ResoNix Sound Solutions Sound Deadening Buyers Guide

Performance: 1/5

Difficulty of Installation: 1/5

Overall Value: 2.5/5

Materials

• 10-Pack of ResoNix CLD Squares sound deadening material
• 1 Roll of ResoNix Butyl Rope
• 1 Pair of ResoNix Strips (Only if doing a sound system upgrade)

       Our ResoNix Stage-1 sound deadening door kit is very straightforward and would be what your average layman thinks sound deadening a door involves. So, a door is typically made out of 3 layers. The outer skin, the inner skin, and the door panel. The outer skin and door panel are the most important, so this is what we are going to focus on for the Stage-1 door treatment recommendation. First, I recommend treating the small gap between the outer door skin and the crash bar with butyl rope. This will help provide extra stability to the outer door skin for minim cost and effort.

       Next up, how much sound deadener to use on your door? I recommend utilizing 3.5, maybe 4 square feet of ResoNix CLD Squares on the outer door skin. Once the outer door skin is treated, it is time to seal up the inner door skin access holes. For the Stage-2 recommendation, how much sound deadening to use on the inner skin isn’t really on the table. Our Stage-1 kit doesn’t include the appropriate material to do this (CLD is only okay to seal up holes with if they are smaller and non-service points. Larger access holes are not to be sealed with CLD). You can use ABS, PVC, etc, but this portion is on you if you are only going with our Stage-1 kit. If using a PVC plastic or other semi-rigid material to seal up these holes, it is suggested to apply some ResoNix CLD onto the center of the access hole covers. 

       Next up is the door panel itself. Door panels are typically very flimsy and resonant. That said, this area is LESS important if you are only doing this for regular driving situations, so how much sound deadening to use on your door panel will vary depending on your exact use and goal. When doing a Stage-1 application, only apply CLD to the very large/flat pieces of the door. For sound system installations, this is just as, if not more important than the outer door skin, so plan this out well to get the most out of the limited materials you have. Treat the large flat areas with most priority, but be sure to focus on areas around the speaker, as well as any areas of the panel that are multiple overlapping layers that can rattle/buzz against each other. 

       Before you go over those seams with CLD, treat the gaps with ResoNix Butyl rope to decouple the layers from one another to prevent them from rattling against one another. Remember, larger single pieces are much more effective than multiple small pieces. Do not waste your time/material on pieces that are smaller than say 12 square inches or less when doing a Stage-1 installation.  Once this is complete, you can then apply the ResoNix CCF Strips to the outer perimeter of the speakers if you are doing a sound system upgrade. If you are just doing this for general driving purposes, you can skip this unless you want to improve your stock sound system. 

       Our Stage-1 door treatment will definitely yield a good improvement, but will most likely not be satisfactory for the more die-hard enthusiasts. It is quick and easy to do. Do to being relatively inexpensive, quick, and offering a decent improvement, I’d say it is a relatively okay value. Me personally, I suggest doing our Stage-2 at minimum considering I HIGHLY suggest doing this once, and doing it right. The more you disassemble your car, the more you diminish its integrity.

Performance: 3/5

Difficulty of Installation: 2/5

Overall Value: 5/5

Materials

• 20 ResoNix CLD Squares sound deadening material (optional upgrade: ResoNix Mega CLD Squares)
•  1 Sheet of ResoNix Fiber Mat 0.5″ or 1.0″ sound absorber and decoupler material
• 1 Roll of ResoNix Butyl Rope
• 1 Pair of ResoNix CCF Strips (for sound system installations only)

       Our ResoNix Stage-2 Door Sound Deadening Kit is very straightforward. A door is typically made out of 3 layers. The outer skin, the inner skin, and the door panel. The outer skin and door panel are the most important, so this is what we are mostly going to focus on for the Stage-2 door treatment recommendation. How much sound deadening, acoustic absorbers, and how much should you use for our Stage 2 recommendation?

       First, I recommend treating the small gap between the outer door skin and the crash bar with butyl rope. This will help provide extra stability to the outer door skin for minimal cost and effort. Next up, I recommend at least 50%, but preferably more coverage of CLD on the outer door skin. If you are ONLY applying sound treatment for the sake of quieting down your car, you may start approaching diminishing returns at around 30% coverage, but for a sound system, this “25%-rule” goes out the window due to the excess pressure in the door from the speakers. Remember, larger singular pieces perform better than multiple smaller pieces.

       Once the outer door skin is treated, it is time to seal up the inner door skin access holes. For the Stage-2 recommendation, how much sound deadener to use on the inner skin isn’t really on the table. Our Stage-2 kit doesn’t include the appropriate material to do this (CLD is only okay to seal up holes with if they are smaller and non-service points. Larger access holes are not to be sealed with CLD). You can use ABS, PVC, etc, but this portion is on you if you are only going with our Stage-2 kit. If using a plastic or other rigid material to seal up these holes, it is suggested to apply ResoNix CLD onto the access hole covers. 

       Next up is the door panel itself. Door panels are typically very flimsy and resonant. That said, this area is LESS important if you are only doing this for regular driving situations. In these cases, only apply CLD to the very large/flat pieces of the door, and you will want to more so focus on the outer door skin. For sound system installations, this is just as, if not more important than the outer door skin. Treat the large flat areas with most priority, but be sure to focus on areas around the speaker, as well as any areas of the panel that are multiple overlapping layers that can rattle/buzz against each other.

       Before you go over those seams with CLD, treat the gaps with ResoNix Butyl rope to decouple the layers from one another to prevent them from rattling against one another. Once the CLD application is finished, apply full coverage of ResoNix Fiber Mat to the door panel. Be careful to leave screw holes open and unobstructed.  Once this is complete, you can then apply the ResoNix CCF Strips to the outer perimeter of the speakers if you are doing a sound system upgrade. If you are just doing this for general driving purposes, you can skip this unless you want to improve your stock sound system. 

       Optional Upgrade: Add a box of ResoNix Lockout sound absorbing material, or even its big brother, ResoNix Guardian, and apply this over the ResoNix CLD Squares sound deadening material that you installed onto the outer door skin inside of the door cavity. This will help absorb the rear wave of the door-mounted midbass driver and lower distortion from resonance, as well as absorb outside noise that is entering the vehicle.

Performance: 4/5

Difficulty of Installation: 3/5

Overall Value: 3.5/5

Materials

• 100% coverage of ResoNix Mega CLD Squares sound deadening material. Use original ResoNix CLD Squares in areas where Mega CLD Squares are too difficult to conform.
• 100% coverage of ResoNix Fiber Mat 0.5″ or 1.0″ sound absorbing material and decoupler. Or both, and enough properly fill the space.
• 1 Roll of ResoNix Butyl Rope
• 1 Pair of ResoNix CCF Strips (for sound system installations only)
• 1 Box of ResoNix Guardian door cavity sound absorber and noise barrier composite material
• 1 Box of ResoNix CCF Decoupler 7S, or CCF Decoupler 3S (Optional, see below)

       Our ResoNix Stage-3 Door Sound Deadening Kit is very similar to our Stage-2 suggested kit. The main difference is the addition of more CLD coverage, but also the upgrade from the original ResoNix CLD Squares, up to the ResoNix Mega CLD Squares for better performance on outer door skins, flat sections of door panels, and on block-off plates. The next difference is the addition of ResoNix Guardian applied on top of the CLD that is inside of the door cavity on the outer door skin.

       The Stage-3 suggested sound deadeing kit for doors is very straightforward. A door is typically made out of 3 layers. The outer skin, the inner skin, and the door panel. The outer skin and door panel are the most important, so this is what we are mostly going to focus on for the Stage-3 door treatment recommendation. First, I recommend treating the small gap between the outer door skin and the crash bar with butyl rope. This will help provide extra stability to the outer door skin for minim cost and effort.

