ResoNix Sound Solutions

Premium Automotive Sound Treatment Solutions

ResoNix Sound Solutions Sound Deadening Buyers Guide

How Much Sound Deadening, Decoupler, Sound Absorber, & Noise Barrier To Use In Your Vehicle’s Sound Treatment Installation

ResoNix Buyers Guide Cover Photo how much sound deadener should i use what kind of sound deadener should i use

Hey everyone, Nick here. ” How much sound deadening, what exact products, and where should I apply them” is by far my most commonly seen set of questions. This article will be detailing as much as possible regarding these questions, and I hope to be able to provide as much information about this as possible. In this article, we will be going over my suggested generalized kits that apply to certain areas of a vehicle. How much sound deadener, and what exact products will be detailed below. Keep in mind, every car is different, but this should be very close to most situations. These kit suggestions will range from Stage-1, up to Stage-5. Stage-1 being my bare-minimum suggestion, while Stage-5 would be maximum performance.

 

Rating The Various Sound Deadening Kits

I am also going to be rating general overall performance, difficulty of installation, and value on a scale of 1-5. The value will be assigned based on a generalized ratio of how much performance you are getting relative to the cost as well as the effort required to install the package in question. Remember, none of these are my hard set recommendations and apply perfectly to every situation. They are just a guideline. You can also borrow tips from higher Stages to do what is necessary for your specific application, but it is important to stick to the recommended kits as they are. There is a reason why I am recommending them as shown. If you have any questions about your installation, please do not hesitate to reach out.

 

Notes

Note: Based on how I wrote this, I suggest reading each Stage for each section of the vehicle that you are interested in. As I work my way up, the details that are added from the subsequent Stage are sometimes left out in order to save from repetitiveness. A bulk of the info will usually reside between Stage 1 and Stage 3.

 

Another Note: I also HIGHLY recommend reading the Reference Information & Guide page, or at least its General Synopsis section before fully diving into this. If you do not already have a full understanding of how these products work, this article will create questions of its own. This will be alleviated by first reading the Reference Information & Guide page. I know it’s a lot of reading, but I promise, reading these in the suggested order will help everything make sense. If this is the first page you are coming across from ResoNix, I highly suggest reading the Reference Information page first. It is the largest wealth of information on different sound deadening products, and how to sound deaden your car. This article should be read after, and will detail how much sound deadener and other automotive sound treatment products to use in order to get the end result you are looking for. 

       Before we get into the different sections of the vehicle and the different stages of treatment, let’s go over what areas of a vehicle are most important to treat first. We will break this down into two sections, first for sound system installation purposes, and the second being for just lowering overall noise while driving. This is a HIGHLY generalized ranking as every vehicle is different, but I am basing this off my experience and my knowledge about vehicles and how these products work. These will also be ranked 1-5. 1 being low importance, 5 being the highest importance. 

Sound System Installation Sound Deadening Areas Of Importance

Doors: 5/5 if there is a door-mounted midbass driver, 2/5 if the midbass is in the kickpanel, under the seat, or elsewhere.

Roofs: 4/5 if no sunroof, 2/5 if there is a sunroof.

Wheel Wells: 1/5 for parked listening, 2/5 while driving. It lowers the noise generated by your tires while driving, but doesn’t directly improve the sound system.

Floors: 1/5. This area is not very important for a sound system in most vehicles. Slightly more important for larger trucks, but still nothing important.

Rear Parcel Shelf & Rear Pillars: 4/5. In most sedans these are important to treat to reduce rattle and resonance caused by the subwoofer in the trunk.

Trunk Lids, Rear Hatches, & Rear Walls of Trucks: 3/5. More important in hatches and trucks than in sedans. 

General Driving Noise Floor Reduction Sound Deadening Areas Of Importance

Doors: 4/5

Roofs: 5/5 if no sunroof, 2/5 if there is a sunroof.

Wheel Wells: 5/5 for trucks with large tires, 4/5 for normal sedans, 2.5/5 for luxury cars.

