhesive Backing Data Sheet

USA Manufactured

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