       Next up for the Stage-3 suggested kit, 80% or more coverage of ResoNix Mega CLD Squares on the outer door skin. Remember, larger pieces perform better than multiple smaller pieces. Next up, installing the ResoNix Guardian on top of the CLD on the outer skin. Use 3 square feet, or up to 100% coverage per door. More coverage is better, and focus on the area directly behind the speaker first and work your way out.

       Once the outer door skin is treated, it is time to seal up the inner door skin access holes. Our Stage-3 kit doesn’t include the appropriate material to do the actual sealing of the access holes. CLD is only okay to seal up holes with if they are smaller and non-service points. Larger access holes are not to be sealed with CLD. You can use ABS, PVC, etc, but this portion is on you if you are only going with our Stage-3 suggested kit. If using a plastic or other rigid material to seal up these holes, it is suggested to apply ResoNix CLD onto the access hole covers. How much sound deadening to use on the access hole block-off plates depends on how resonant they are. I typically just do 100% coverage.

       For our Stage-3 suggested kit, go for full coverage, and spot treat any areas you may deem important on the inner door skin. No need for 100% coverage with this suggested kit on the inner door skin. It is also important to use a gasketing material on your block-off plates (and speaker baffles if applicable) as this will help fully seal off the block-off plates. I would suggest using ResoNix CCF Decoupler 7 or CCF Decoupler 3F or 3S for this the block-off plate and speaker baffle sealing to the inner door skin. If you have other places to use CCF7, that’s what I would suggest. I personally use CCF Decoupler 7 for block off plates and backside of speaker baffles where they meet the inner door skin, and CCF3S and/or CCF3F as a speaker mounting gasket.

       Next up is the door panel itself. Door panels are typically very flimsy and resonant. This area is just as, if not more important than the outer door skin. Treat the large flat areas with CLD with most priority, but be sure to also put special focus on areas around the speaker, as well as any areas of the panel that are multiple overlapping layers that can rattle/buzz against each other. On the materials list for the Stage-3 suggested kit, we have 10 ResoNix CLD Squares listed to accompany the 20 ResoNix Mega CLD Squares. This is for installation on the door panel ONLY IF the door panel would be too difficult to install the ResoNix Mega CLD Squares due to stiffness of the aluminum constraining layer.

       Before you go over those seams with CLD, treat the gaps with ResoNix Butyl rope to decouple the layers from one another to prevent them from rattling against one another. For a Stage-3 installation, I typically end up with about 50% coverage on a typical door panel. That said, door panels vary drastically. Some will require and be able to have 100% coverage easily installed. Others will be difficult to do more than 25% due to the construction of the door panel.

       Once this is done, go over all clips and other small areas and treat with ResoNix Butyl Rope to prevent these small pieces from rattling and buzzing. Once the CLD application is finished, apply full coverage of ResoNix Fiber Mat to the door panel. If Fiber Mat 45 fits without too much compression, use it. If it’s too tight of a fit, use Fiber Mat 25. Be careful to leave screw holes open and unobstructed.  Once this is complete, you can then apply the ResoNix CCF Strips to the outer perimeter of the speakers if you are doing a sound system upgrade. If you are just doing this for general driving purposes, you can skip this unless you want to improve your stock sound system.

Performance: 4.5/5

Difficulty of Installation: 3.5/5

Overall Value: 3/5

Materials

• 100% coverage of ResoNix Mega CLD Squares sound deadening material. Use original ResoNix CLD Squares in areas where Mega CLD Squares are too difficult to conform.
• 100% coverage of ResoNix Fiber Mat 0.5″ or 1.0″ sound absorbing material and decoupler. Or both, and enough properly fill the space.
• 1 Roll of ResoNix Butyl Rope
• 1 Pair of ResoNix CCF Strips (for sound system installations only)
• 1 Box of ResoNix Guardian door cavity sound absorber and noise barrier composite material
• 1 Sheet of ResoNix CCF Decoupler 3S decoupling foam
• 1 Sheet of ResoNix CCF Decoupler 3F decoupling foam
• 1 Sheet of ResoNix Barrier noise barrier material

       The ResoNix Stage-4 Door Sound Deadening Kit is pretty much identical to Stage-3, but with a couple of extra easy steps. The main difference is we are suggesting the addition of the ResoNix CCF Decoupler 3S, ResoNix CCF Decoupler 3F, and the ResoNix Barrier. The CCF Decoupler 3S will be used to help even further isolate small parts of a door to prevent rattles and buzzes. This can be used on door handles, door light housings, clips, wire harnesses, and more. The CCF Decoupler 3F will help with gasketing on the speaker baffle, and other areas that need structure while still being decoupled.

       The ResoNix Barrier will be used to create custom block-off plates to seal the inner door skin access holes. In most situations, it is better than using typical 1/8” ABS plastic as it will resonate less since you can give it shape and structure and the material is naturally inert. If you can use 3/8” ABS, PVC, or Acrylic, that in conjunction with CLD will be better, but it is very rare to be able to fit that on the inner door skin of modern car doors without preventing proper installation of the door panel. So, if your door can fit that and you have the tools to make the block off plates properly, use that instead of the ResoNix Barrier, unless you value the time savings that using the ResoNix Barrier will net you. Typically, it takes me about 20 minutes per 2 doors to do block off plates with ResoNix Barrier. With thicker plastic, it takes about 2 hours for the two doors for various reasons such as needing to make the shape perfect for fitment, applying more material, creating a seal, drilling holes, etc.

       If you have an inner door skin with a 3-dimensional shape to it, it becomes even more difficult to do with plastic since you have to heat mold it. This is where ResoNix Barrier REALLY comes in handy. With ResoNix Barrier, all you have to do is trace out the shape, cut it out with heavy duty scissors, drill your holes, use riv-nuts if that’s your style (I personally do) and install it. Shape and trim the material if need be.

       Also, I suggest going full coverage Of ResoNix Mega CLD Squares on the outer door skin, and as much coverage as possible with whatever version of CLD Squares you can get away with on the door panel. Another tip, at this level you should be really trying to fill out the inside of your door panel with as much ResoNix Fiber Mat as possible. Having pockets of air is performance left on the table.

Performance: 5/5

Difficulty of Installation: 4/5

Overall Value: 2.5/5

Materials

• 100% coverage of ResoNix Mega CLD Squares sound deadening material. Use original ResoNix CLD Squares in areas where Mega CLD Squares are too difficult to conform.
• 100% coverage of ResoNix Fiber Mat 0.5″ or 1.0″ sound absorbing material and decoupler. Or both, and enough properly fill the space.
• 1 Roll of ResoNix Butyl Rope
• 1 Pair of ResoNix CCF Strips (for sound system installations only)
• 100% coverage of ResoNix Guardian door cavity sound absorber and noise barrier composite material
• 1 Sheet of ResoNix CCF Decoupler 3S decoupling foam
• 1 Sheet of ResoNix CCF Decoupler 3F decoupling foam
• 100% coverage plus enough to seal the inner door skin access panels using ResoNix Barrier noise barrier material

       The suggested Stage-5 kit is pretty much identical to Stage-4, but has 2 extra steps. First, full coverage of ResoNix CLD Squares on the inner door skin. If you can get away with just using ResoNix Mega CLD Squares, even better (if you can, you will probably need more than 20 square feet of ResoNix Mega CLD Squares depending on the cars inner door skin design)..

       Also, we will be not only covering the access holes with ResoNix Barrier, but we will also be doing another complete layer of ResoNix Barrier over the entire inner door skin in order to further block outside noise.