Floors: 4/5 if doing 100% coverage with a noise barrier or sound absorber. 1/5 if only doing a constrained layer damper. 2/5 for constrained layer damper only on larger trucks or older vehicles.

Rear Parcel Shelf & Rear Pillars: 2/5

Trunk Lids, Rear Hatches, & Rear Walls of Trucks: 3.5/5. More important in hatches and trucks than in sedans. 

Car Door Sound Deadening

       Let’s start with the most common area to apply sound treatment products to, the doors. How much sound deadening, sound absorbers, noise barriers, and other treatments should I use in my doors is a question I get multiple times a day. Let’s dive into it. The doors are going to be very similar between most vehicles. The only real differences some may experience is how large the door is, how large the access holes are on the inner door skin, and how much space is between said inner door skin and the door panel itself. Please note, we also have a fully detailed write-up on how we sound treat doors to Stage-4 level performance in our How To Sound Deaden Doors blog post. How much sound deadening should I use in my car doors? What sound deadener should I use in my door? Find out below.

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 Super Max Mega Pro CLD Squares)

. 1 Sheet of ResoNix Fiber Mat 25 or ResoNix Fiber Mat 45 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 Super Max Mega Pro CLD Squares sound deadening material. Use original ResoNix CLD Squares in areas where SMMP CLD Squares are too difficult to conform.

. 100% coverage of ResoNix Fiber Mat 25 or ResoNix Fiber Mat 45 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 7, 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 Super Max Mega Pro 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 Super Pro Mega Max 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 Super Max Mega Pro CLD Squares. This is for installation on the door panel ONLY IF the door panel would be too difficult to install the ResoNix SMMP 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 Super Max Mega Pro CLD Squares sound deadening material. Use original ResoNix CLD Squares in areas where SMMP CLD Squares are too difficult to conform.

. 100% coverage of ResoNix Fiber Mat 25 or ResoNix Fiber Mat 45 sound absorber and decoupler material. 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 SMMP 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 Super Max Mega Pro CLD Squares sound deadening material. Use original ResoNix CLD Squares in areas where SMMP CLD Squares are too difficult to conform.

. 100% coverage of ResoNix Fiber Mat 25 or ResoNix Fiber Mat 45 sound absorber and decoupler material. 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 Super Max Mega Pro CLD Squares, even better (if you can, you will probably need more than 20 square feet of ResoNix Super Max Mega Pro 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.

Car Roof & Headliner Sound Deadening

       Next up is, in my opinion, the most overlooked and underrated area to treat in a vehicle, the roof. If your roof doesn’t have a window, this is going to be the largest, flattest, and most resonant panel in your entire vehicle, all while it features a lot of turbulence from wind. Long story short, this area is a huge offender of wind noise and resonance just from driving. When it comes to sound systems, the low frequencies from the subwoofers cause low frequency resonance of the roof skin, which will be heard as muddiness, distortion, and “slow” bass. Treating your roof is one of the quickest and easiest ways to improve the low frequency transient response in your cars sound system.

       If your roof does have a window (sun or moon roof), this step isn’t AS important since the glass isn’t resonant and stabilizes the rest of the roof skin a bit, but is still what I would consider an important step. A window also makes the installation more difficult and there are more parts that need to be removed or taken care of before installation can begin, and you need to account for the movement of the window and to not block the window or the tracks/mechanism. How much sound deadening should I use in my cars roof? What sound deadener should I use in my cars roof? Find out below.

Note: I get a lot of pushback about sound treating a vehicle’s roof from customers since they think it is going to be a ton of work. I assure you, it is much less work and much less difficult than you could imagine in most cases. Most of the time you don’t even need to remove the headliner from the interior of the vehicle. You can just drop it and work around it. For your average, everyday cars, this can be as little as a 1-2 hour job for our Stage-1 recommended kit, or 4-8 hours for our Stage-4 recommended kit. Stage-5 will be a bit difficult and time consuming though and I definitely recommend removing the headliner from the vehicle if you are crazy enough to go this far.