       To recap where we are at, the outer door skin, inner door skin, and door panel should all be getting as much coverage as possible using the best version of ResoNix CLD Squares applicable. From there, full coverage of ResoNix Guardian on the outer skin, and full coverage of ResoNix Fiber Mat on the door panel is required. From there, sealing all access holes with ResoNix Barrier, and covering the entire inner door skin after that with another layer of ResoNix Barrier. Let’s also not forget all of the spot treatment along the way using ResoNix Butyl Rope, CCF Decoupler 3S, CCF Decoupler CF, and even the OEM Interior tape if your installation has a need for it.

Stage-1

Performance: 2.5/5 without sunroof, 1.5/5 with sunroof

Difficulty of Installation: 2/5

Overall Value: 3.5/5 without sunroof, 2/5 with sunroof

Materials

• 10-Pack of ResoNix CLD Squares sound deadening material (Optional Upgrade: Replace with ResoNix Mega Pro CLD Squares sound deadening material)
• 1 Roll of ResoNix Butyl Rope

       Our ResoNix Stage-1 sound deadening kit for roofs is also very straightforward and would be what your average layman thinks sound deadening a roof would involve. Roofs are typically much more straight forward than doors as you only need to worry about the roof skin and its support beams as opposed to 3 or more layers like a door. The Stage-1 recommended kit will achieve two things. First, it will help improve transient response from low frequencies being produced from your sound system, and it will also help reduce resonance from driving. It’ll also drastically lessen the intensity from rain impacting your roof. All of these differences will be very obvious in most vehicles. As mentioned, it’ll be more drastic in cars without sunroofs, but still noticeable in cars that feature a window overhead.

       First step is to drop the headliner. Most vehicles only require you to remove the A/B/C Pillars, grab handles, sun visors, overhead lights, and any overhead consoles in order to do this. Once it is dropped, you should be able to complete your work without even needing to completely remove the headliner from the interior, which can get tricky in some vehicles without creasing it.

       Once the headliner is dropped, use the ResoNix Butyl Rope to help bridge the gap between parts of the roof skins support beams and the roof skin itself. This will help stabilize the roof skin. Up next, apply ResoNix CLD Squares. When not doing full coverage, it is important to space pieces out evenly, starting application from the center of the resonant panel, in this case, the roof skin. Remember, larger pieces are much more effective than multiple smaller pieces.

Tip: Put the edge of the CLD just a hair over the roof support beams. This will further utilize the supports to help stabilize the roof skin. Do not fully cover them. Just overlapping by 3/4″ is fine.

Optional Upgrade: Use ResoNix Mega CLD Squares sound deadening material instead of the original CLD Squares to get even better resonance control performance on the roof.

Performance: 3/5 without sunroof, 2/5 with sunroof

Difficulty of Installation: 2.5/5

Overall Value: 4/5 without sunroof, 2.5/5 with sunroof

Materials

• 10-pack of ResoNix CLD Squares sound deadening material (Optional Upgrade: Replace with ResoNix Mega CLD Squares).
• 1 Roll of ResoNix Butyl Rope
• 100% coverage of ResoNix Fiber Mat Black Edition 1/0 or 0.5″ (I’d wager 85% of vehicles can get away with 1.0″ in the roof).

       Our ResoNix Stage-2 sound deadening kit for roofs only changes one thing from the Stage-1 for a roof installation, which is the addition of ResoNix Fiber Mat. The addition of ResoNix Fiber Mat takes this install to the next level since it introduces sound absorption (and even thermal insulation) into the mix, AND can even provide further stability for the roof skin. Wind noise generated overhead is typically over 250Hz. ResoNix Fiber Mat does an excellent job at absorbing these frequencies, so a large majority of noise that you hear from overhead will be absorbed before it even reaches you. For sound absorption purposes, you want the thickest material possible without compressing it too much, or ideally not compressing it at all. If you can fit Fiber Mat 45 without compressing it more than 30%, go for it. In my experience, almost all headliners can be installed very easily with Fiber Mat 45 installed.

       How much sound deadening and sound absorber should you use if you have a sunroof? Well, if you have a car with a sunroof, especially one that is large relative to the size of the roof, just do your best. Get the most coverage you can without impeding the function of the sunroof and its parts.

Performance: 3.5/5 without sunroof, 2/5 with sunroof

Difficulty of Installation: 2.5/5

Overall Value: 4.5/5 without sunroof, 2.5/5 with sunroof

Materials

• 80%+ coverage of ResoNix CLD Squares sound deadening material (Optional Upgrade: Replace with ResoNix Mega CLD Squares sound deadening material).
• . 1 Roll of ResoNix Butyl Rope
• 100% coverage of ResoNix Fiber Mat Black Edition 1/0 or 0.5″ (I’d wager 85% of vehicles can get away with 1.0″ in the roof).

       Our ResoNix Stage-3 sound deadening kit for roofs only changes one thing from Stage-2 for a roof installation. The application of more CLD Squares to target 80% or more coverage is the only difference. The additional CLD Squares will help further reduce resonance of the roof skin. The higher coverage is going to be especially beneficial in sound system installations where the “25% coverage rule” goes out the window since there are outside forces acting on the panels instead of just typical mechanical energy transfer from normal driving.

       The addition of ResoNix Fiber Mat takes this install to the next level since it introduces sound absorption (and even thermal insulation) into the mix, AND can even provide further stability for the roof skin. Wind noise generated overhead is typically over 250Hz. ResoNix Fiber Mat does an excellent job at absorbing these frequencies, so a large majority of noise that you hear from overhead will be absorbed before it even reaches you. For sound absorption purposes, you want the thickest material possible without compressing it too much, or ideally not compressing it at all. If you can fit Fiber Mat 45 without compressing it more than 30%, go for it. In my experience, almost all headliners can be installed very easily with Fiber Mat 45 installed.

       How much sound deadening and sound absorber should you use if you have a sunroof? If you have a car with a sunroof, especially one that is large relative to the size of the roof, just do your best. Get the most coverage you can without impeding the function of the sunroof and its parts. Stage-3 is as far as I would recommend going. Anything more than that is probably a waste. Thankfully, glass does much better than thin sheet metal at blocking sound and being non-resonant, so you have that going for you.

Performance: 4.5/5 without sunroof, not recommended with sunroof

Difficulty of Installation: 3.5/5 with ResoNix Guardian, 4.5/5 with ResoNix Barrier

Overall Value: 3/5

Materials

• 100% coverage of ResoNix Mega CLD Squares sound deadening material
• 1 Roll of ResoNix Butyl Rope
• 100% coverage of ResoNix Fiber Mat 0.5″ or 1.0″ sound absorbing material and decoupler. Or both, and enough properly fill the space.
• 100% coverage of ResoNix Guardian sound absorber and noise barrier composite material, or enough to do 100% coverage. This is only for vehicles that have a lot of space between the headliner and roof skin. ResoNix Guardian isn’t very compressible like Fiber Mat is, and is nearly 1.5 inches thick. This will not be often that you can fit this, but if you can with the addition of Fiber Mat, great. If you cannot, replace ResoNix Guardian with ResoNix Barrier of full coverage. This will yield a similar result, but will be more difficult to install since it does not install via a peel & stick adhesive.

       Our ResoNix Stage-4 kit for sound deadening roofs would be the same as Stage-3, but with the addition of preferably ResoNix Guardian, but if that cannot fit, ResoNix Barrier. ResoNix Guardian introduces not only further sound absorption capabilities, but also introduces the use of a noise barrier which will help with reducing no only the frequencies higher than 250Hz, but low frequencies as well. Technically, the ResoNix Barrier may be a higher performing option here since it has a heavier noise barrier layer, but it would be much more difficult to install, as it would need to be mechanically secured as opposed to peel and stick like ResoNix Guardian is.