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 Super Max 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 Super Max Mega Pro 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 Super Max Mega Pro CLD Squares).

. 1 Roll of ResoNix Butyl Rope

. 100% coverage of ResoNix Fiber Mat 25 or 45 (I’d wager 95% of vehicles can get away with Fiber Mat 45 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 Super Max Mega Pro CLD Squares sound deadening material).

. 1 Roll of ResoNix Butyl Rope

. 100% coverage of ResoNix Fiber Mat 25 or ResoNix Fiber Mat 45 sound absorbing material (I’d wager 95% of vehicles can get away with Fiber Mat 45 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 CLD Super Max Mega Pro CLD Squares sound deadening material

. 1 Roll of ResoNix Butyl Rope

. 100% coverage of ResoNix Fiber Mat 25 or ResoNix Fiber Mat 45 sound absorber material. Preferably Fiber Mat 45 if it can fit.

. 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 CLD Super Max Mega Pro CLD Squares sound deadening material

. 1 Roll of ResoNix Butyl Rope

. 100% coverage of ResoNix Fiber Mat 25 or ResoNix Fiber Mat 45. Preferably Fiber Mat 45 if it can fit.

. 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 Super Max Mega Pro 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.

Wheel Wells & Fender Liners Sound Deadening - How To Reduce Tire Noise

       Next up is another highly overlooked and underrated area to treat in a vehicle, the wheel wells. Sound treating wheel wells on a vehicle is something relatively new for most circles, and how much sound deadening material and sound absorber to use is a question most have. Frankly, if you are a car audio sound quality competitor and you only care about what your car sounds like when it’s parked, this isn’t for you. But if you are trying to lower the overall noise floor from road, wind, and tire noise while driving and getting the benefit of that to improve your cars sound system while driving, this is a relatively quick, easy, and inexpensive way to make a large improvement on most vehicles. How much sound deadening should I use in my cars wheel wells? What sound deadener should I use in my cars wheel wells? Find out below.

       Note: This is only for vehicles that have fender liners in their wheel wells. If your wheel well is fully exposed, there is not much you can do short of fabricating or purchasing a fender liner for your car. While not common, I have run into this when helping a couple of customers in the past.  

       Note 2: This will only have three stages of recommendations. There is not much to really do here.

       Also, see our ResoNix Blog article on how to reduce tire noise by sound deadening your wheel wells and fender liners. How To Reduce Sound In Your Car By Sound Deadening Your Wheel Wells

Performance: 2/5

Difficulty of Installation: 2/5

Overall Value: 2/5

 

Materials

. 15-20 Square Feet of ResoNix CLD Squares sound deadening material

       Our ResoNix Stage-1 suggested sound deadening kit for wheel wells is very simple, but honestly, I cannot think of a single situation where I wouldn’t tell someone that they shouldn’t just step up to Stage-2 considering the relatively low cost difference compared to the performance gains. This is why I put the overall value pretty low. The Stage-1 recommended kit for wheel wells is just enough ResoNix CLD sound deadening to treat the fender liner itself, and possibly the cars metal wheel well if appropriate.

       While some may say this is a useless upgrade since a fender liners resonance is inaudible, I only agree with the later part of that claim. Yes, the resonance of a fender liner is going to be completely inaudible when sitting inside of your car. BUT, that fender liner isn’t very mechanically coupled to the cabin of your car. This means having full coverage of ResoNix CLD will act as a noise barrier around the wheels, and help reflect noise away and out of the wheel well. The installation difficulty will drastically depend on the car. Some fender liners are very easy to remove, and some are difficult. Suggested practice would be to jack the car up, put it on stands, and remove the wheels to make this as easy as possible.

Performance: 4/5

Difficulty of Installation: 2.5/5

Overall Value: 4/5

 

Materials

. 15-20 Square Feet of ResoNix CLD Squares sound deadening material

. 1 or 2 Sheets of ResoNix Fiber Mat 25 or Fiber Mat 45 sound absorber and decoupler material. Preferably Fiber Mat 45 if it can fit without issue. Enough for full coverage on all 4 fender liners.

       Our ResoNIx Stage-2 suggested sound deadening kit for wheel wells is also very simple. The Stage-2 recommended kit for wheel wells is the same procedure as our Stage-1 recommendation, which is to do full coverage of ResoNix CLD sound deadening on the fender liners and spot treating the wheel wells on the body, but with the addition of also doing full coverage of ResoNix Fiber Mat on the fender liner as well. The key here is to find out what you can actually fit, as trying to do Fiber Mat 45 sound absorber on a car that has tighter tolerances in this area will prove to be very difficult to reinstall the fender liner. Remember, when using a sound absorber such as ResoNix Fiber Mat, you want to leave it as lofted as possible for it to perform best. Using ResoNix Fiber Mat 45 sound absorber when there is only enough space for 25 to not be compressed will yield results that aren’t great. Heads up, I haven’t done every car, so you will most likely have to do some pre-purchase inspection yourself on your own car to see what you can fit.

Performance: 5/5

Difficulty of Installation: 4/5

Overall Value: 2.5/5

 

Materials

. 15-20 Square Feet of ResoNix CLD Squares sound deadening material

. 1 or 2 Sheets of ResoNix Fiber Mat 25 or ResoNix Fiber Mat 45 sound absorber material. Preferably Fiber Mat 45 if it can fit without issue. Enough for full coverage on all 4 fender liners.

. 2 or 3 Sheets of ResoNix Barrier. Enough for full coverage on all 4 fender liners.

       Our ResoNix Stage-3 suggested sound deadening kit for wheel wells is again, just one more simple step. First layer is full coverage of ResoNix CLD Squares sound deadening material, the second layer is full coverage of ResoNix Barrier, and the third layer would be the ResoNix Fiber Mat, all applied directly to the fender liners. What makes this install a bit difficult is securing the ResoNix Barrier to the fender liner. You can possibly use small black stainless steel bolts with stainless steel fender washers and nuts on the other side. I have yet to do this type of install honestly, but this is how I think I would attempt it. Once that is installed, top it off with ResoNix Fiber Mat.

Car Floor (Includes Trunk Floor) Sound Deadening Recommendations

       Next up is the floor. This is where things get a bit trickier. How much sound deadening, sound absorber, and/or noise barrier to use on your vehicles floor is a topic of debate in many circles. As mentioned in the opening paragraph of this article, every vehicle is different. Well, this is where things get very different from vehicle to vehicle. My Volvo sedan needs a completely different quantity and approach than the last car I received an inquiry for, a 2000 Ford Excursion.

       Some cars, especially newer sedans and some SUV’s have floors that are very strong due to the shape. Most modern vehicle floors are not perfectly flat sheet metal anymore. They have curves, bumps, dips, and all sorts of things supporting them. Older cars, and even some modern trucks and even some SUV’s have floors that are much flatter and larger. This means that they are more resonant.

       What I’m getting at, the source of noise as far as the floor goes might be much different in my car than it is in yours. This is where you really need to start understanding how these products work, why they work, and how to use them and just use this as a GUIDE to get an idea of what to do in your situation. Our Reference Information & Guide page provides a ton of useful info to explain how these products work, and should clear up any questions you might have.

       I’d say in about 75% of cases, the floor is going to be the lowest value section of the car to treat, but will necessary if you are trying to block/absorb exhaust, engine, road, and tire noise. The reason I say it is a lower value not because you don’t get much out of treating it, but instead due to how large it is and how much work needs to be done in most cases. But again, if you are trying to make a large impact on lowering noise in your vehicle, the floor is a necessary evil in most cases. How much sound deadening should I use on my cars floor? What sound deadener should I use on my cars floor? Find out below.