       For the installation of Guardian, stick it to the CLD after its installation, and stick the Fiber Mat to the top of the Guardian for a relatively easy installation. If doing Barrier instead of Guardian, mechanically affix the ResoNix Barrier to the roof after the CLD installation, and install the Fiber Mat directly to the back side of the headliner.  

Performance: 5/5 without sunroof, not recommended with sunroof

Difficulty of Installation: 5/5

Overall Value: 2.5/5

Materials

• 100% coverage of ResoNix Mega CLD Squares sound deadening material
• 1 Roll of ResoNix Butyl Rope
• 100% coverage of ResoNix Fiber Mat 0.5″ or 1.0″ sound absorbing material and decoupler. Or both, and enough properly fill the space.
• 100% coverage of ResoNix Guardian sound absorber and noise barrier composite material
• 100% coverage of ResoNix Barrier

       The ResoNix Stage-5 roof sound deadening kit is pretty simple in concept. 100% coverage of all of our major products. The Stage-5 recommended kit is VERY rarely going to be applicable, but in the situation that you can fit up to 2.5” or more of sound treatment material and you want to go balls to the wall, this is for you. First start off with the butyl rope between the supports and the roof skin, then do 100% coverage of ResoNix Mega CLD Squares on the roof skin. From there, 100% coverage of ResoNix Guardian stuck directly to the CLD. From there, you will need to mechanically affix ResoNix Barrier on top of the ResoNix Guardian. How you do this will depend on the vehicle.

       From there, do 100% coverage of ResoNix Fiber Mat. I would apply this right to the headliner itself in this situation so you do not impede the serviceability of the ResoNix Barrier layer. To take it a step further, you can do another layer of Fiber Mat in between the layer of Guardian and Barrier. This will essentially float ResoNix Barrier and be perfectly decoupled if done correctly, yielding the best performance out of a noise barrier possible, with the added benefit of even further sound absorption.

Performance: 1.5/5

Difficulty of Installation: 1/5

Overall Value: 2/5

Materials

• Approximately 50% coverage of ResoNix CLD Squares on the rear deck metal and the back of the plastic trim panels
• Approximately 50% coverage of ResoNix CLD Squares on the metal structure behind the C-pillar trim panels
• Use ResoNix Butyl Rope and/or ResoNix CCF Decoupler 3S Tape to treat any smaller trim panels attached to the rear deck and C-pillars to prevent buzzes and rattles
• Optional Upgrade: Replace ResoNix CLD Squares with ResoNix Mega CLD Squares for enhanced performance
• Note: If speakers are installed in the rear deck, use ResoNix CCF Strips around the speakers to seal/couple the speaker to the grille/trim panel

       Our Stage-1 recommendation for the rear deck and C-pillars focuses on addressing the most critical areas prone to vibration and noise. Begin by removing the rear deck plastic trim panel and the C-pillar trim panels to expose the underlying metal surfaces.

Rear Deck Metal:

• Apply approximately 50% coverage of ResoNix CLD Squares to the metal surface of the rear deck. Focus on large, flat areas that are more likely to resonate.
• This application will help dampen vibrations and reduce noise from the rear speakers or external sources.

Rear Deck Plastic Trim Panel:

• Apply ResoNix CLD Squares to about 50% of the backside of the plastic trim panel. Concentrate on flat sections and areas near speaker mounts or attachment points to reduce panel resonance.

C-Pillar Metal Structure:

• Apply approximately 50% coverage of ResoNix CLD Squares to the metal structure behind the C-pillar trim panels. This helps reduce vibrations that can travel through the vehicle’s frame.

C-Pillar Trim Panels:

• Treat the backside of the C-pillar plastic trim panels with ResoNix CLD Squares, focusing on areas that are prone to vibration.

Smaller Trim Panels and Attachments:

• Use ResoNix Butyl Rope and/or ResoNix CCF Decoupler 3S Tape to address smaller trim pieces, clips, and attachment points. This will prevent buzzes and rattles caused by loose or vibrating components.

Optional Upgrade:

• Upgrading to ResoNix Mega CLD Squares provides enhanced damping performance, which is particularly beneficial for high-vibration environments (subwoofers in the trunk, and/or speakers installed in the rear deck) or for achieving the best possible results.
• Note: If speakers are installed in the rear deck, use ResoNix CCF Strips around the speakers to seal/couple the speaker to the grille/trim panel.

Performance: 3/5

Difficulty of Installation: 1.5/5

Overall Value: 5/5

Materials

• Upgrade CLD coverage to approximately 75–100% using ResoNix CLD Squares on all metal surfaces and trim panels that are listed in Stage-1
• Add 100% coverage of ResoNix Fiber Mat to the underside of the rear deck plastic trim panel and C-pillar trim panels
• Continue using ResoNix Butyl Rope and ResoNix CCF Decoupler 3S Tape for smaller trim pieces
• Optional Upgrade: Replace ResoNix CLD Squares with ResoNix Mega CLD Squares for enhanced performance
• Note: If speakers are installed in the rear deck, use ResoNix CCF Strips around the speakers to seal/couple the speaker to the grille/trim panel

       In Stage-2, we build upon the initial treatment by increasing the coverage of vibration-damping materials and adding sound-absorbing layers.

Increased CLD Coverage:

• Apply 75–100% coverage of ResoNix CLD Squares on the rear deck metal, rear deck plastic trim panel, C-pillar metal structure, and C-pillar trim panels.
• Full coverage ensures maximum vibration damping, reducing the potential for resonant frequencies and structural noise.

Addition of ResoNix Fiber Mat:

• Apply 100% coverage of ResoNix Fiber Mat to the underside of the rear deck plastic trim panel and C-pillar trim panels.
• ResoNix Fiber Mat acts as an excellent sound absorber, reducing airborne noise and preventing reflections within the cabin. It also acts as a decoupler and helps prevent the panels from rattling/buzzing against other hard surfaces it may otherwise come into contact with.
• Ensure that ResoNix Fiber Mat is securely adhered to the panels and does not obstruct any mounting points or interfere with reinstallation.

Smaller Trim Panels and Attachments:

• Continue to use ResoNix Butyl Rope and ResoNix CCF Decoupler 3S Tape to treat smaller components, ensuring all potential sources of noise are addressed.

Optional Upgrade:

• Upgrading to ResoNix Mega CLD Squares provides enhanced damping performance, which is particularly beneficial for high-vibration environments (subwoofers in the trunk, and/or speakers installed in the rear deck) or for achieving the best possible results.
• Note: If speakers are installed in the rear deck, use ResoNix CCF Strips around the speakers to seal/couple the speaker to the grille/trim panel.

Performance: 4/5

Difficulty of Installation: 2/5

Overall Value: 3/5

Materials

• 100% coverage of ResoNix Mega CLD Squares on all metal surfaces and trim panels
• Add 100% coverage of ResoNix Fiber Mat to the underside of the rear deck and C-pillar trim panels
• Add 100% coverage of ResoNix Barrier to the metal surfaces
• Continue using ResoNix Butyl Rope and/or ResoNix CCF Decoupler 3S Tape for smaller trim pieces
• Note: If speakers are installed in the rear deck, use ResoNix CCF Strips around the speakers to seal/couple the speaker to the grille/trim panel
• Optional Upgrade: Add ResoNix Fiber Mat in between the CLD and the Barrier layers on the top (interior-side) of the rear deck.

       Stage-3 elevates sound deadening by utilizing the most effective materials and adding a noise barrier layer.

Full Coverage with Mega CLD Squares:

• Metal Surfaces and Trim Panels: Apply 100% coverage of ResoNix Mega CLD Squares to all metal surfaces (rear deck and C-pillars) and the backside of all plastic trim panels. The increased rigidity of the thicker constraining layer that is featured on ResoNix Mega CLD Squares more effectively eliminates resonance.