Note: For floors, I am only going to go by percentage of coverage instead of an actual amount, since floors can vary drastically in size and amount needed. It is up to you to figure out how much that is. All you need is a tape measure to figure that out.

Note 2: For Floors, we will only have Stage-1 through Stage-4

Performance: 1/5 for most modern sedans, 2.5/5 for older vehicles, and 2/5 for some larger modern trucks (F150, Silverado, etc)

Difficulty of Installation: 2/5

Overall Value: 1/5 for most modern sedans, 2/5 for older vehicles, and 2/5 for some larger modern trucks (F150, Silverado, etc)

 

Materials

. 25-35% coverage of ResoNix CLD Squares sound deadening material

       Our ResoNix Stage-1 suggested sound deadening kit for floors is in my opinion, not really worth it in MOST vehicles considering the amount of work it will require. In some older vehicles or vehicles like Jeep Wranglers, it may be much easier and more beneficial. But the amount of work required relative to the performance makes this a low value. If your car is already stripped for one reason or the other, than this is quick and easy. But starting with a completed and assembled interior of a vehicle will make this a lot of work for a small benefit.

       So, how much sound deadener for our Stage-1 floor recommendation? The Stage-1 suggested kit is just 25-30% coverage of ResoNix CLD Squares sound deadening on the floor. This will help more on older vehicles and trucks with flat floors since they have less strength and rigidity in the floor pans vs modern sedans. This will help a bit with drone, which is usually caused by exhaust and road noise exciting the floor pans and causing them to resonate. This will help handle that. Remember, larger pieces will perform better than multiple smaller pieces, and focus on the flat areas that are resonant. Not the strong areas that have support from dips, curves, bends, or bumps.

Optional Upgrade: Switch to ResoNix Super Max Mega Pro CLD Squares sound deadening material for even better performance.

Performance: 2.5/5 for most modern sedans, 3.5/5 for older vehicles, and 3.5/5 for some larger modern trucks (F150, Silverado, etc)

Difficulty of Installation: 2.5/5

Overall Value: 2.5/5 for most modern sedans, 4/5 for older vehicles, and 4/5 for some larger modern trucks (F150, Silverado, etc)

 

Materials

. 50% or more coverage of ResoNix CLD Squares sound deadening material

. 75-100% coverage of ResoNix Fiber Mat. Most will require Fiber Mat 25 to fit under carpets. Some may be able to fit Fiber Mat 45.

       Our ResoNix Stage-2 suggested sound deadening kit for floors is a pretty large leap in performance and product amount. But there is not much point in doing anything in between what Stage-1 is, and what this Stage-2 recommendation is. Just like in the Stage-1 recommendation, we are going to start with ResoNix CLD Squares sound deadener material. This time, we are going to do a minimum of 50% coverage, but aim for 75% coverage or more if possible. How much coverage I suggest will really depend on how resonant your floor is. The larger/flatter the floor is, the more coverage I recommend. Remember, focus on the large flat areas more than the structured areas, and use larger single pieces as opposed to multiple smaller pieces to get the most performance.

       From here, we are going to apply ResoNix Fiber Mat. Most vehicles will require Fiber Mat 25 under the carpet in order to fit the carpet back in, especially modern sedans, but some may be able to fit the Fiber Mat 45, which will perform much better if it can indeed fit. If it doesn’t fit, don’t sweat it and stick with Fiber Mat 25. In most cases, you will be sticking this on top of the CLD directly, and preferably with 100% coverage. Be sure to not cover any wires, modules, mounting holes/posts, or anything else that may require service in the future.

       If you are not doing 100% coverage, focus on areas that are closest to the source of the noises you are hearing. Transmission tunnels, rear seat areas, rear floors in trucks with loud exhaust, etc. If your vehicle features a carpet that has a backing that is hard, you can stick the Fiber Mat directly to the back of the carpet if you desire, which will leave the floor fully and easily serviceable in the future.

Optional Upgrade: Switch to ResoNix Super Max Mega Pro CLD Squares sound deadening material for even better performance.  

Performance: 3/5 for most modern sedans, 4/5 for older vehicles, and 4/5 for some larger modern trucks (F150, Silverado, etc)

Difficulty of Installation: 2.5/5

Overall Value: 3/5 for most modern sedans, 2.5/5 for older vehicles, and 2.5/5 for some larger modern trucks (F150, Silverado, etc)

 

Materials

. 50% or more coverage of ResoNix Super Max Mega Pro CLD Squares sound deadening material

. 100% coverage of ResoNix Barrier

       Our ResoNix Stage-3 suggested sound deadening kit for floors is also pretty straightforward. The major change here from the Stage-2 recommendation is swapping ResoNix Fiber Mat sound absorber for ResoNix Barrier noise barrier, as well as the swap from ResoNix CLD Squares to ResoNix Super Max Mega Pro CLD Squares sound deadening material. ResoNix Barrier, while being easier to install underneath a carpet, is also going to have better low frequency reduction performance which increases my performance rating, but will be a good amount more expensive, which lowers my overall value rating. Again, once you install your ResoNix CLD onto the floor, just apply 100% coverage of ResoNix Barrier over it.

       The main difference in the install here is that you really do need 100% coverage when using a noise barrier due to how they work. If you leave gaps between sheets, seams that aren’t sealed between sheets, or open areas, you will be drastically reducing its performance. This is because a noise barrier doesn’t convert sound energy into a different type of energy. It stays sound energy and travels elsewhere. If there are opens, it’ll still travel right on in.

Performance: 4.5/5 for most modern sedans, 5/5 for older vehicles, and 5/5 for some larger modern trucks (F150, Silverado, etc)

Difficulty of Installation: 4.5/5

Overall Value: 3.5/5 for most modern sedans, 3/5 for older vehicles, and 3/5 for some larger modern trucks (F150, Silverado, etc)

 

Materials

. 75% or more coverage of ResoNix Super Max Mega Pro CLD Squares sound deadening material

. 100% coverage of ResoNix Barrier

. 100% coverage of ResoNix Fiber Mat sound absorber & Decoupler

       Our ResoNix Stage-4 suggested sound deadening kit for floors is the most I recommend going for normal vehicles. It is a combination of 100% coverage of ResoNix Super Max Mega Pro CLD Squares, ResoNix Fiber Mat, and ResoNix Barrier. I don’t think I even need to explain much since there really isn’t much nuance that hasn’t been mentioned in the previous stages. The only recommendation, layer it in this EXACT order for best results (only applicable on the floor, other areas of the car are different): ResoNix Mega CLD Squares sound deadening on the metal of the floor, Fiber Mat on top of the Mega CLD Squares, and Barrier on top of the Fiber Mat. This way, the ResoNix Barrier is decoupled from the panel (floor in this case) even better, and also cushioned from above with the carpet.

Rear Parcel Shelfs, Trunk Lids, Rear Hatches, & Rear Walls of Trucks Sound Deadening Recommendations

       Next up is the trunk lid/rear hatch. For trunk lids, many people put this as their first priority in the car audio community due to rattles in the trunk from a subwoofer. I don’t think it is very high on the list of importance for that, or for general driving and think it’s a bit blown out of proportion. This is more so the case in sedans. Hatchbacks, SUV’s, and wagon’s rear hatch are more important since they do not have rear seats to help block and absorb any noise coming from the rear of the car. How much sound deadening should I use on my car trunk? What sound deadener should I use on my car trunk? Find out below.

Note: This part of the vehicle will only be Stage-1 through Stage-3 and will also be depicted in percentage of coverage.

Performance: 2/5

Difficulty of Installation: 1/5

Overall Value: 2/5

 

Materials

. 50%~ coverage of ResoNix CLD Squares sound deadening material

       Our ResoNix Stage-1 suggested sound deadening kit for trunk lids and rear hatches is a very simple one. It is only 50% coverage give or take of ResoNix CLD Squares. This will help reduce resonance from the trunk lid and rear hatch. Remember, use larger singular pieces as opposed to multiple smaller pieces for better performance.