Addition of ResoNix Fiber Mat:

• Trim Panels: Continue to apply 100% coverage of ResoNix Fiber Mat to the underside of the rear deck and C-pillar trim panels. This further enhances sound absorption within the cabin, and decouples the panels to prevent panel-on-panel vibration and buzzes.

Addition of ResoNix Barrier:

• Metal Surfaces: Apply 100% coverage of ResoNix Barrier over the Mega CLD Squares on the metal surfaces of the rear deck and C-pillars. This moldable noise barrier effectively blocks sound transmission, further isolating the cabin from external noise sources. An optional upgrade here would be to add a layer of ResoNix Fiber Mat in between the CLD and the Barrier layers for further sound absorption, better decoupling of the ResoNix Barrier, and a larger and better air gap for the ResoNix Barrier which allows it to be more effective.

Smaller Trim Panels and Attachments:

• Use ResoNix Butyl Rope and/or ResoNix CCF Decoupler 3S Tape to address any remaining smaller components.

Note: If speakers are installed in the rear deck, use ResoNix CCF Strips around the speakers to ensure optimal performance and prevent vibrations and rattles.

Performance: 4.5/5
Difficulty of Installation: 3.5/5
Overall Value: 2/5

Materials

• 100% coverage of ResoNix Mega CLD Squares on the interior side of the rear deck metal
• 100% coverage of ResoNix Guardian on top of the CLD on the interior side of the rear deck
• 100% coverage of ResoNix Mega CLD Squares and ResoNix Fiber Mat on the bottom (trunk-side) of the rear deck metal
• Rear Deck Trim Panel: 100% coverage of ResoNix Mega CLD Squares and ResoNix Fiber Mat on its underside
• Use ResoNix Butyl Rope and/or ResoNix CCF Decoupler 3S Tape for smaller built-in trims and inserts
• Optional Upgrade: Add 100% coverage of ResoNix Barrier over the ResoNix Guardian
• C-Pillars: 100% coverage of ResoNix Mega CLD Squares topped with ResoNix Fiber Mat on the trim panels; treat the metal underneath with ResoNix Mega CLD Squares and ResoNix Barrier
• Note: If speakers are installed in the rear deck, use ResoNix CCF Strips around the speakers to seal and couple them to the grille/trim panel

       In Stage-4, we advance our sound deadening efforts by introducing ResoNix Guardian and enhancing treatments on both sides of the rear deck metal. This stage is likely to be difficult to fit in standard vehicles and is most suitable for custom installations where interior trim panels are built over the sound treatment materials.

Interior Side of Rear Deck Metal:

       Apply 100% coverage of ResoNix Mega CLD Squares, then add 100% coverage of ResoNix Guardian on top of the CLD to provide exceptional sound absorption and thermal insulation.

Bottom (Trunk-Side) of Rear Deck Metal:

       Apply 100% coverage of ResoNix Mega CLD Squares followed by 100% coverage of ResoNix Fiber Mat to absorb sound within the trunk area.

Rear Deck Trim Panel:

       Treat the underside with 100% coverage of ResoNix Mega CLD Squares and top it with ResoNix Fiber Mat. Use ResoNix Butyl Rope and/or ResoNix CCF Decoupler 3S Tape to address smaller built-in trims and inserts, preventing rattles and buzzes.

C-Pillars:

       Apply 100% coverage of ResoNix Mega CLD Squares topped with ResoNix Fiber Mat on the trim panels. Treat the metal underneath with ResoNix Mega CLD Squares and add ResoNix Barrier if possible to block sound transmission.

Optional Upgrade:

       For maximum noise blocking, add 100% coverage of ResoNix Barrier over the ResoNix Guardian on the interior side of the rear deck metal. Be mindful of the added thickness and potential fitment issues.

Note:

If speakers are installed in the rear deck, use ResoNix CCF Strips around the speakers to ensure optimal audio performance and prevent vibrations.

Considerations for Stage-4 and Stage-5:

• Fitment Challenges: The substantial increase in material layers may cause fitment issues. These stages are most suitable for custom installations where adjustments can be made to accommodate the added thickness.
• Professional Installation Recommended: Due to complexity and potential fitment challenges, professional installation is advisable to ensure proper fit and function.

Performance: 5/5
Difficulty of Installation: 5/5
Overall Value: 2/5

Materials

• 100% coverage of ResoNix Mega CLD Squares on the interior side of the rear deck metal
• 100% coverage of ResoNix Guardian on top of the CLD, topped with 100% coverage of ResoNix Barrier on the interior side of the rear deck metal
• Rear Deck Trim Panel: Apply two layers of ResoNix Mega CLD Squares, topped with ResoNix Fiber Mat on its underside
• Bottom (Trunk-Side) of Rear Deck Metal: Replace ResoNix Fiber Mat with ResoNix Guardian, topped with ResoNix Barrier
• Use ResoNix Butyl Rope and/or ResoNix CCF Decoupler 3S Tape for smaller built-in trims and inserts
• C-Pillars: Same as Stage-4; 100% coverage of ResoNix Mega CLD Squares topped with ResoNix Fiber Mat on the trim panels; treat the metal underneath with ResoNix Mega CLD Squares and ResoNix Barrier
• Note: If speakers are installed in the rear deck, use ResoNix CCF Strips around the speakers

       Stage-5 represents the highest level you can take sound deadening for the rear deck and C-pillars, offering maximum noise reduction and vibration control. This stage is ideal for those seeking the highest level of acoustic performance and are willing to undertake a complex installation.

Interior Side of Rear Deck Metal:

       Apply 100% coverage of ResoNix Mega CLD Squares, then add 100% coverage of ResoNix Guardian on top of the CLD, and finish with 100% coverage of ResoNix Barrier over the Guardian to maximize noise blocking.

Rear Deck Trim Panel:

       Apply two layers of ResoNix Mega CLD Squares to the underside, topped with ResoNix Fiber Mat. Ensure that the added thickness does not interfere with reinstallation.

Bottom (Trunk-Side) of Rear Deck Metal:

       Replace ResoNix Fiber Mat with ResoNix Guardian over 100% coverage of ResoNix Mega CLD Squares, then top with ResoNix Barrier to block sound transmission from the trunk area.

C-Pillars:

       Treat as in Stage-4. Apply 100% coverage of ResoNix Mega CLD Squares topped with ResoNix Fiber Mat on the trim panels, and treat the metal underneath with ResoNix Mega CLD Squares and ResoNix Barrier.

Smaller Trim Panels and Attachments:

       Use ResoNix Butyl Rope and/or ResoNix CCF Decoupler 3S Tape to eliminate any potential noise sources from smaller trims and inserts.

Note:

If speakers are installed in the rear deck, use ResoNix CCF Strips around the speakers to ensure optimal audio performance and prevent vibrations.

Considerations for Stage-4 and Stage-5:

• Fitment Challenges: The substantial increase in material layers may cause fitment issues. These stages are most suitable for custom installations where adjustments can be made to accommodate the added thickness.
• Professional Installation Recommended: Due to complexity and potential fitment challenges, professional installation is advisable to ensure proper fit and function.

Performance: 2.5/5
Difficulty of Installation: 1/5
Overall Value: 3/5

Materials

• Approximately 50% coverage of ResoNix CLD Squares
• Spot treatment with ResoNix Butyl Rope and/or ResoNix CCF Decoupler 3S Tape for smaller inserts and trim panels
• Optional Upgrade: Replace ResoNix CLD Squares with ResoNix Mega CLD Squares for enhanced performance

Our Stage-1 recommendation focuses on addressing the most critical areas prone to vibrations and rattles. Begin by removing the B-pillar and other relevant trim panels to expose the underlying metal surfaces.

• Apply ResoNix CLD Squares: Cover approximately 50% of the metal surfaces with ResoNix CLD Squares, concentrating on large, flat areas to reduce resonance.
• Spot Treat Inserts and Trim Panels: Use ResoNix Butyl Rope and/or ResoNix CCF Decoupler 3S Tape to treat smaller inserts or trim panels attached to the main panel. This prevents buzzes and rattles caused by loose or vibrating components.

Optional Upgrade:

• Upgrade to ResoNix Mega CLD Squares: For improved vibration damping, replace ResoNix CLD Squares with ResoNix Mega CLD Squares, which offer greater mass and rigidity.

Performance: 3.5/5
Difficulty of Installation: 1.5/5
Overall Value: 4/5

Materials

• Approximately 75% coverage of ResoNix CLD Squares
• Spot treatment with ResoNix Butyl Rope and/or ResoNix CCF Decoupler 3S Tape
• 100% coverage of ResoNix Fiber Mat on the back of the panel over the CLD
• Optional Upgrade: Swap ResoNix CLD Squares for ResoNix Mega CLD Squares

In Stage-2, we build upon the previous stage by increasing the coverage of vibration-damping materials and adding a sound-absorbing layer.

• Increase CLD Coverage: Apply approximately 75% coverage of ResoNix CLD Squares to the metal surfaces, focusing on areas prone to vibration.
• Spot Treat Inserts and Trim Panels: Continue using ResoNix Butyl Rope and/or ResoNix CCF Decoupler 3S Tape to secure smaller components and prevent rattles.
• Add ResoNix Fiber Mat: Apply 100% coverage of ResoNix Fiber Mat over the CLD on the back of the trim panels. This enhances sound absorption and reduces airborne noise.

Optional Upgrade:

• Upgrade to ResoNix Mega CLD Squares: For superior damping, replace ResoNix CLD Squares with ResoNix Mega CLD Squares.

Performance: 3.5/5
Difficulty of Installation: 3/5
Overall Value: 3.5/5

Materials

• 100% coverage of ResoNix Mega CLD Squares
• Spot treatment with ResoNix Butyl Rope and/or ResoNix CCF Decoupler 3S Tape
• 100% coverage of ResoNix Fiber Mat on top of the Mega CLD Squares

In Stage-3, we aim for maximum vibration damping and sound absorption.

• Full CLD Coverage: Apply 100% coverage of ResoNix Mega CLD Squares to all metal surfaces and the back of the trim panels.
• Spot Treat Inserts and Trim Panels: Continue to address smaller components with ResoNix Butyl Rope and/or ResoNix CCF Decoupler 3S Tape.
• Full Coverage of Fiber Mat: Apply 100% coverage of ResoNix Fiber Mat over the Mega CLD Squares to enhance sound absorption.

Performance: 4.5/5
Difficulty of Installation: 2.5/5
Overall Value: 2.5/5

Materials

• 100% coverage of ResoNix Mega CLD Squares
• Spot treatment with ResoNix Butyl Rope and/or ResoNix CCF Decoupler 3S Tape
• 100% coverage of ResoNix Fiber Mat on top of the Mega CLD Squares
• Add 100% coverage of ResoNix Barrier over the metal behind the trim panel

In Stage-4, we introduce a noise barrier layer to block sound transmission.

• Full CLD Coverage: Apply 100% coverage of ResoNix Mega CLD Squares to the metal surfaces.
• Spot Treat Inserts and Trim Panels: Continue using ResoNix Butyl Rope and/or ResoNix CCF Decoupler 3S Tape.
• Full Coverage of Fiber Mat: Apply ResoNix Fiber Mat over the Mega CLD Squares.
• Add ResoNix Barrier: Install 100% coverage of ResoNix Barrier over the metal behind the trim panel to block residual noise.

Performance: 5/5
Difficulty of Installation: 5/5
Overall Value: 2/5

Materials

• 100% coverage of ResoNix Mega CLD Squares
• Spot treatment with ResoNix Butyl Rope and/or ResoNix CCF Decoupler 3S Tape
• 100% coverage of ResoNix Fiber Mat on top of the Mega CLD Squares
• Add 100% coverage of ResoNix Guardian over the metal behind the trim panel
• Cover ResoNix Guardian with 100% coverage of ResoNix Barrier

Note: Adding ResoNix Guardian is applicable only for trim panels that have plenty of space behind them.

In Stage-5, we achieve the highest level of sound deadening by adding an additional sound-absorbing layer.

• Full CLD Coverage: Apply 100% coverage of ResoNix Mega CLD Squares.
• Spot Treat Inserts and Trim Panels: Continue using ResoNix Butyl Rope and/or ResoNix CCF Decoupler 3S Tape.
• Full Coverage of Fiber Mat: Apply ResoNix Fiber Mat over the Mega CLD Squares.
• Add ResoNix Guardian: Install 100% coverage of ResoNix Guardian over the metal behind the trim panel.
• Cover with ResoNix Barrier: Apply 100% coverage of ResoNix Barrier over the ResoNix Guardian to maximize noise blocking.

Performance: 0.5/5 for modern vehicles, 2.5/5 for vintage vehicles

Difficulty of Installation: 1/5 once access is gained to the firewall. Gaining access to the firewall will vary drastically in difficulty from vehicle to vehicle.

Overall Value: 0.5/5 for most modern vehicles. 2/5 for most vintage vehicles.

Materials

• 50% coverage of ResoNix CLD Squares on the interior side of the firewall (engine side optional)
• 50% coverage of ResoNix CLD Squares on the underside of the hood, applied beneath the OEM hood liner. (If there is no OEM hood liner material, it is highly recommended to add ResoNix Fiber Mat Silver on top to help with sound absorption and thermal insulation.)
• Optional Upgrade: Replace ResoNix CLD Squares with ResoNix Mega CLD Squares for enhanced performance

       Our Stage-1 recommendation for firewall and hood treatment focuses on the basics to provide a noticeable improvement in noise reduction and thermal insulation with minimal effort and cost. Please note, the Stage-1 suggestions for the Hood & Firewall are not very effective to where I personally would find it worth it for a modern vehicle. For vintage vehicles, this is a different story since they have hoods and firewalls that are not nearly as structural and insulating, and a Stage-1 installation can still yield noticeable results.

       Starting with the interior side of the firewall, apply ResoNix CLD Squares to cover approximately 50% of the surface area. Focus on large, flat sections for maximum effectiveness. If you’re up for an extra step, you can also treat the engine side of the firewall, although this is optional at this stage.

       For the underside of the hood, remove the OEM hood liner carefully to expose the metal surface. Apply ResoNix CLD Squares to cover about 50% of the area, again concentrating on the larger, flatter sections. Once installed, replace the OEM hood liner. This application will help dampen resonance and help reduce some engine noise transmitted through the hood.

       The optional upgrade to ResoNix Mega CLD Squares offers superior damping performance due to its thicker constraining layer and higher mass. If you desire greater noise reduction and are willing to invest a bit more, this upgrade is worthwhile.

Performance: 2.5/5 for modern vehicles, 3.5/5 for vintage vehicles.

Difficulty of Installation: 2/5 once you have access to the firewall.

Overall Value: 3/5 for modern vehicles, 4/5 for vintage vehicles.