Tip: How much sound deadener your trunk lid or hatch can handle is important to keep in mind.  In some vehicles with electronic trunks/hatches, adding weight can cause them to not function correctly. Tesla’s are notoriously sensitive in this regard.

Optional upgrade: Do more coverage of CLD and/or switch to ResoNix Super Max Mega Pro CLD Squares sound deadener for even better performance.

Performance: 4/5

Difficulty of Installation: 2/5

Overall Value: 4/5

 

Materials

. 50%~ coverage of ResoNix CLD Squares sound deadening material

. 100% Coverage of ResoNix Fiber Mat sound absorber and decoupler

. Spot treat plastic clips and creases with ResoNix Butyl Rope if applicable

       Our ResoNix Stage-2 suggested sound deadening kit for trunks and hatches adds the addition of ResoNix Fiber Mat to the mix. As usual, use 45 if possible, or 25 if tolerances are on the tighter side. The addition of ResoNix Fiber Mat as a sound absorber and a decoupler will achieve three things. It will help decouple the rear hatch panel and prevent rattles if it’s a plastic panel. It will absorb noise that is entering through this area of the vehicle. And, it’ll help stabilize the rear panel to prevent further buzzes and resonance, especially if it’s a plastic panel commonly seen on rear hatches.

Optional Upgrade: Do more coverage of ResoNix CLD Squares sound deadener and/or switch to ResoNix Super Max Mega Pro CLD Squares sound deadening material for even better performance.

Performance: 5/5

Difficulty of Installation: 4/5

Overall Value: 2.5/5

 

Materials

. 100%~ coverage of ResoNix Super Max Mega Pro CLD Squares sound deadening material

. 100% Coverage of ResoNix Fiber Mat sound absorber and decoupler – 2 layers (details below)

. Spot treat plastic clips and creases with ResoNix Butyl Rope if applicable

. 100% coverage of ResoNix Barrier

       Our ResoNix Stage-3 suggested sound deadening kit for hatches (I can’t picture doing this on a trunk lid to be honest) adds the addition of another layer of ResoNix Fiber Mat, and a layer of ResoNix Barrier. It also swaps the ResoNix CLD Squares sound deadening material for the ResoNix Super Max Mega Pro CLD Squares. The additional layer of ResoNix Fiber Mat is to sandwich the ResoNix Barrier in between the Fiber Mat layers. This will help create a totally decoupled ResoNix Barrier layer while still being able to put some pressure to add stability on the panel.

Note: I cannot picture a situation in which you would be able to fit two layers of Fiber Mat 45. If you plan on doing this, it’s probably best to stick with the two layers of Fiber Mat being the 25 version. And again, how much sound deadening you use can affect the operation of the trunk lid or hatch. Be sure to plan accordingly.

Featured Products

  • ResoNix Sound Solutions CLD Squares Sound Deadener Sound Deadening Material with Free ResoNix Roller

    ResoNix Sound Deadener – CLD Squares – Full Box: 40 Pieces (40 Square Feet)

    $340.00
  • ResoNix Sound Solutions Fiber Mat 45

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

    $125.00
  • ResoNix Solderless Custom RCA Cable System

    Solderless RCA Cable System – Dual Coaxial Cable

    $3.00
  • ResoNix Sound Solutions CCF Strips Speaker Rings Fast Rings Foam Speaker Ring

    ResoNix CCF Strips – Foam Speaker Ring Strips For Speaker-To-Panel Coupling – Pair

    $40.00
  • ResoNix Sound Solutions Guardian Hydrophobic Melamine MLV Composite sound absorber for cars rear wave absorber midbass diffuser Mass Loaded Vinyl

    ResoNix Guardian – Automotive Sound Absorbing Pad

    $330.00
  • ResoNix Solderless Custom RCA Cable System End Silver

    Solderless RCA Cable System Connectors – Silver – Pair

    $8.90