Materials

• 50% coverage of ResoNix CLD Squares on the interior side of the firewall
• 100% coverage of ResoNix Fiber Mat on the interior side of the firewall
• (Ideal for vintage vehicles, will be difficult for modern vehicles) 50–100% coverage of ResoNix CLD Squares on the engine side of the firewall
• (Ideal for vintage vehicles, will be difficult for modern vehicles) 100% coverage of ResoNix Fiber Mat Silver on the engine side of the firewall
• 50–100% coverage of ResoNix CLD Squares on the underside of the hood.
• 100% coverage of ResoNix Fiber Mat Silver on the underside of the hood. If your vehicle came with an OEM Hood Liner, it is not unwise to reinstall it back over the ResoNix materials if possible, but is not 100% necessary. 
• Optional Upgrade: Replace ResoNix CLD Squares with ResoNix Mega CLD Squares for enhanced performance

       Our Stage-2 recommendation builds upon Stage-1 by adding sound-absorbing and thermal-insulating layers to both the firewall and hood. This stage offers noticeable improvements, especially for vintage vehicles with less factory insulation. For modern vehicles, while the benefits may be more subtle, those seeking a quieter and cooler cabin will still appreciate the enhancements. To me, this is where the juice starts becoming worth the squeeze for modern vehicles. (I have had many customers reach out after doing this treatment on modern vehicles and were very happy with the end results).

Firewall (Interior Side):

       Begin by applying 50% coverage of ResoNix CLD Squares to the interior side of the firewall, focusing on large, flat areas prone to vibration. Next, apply a full 100% coverage layer of ResoNix Fiber Mat over the CLD-treated areas. The Fiber Mat serves as an excellent sound absorber and thermal insulator, reducing airborne engine noise and heat transfer into the cabin.

Firewall (Engine Side):

       This will be easier and much more worthwhile on vintage vehicles. Not so worth while on modern vehicles. On the engine side of the firewall, apply 50–100% coverage of ResoNix CLD Squares, depending on accessibility and desired performance. Follow this with a 100% coverage layer of ResoNix Fiber Mat Silver, which is designed to withstand the harsh conditions of the engine bay while providing sound absorption, thermal insulation, and a radiant heat barrier layer. A radiant heat barrier is different and separate from a thermal insulator in that it primarily reflects radiant heat rather than absorbing and slowing down conductive heat transfer, which is the function of a thermal insulator.

Hood:

       Remove the OEM hood liner to expose the underside of the hood. Apply 50–100% coverage of ResoNix CLD Squares, concentrating on larger, flatter sections for maximum effectiveness. Then, install a full 100% coverage layer of ResoNix Fiber Mat Silver. If there is no OEM hood liner, adding the Fiber Mat Silver is highly recommended to enhance sound absorption and thermal insulation. Reinstall the OEM hood liner if present.

Optional Upgrade:

       Upgrading to ResoNix Mega CLD Squares will provide superior damping due to their thicker constraining layer and higher mass, making it a worthwhile investment for those seeking greater noise reduction.

Performance: 3/5 for Modern Vehicles. 4/5 for Vintage Vehicles

Difficulty of Installation: 2.5/5 once you have access to the firewall. 

Overall Value: 3.5/5 for modern vehicles with louder engines. 4/5 for vintage vehicles. 

Materials

• 75–100% coverage of ResoNix Mega CLD Squares on the interior side of the firewall
• 100% coverage of ResoNix Fiber Mat on the interior side of the firewall
• 100% coverage of ResoNix Barrier on the interior side of the firewall
• (Ideal for vintage vehicles, will be difficult for modern vehicles) 75–100% coverage of ResoNix Mega CLD Squares on the engine side of the firewall
• (Ideal for vintage vehicles, will be difficult for modern vehicles) 100% coverage of ResoNix Fiber Mat Silver on the engine side of the firewall
• 75–100% coverage of ResoNix Mega CLD Squares on the underside of the hood
• 100% coverage of ResoNix Fiber Mat Silver on the underside of the hood
• Optional Upgrade: For flat hoods with ample space, add 100% coverage of ResoNix Guardian
• Note: If your vehicle came with an OEM hood liner, you may reinstall it over the ResoNix materials if possible, but it is not strictly necessary

       In Stage-3, we take a more comprehensive approach to sound deadening and thermal insulation, suitable for vehicles requiring extensive treatment—particularly vintage models with minimal factory insulation. For modern vehicles, this stage also offers significant improvements for those seeking optimal cabin comfort.

Firewall (Interior Side):

       Apply 75–100% coverage of ResoNix Mega CLD Squares to the interior side of the firewall for maximum vibration damping. Follow this with a full 100% coverage layer of ResoNix Fiber Mat to absorb sound and insulate against conductive heat transfer. Then, add a 100% coverage layer of ResoNix Barrier to block any remaining noise and thermal transfer into the cabin. In practice, it is best to do CLD, then Fiber Mat, and then Barrier, but if it is easier to do CLD, then Barrier, then Fiber Mat, it wont be the end of the world. 

Firewall (Engine Side):

       This step is optional and more beneficial for vintage vehicles. Modern vehicles often have adequate factory insulation on the engine side, making additional treatment less impactful. If you choose to proceed, apply 75–100% coverage of ResoNix Mega CLD Squares on the engine side of the firewall. Then, install a full 100% coverage layer of ResoNix Fiber Mat Silver. The Fiber Mat Silver not only provides sound absorption and thermal insulation but also acts as a radiant heat barrier, reflecting radiant heat away from the cabin.

Hood:

       This is only for hoods that are very flat and has plenty of working tolerance to add thick materials, as ResoNix Guardian will not be easy to bend, and is very thick. Optional if you need it to be able to contour to bends easier, swap ResoNix Guardian for ResoNix Lockout.

       Remove the OEM hood liner if present to expose the underside of the hood. Apply 75–100% coverage of ResoNix Mega CLD Squares, focusing on large, flat areas for maximum effectiveness. Then, install a full 100% coverage layer of ResoNix Guardian. This material absorbs sound, insulates against heat, and blocks sound, protecting both the hood’s paint and reducing engine heat and sound entering the cabin.

Note: Reinstall the OEM hood liner over the ResoNix materials if possible. While not strictly necessary, it can provide additional protection and insulation.

Performance: 4/5 for Modern Vehicles with louder engines, 4.5/5 for Vintage Vehicles
Difficulty of Installation: 3/5 once you have access to the firewall
Overall Value: 2/5 for modern vehicles, 3/5 for vintage vehicles

Materials

• 75–100% coverage of ResoNix Mega CLD Squares on the interior side of the firewall
• 100% coverage of ResoNix Fiber Mat on the interior side of the firewall
• 100% coverage of ResoNix Barrier on the interior side of the firewall
• (Ideal for vintage vehicles; will be difficult for modern vehicles) 75–100% coverage of ResoNix Mega CLD Squares on the engine side of the firewall
• (Ideal for vintage vehicles; will be difficult for modern vehicles) 100% coverage of ResoNix Guardian on the engine side of the firewall. If there are curves and bends that are difficult for ResoNix Guardian to conform to, consider using ResoNix Lockout instead
• (Ideal for vintage vehicles; will be difficult for modern vehicles) 100% coverage of ResoNix Fiber Mat Silver as the top layer on the engine side of the firewall

       In Stage-4, we enhance the comprehensive treatment of Stage-3 by adding a full layer of ResoNix Barrier to the interior side of the firewall. This stage focuses solely on the firewall to maximize sound deadening and thermal insulation, ideal for vehicles where engine noise and heat are significant concerns.

Firewall (Interior Side):

• Step 1: Apply 75–100% coverage of ResoNix Mega CLD Squares to the interior side of the firewall for maximum vibration damping.
• Step 2: Next, apply a full 100% coverage layer of ResoNix Fiber Mat for sound absorption and thermal insulation against conductive heat.
• Step 3: Finish with a 100% coverage layer of ResoNix Barrier to block residual noise and heat transfer into the cabin.

       The recommended order of application is CLD, then Fiber Mat, followed by Barrier. This sequence ensures optimal performance in reducing vibrations, absorbing sound, and blocking heat transfer.

Firewall (Engine Side):

       This step is optional and primarily recommended for vintage vehicles, as it can be challenging on modern vehicles due to space constraints and accessibility. If you choose to proceed:

• Step 1: Apply 75–100% coverage of ResoNix Mega CLD Squares on the engine side of the firewall.
• Step 2: Install a full 100% coverage layer of ResoNix Guardian. If there are curves and bends that are difficult for ResoNix Guardian to conform to, consider using ResoNix Lockout instead for better flexibility.
• Step 3: Apply a 100% coverage layer of ResoNix Fiber Mat Silver as the top layer to enhance radiant heat reflection and provide additional thermal insulation.

Note: Modern vehicles often have adequate factory insulation on the engine side, so additional treatment here may offer diminishing returns.

Hood Treatments Conclude at Stage-3

       Please note that hood treatments are not included in Stage-4. All recommendations for hood sound deadening and thermal insulation conclude at Stage-3.

       By focusing intensively on the firewall in Stage-4, you enhance the barrier between the engine bay and the cabin. The combination of ResoNix Mega CLD Squares, Fiber Mat, and Barrier on the interior side of the firewall provides a highly effective shield against engine noise and heat entering the passenger area. For vintage vehicles, the optional engine side treatments further improve these benefits.

Installation Considerations:

• Access to the Firewall: Gaining access to the interior side of the firewall can be labor-intensive. Ensure you have the necessary tools and expertise before starting this project.
• Material Thickness: Be mindful of the combined thickness of the materials, as it may affect the reassembly of interior components. Measure available space carefully and adjust material choices if necessary.

Order of Application: Following the recommended sequence of CLD, Fiber Mat, then Barrier will yield the best results. However, if installation constraints require a different order, try to maintain the integrity of each layer’s purpose.

Performance: 4/5 for Modern Vehicles with louder engines, and 5/5 for Vintage Vehicles
Difficulty of Installation: 3.5/5 once you have access to the firewall
Overall Value: 1.5/5 for modern vehicles, 2.5/5 for vintage vehicles

Materials

• 75–100% coverage of ResoNix Mega CLD Squares on the interior side of the firewall
• 100% coverage of ResoNix Guardian on the interior side of the firewall. If there are curves and bends that are difficult for ResoNix Guardian to conform to, consider using ResoNix Lockout instead
• 100% coverage of ResoNix Fiber Mat on the interior side of the firewall
• 100% coverage of ResoNix Barrier on the interior side of the firewall
• (Ideal for vintage vehicles; will be difficult for modern vehicles) 75–100% coverage of ResoNix Mega CLD Squares on the engine side of the firewall
• (Ideal for vintage vehicles; will be difficult for modern vehicles) 100% coverage of ResoNix Guardian on the engine side of the firewall. If curves and bends make installation challenging, consider using ResoNix Lockout instead
• (Ideal for vintage vehicles; will be difficult for modern vehicles) 100% coverage of ResoNix Fiber Mat Silver as the top layer on the engine side of the firewall
• (Ideal for vintage vehicles; will be difficult for modern vehicles) 100% coverage of ResoNix Barrier as the top layer on the engine side of the firewall

       In Stage-5, we aim for the ultimate in sound deadening and thermal insulation for your vehicle’s firewall. This level is typically reserved for vintage vehicles undergoing restoration or for enthusiasts seeking the highest level of cabin comfort and noise reduction. For modern vehicles, the marginal gains may not justify the extensive effort and cost, but if you’re striving for perfection, this is the way to achieve it.

Firewall (Interior Side):

1. Apply ResoNix Mega CLD Squares: Start by applying 75–100% coverage of ResoNix Mega CLD Squares to the interior side of the firewall, focusing on large, flat areas for maximum vibration damping.
2. Install ResoNix Guardian: Next, apply a full 100% coverage layer of ResoNix Guardian directly over the CLD layer. This material combines sound absorption, sound blocking, and thermal insulation properties. If your firewall has curves and bends that make ResoNix Guardian difficult to install, consider using ResoNix Lockout instead, as it offers greater flexibility.
3. Add ResoNix Fiber Mat: Apply a 100% coverage layer of ResoNix Fiber Mat over the Guardian (or Lockout). This material provides excellent sound absorption and thermal insulation against conductive heat.
4. Apply ResoNix Barrier: Finish with a full 100% coverage layer of ResoNix Barrier on top of the Fiber Mat. This step enhances noise blocking and further reduces heat transfer into the cabin.

Firewall (Engine Side):

       This step is optional and primarily recommended for vintage vehicles, as it can be very challenging on modern vehicles due to space constraints and accessibility. If you choose to proceed:

1. Apply ResoNix Mega CLD Squares: Apply 75–100% coverage on the engine side of the firewall to dampen vibrations.
2. Install ResoNix Guardian or Lockout: Install a full 100% coverage layer of ResoNix Guardian over the CLD layer. If there are curves and bends, ResoNix Lockout may be a better option due to its flexibility.
3. Add ResoNix Fiber Mat Silver: Apply a 100% coverage layer of ResoNix Fiber Mat Silver as the third layer. This material enhances radiant heat reflection and provides additional thermal insulation, protecting the cabin from engine heat.
4. Apply ResoNix Barrier: Finish with a full 100% coverage layer of ResoNix Barrier on top of the Fiber Mat. This step enhances noise blocking and further reduces heat transfer into the cabin.

Note: Hood treatments conclude at Stage-3. No further treatments are recommended for the hood in Stage-5.

       By following this sequence—CLD, then Guardian (or Lockout), then Fiber Mat, then Barrier—you achieve the most effective combination of vibration damping, sound absorption, thermal insulation, and noise blocking for your vehicle’s firewall.

Installation Considerations:

• Order of Application: The recommended sequence is crucial for optimal performance. Installing ResoNix Guardian (or Lockout) directly over the CLD layer maximizes the effectiveness of both materials. Following with Fiber Mat and then Barrier ensures comprehensive sound and heat insulation.
• Material Thickness: Be mindful of the combined thickness of these layers, as it may affect the reassembly of interior components. Measure available space carefully and adjust material choices if necessary.
• Flexibility Needs: If your firewall has curves and bends, opting for ResoNix Lockout instead of Guardian will make installation easier without significantly compromising performance.

Applicability to Modern Vehicles:

       While Stage-5 provides the highest level of sound deadening and thermal insulation, modern vehicles may not experience substantial benefits over Stage-4 due to existing factory treatments. Carefully consider whether the additional effort and cost align with your desired outcomes.

       By investing the time and resources into a Stage-5 firewall treatment, you’re committing to the highest standards of automotive comfort and performance. Whether you’re restoring a vintage classic or enhancing a modern vehicle, this comprehensive approach will provide unmatched reductions in noise and heat, elevating your driving experience to new heights.

Final Thoughts:

• Installation Challenges: Gaining access to the interior side of the firewall can be labor-intensive, especially in modern vehicles with complex dashboards. Ensure you have the necessary tools and expertise before starting this project.
• Safety Precautions: Always disconnect the battery before working near electrical components or the engine bay. Wear appropriate protective gear and follow all safety guidelines.
• Professional Assistance: Due to the complexity and effort required at this stage, consider seeking professional installation to ensure the best results.

       By tailoring your sound deadening and thermal insulation efforts to the specific needs of your vehicle, whether it’s a modern model with adequate insulation or a vintage car requiring significant upgrades, you can achieve a quieter, cooler, and more comfortable driving experience. Stage-5 represents the pinnacle of what’s possible, offering the most comprehensive solution for reducing noise and heat in your vehicle.