MAT66 ProBlack 80 mil 36 sqft Car Sound Deadening Mat, Butyl Automotive Sound Deadener, Vehicle Audio Sound Insulation and Dampening Material

Do you have an older car or truck with some rattles? Are you dropping in some much improved speakers in your doors? Do yourself a solid by taking the time and a few bucks to lay in some sound deadening material. Mat66 is **awesome**. The package arrived in great shape and well packed. I ordered 36 square feet of 80mil foil clad butyl. It was a HEAVY box.1. Convenience: The pack comes with 34 sheets 15.7x9.8 inch in size. These are perfect for doors or floors or roof. These also cut down nicely with sheers or strong scissors. You can also bench cut them on a cutting mat or nylon cutting board with a utility knife. The sheet size makes it really easy to mock up and design your layout.2. Adhesion: Each sheet has backing paper that peels away easy - you start from one end and slowly take the paper away while securing the adhesive to the surface you are covering. You will need a hand roller or other smoothing tool to press down and form the sheets into all curves, contours, and bumps of the surface. The sheets have these cool bump square indicators on the back foil cladding. If you smooth down all the bumps, the sheet is stuck on there properly. Super simple.3. Value for money: For 36 square feet of 80mil, this was very reasonably priced. I was able to cover all of the interior door shell I could reach, as well as the front face of 2 Chevy truck doors, and coat the inside of both the door cards. I only used about half the box of Mat66 they sent me!4. Tips: Warm it with a hair dryer if working in a cold shop or outside. It shapes into contours and sticks much easier and quicker if warmed. Clean your surfaces well before installing. In the photos you will see I used this as a backer surround for the new Alpine speakers I was installing. Again, by reducing rattle, and stiffening the sheet metal surface the speaker is mounted on - all the better the sound outcome. This also sealed up the OEM opening (closed the small gaps around the speaker). Then by doubling up 2 layers of Mat66 exactly behind the speaker on the outer door shell, you almost completely eliminate vibration and rattle in the door, also equals better sound purity. The weather proofing OEM door plastic had no problem sticking to the Mat66 when I put it back on. I just used the same roller to re-stick the goo that holds the plastic. Lastly, it sticks to itself. If you carefully layer the sheets, making sure to roll them down well, you can go 2 or 3 layers deep for high SPL applications or where you really want to kill road noise like fender wells, doors, and floors.Now I'm looking around for projects to use the rest of the leftover sheets, and when needed, I will buy this product again. - Bolt

I felt compelled to write this review after reading the other one which was clearly false. There was no smell with this product, it was much easier to handle and slice than most other brands. I'm guessing that the negative reviewer stands to gain financially from dissuading buyers from this product, as there are really only two other brands that make a similar product...Installed on the roof so far and the difference it makes when rain is hitting the roof is literally jaw-dropping. Luxury cars tend to have a lot of noise insulation. My car is bare metal on just about every surface with only a cloth covering. You don't have to cover every last square inch with the mats, but tap around the metal and see where it reverbs the most. Once there's little to no sound vibrating through then adding more mats wont really help reduce noise conduction.73-75dBA on a smooth highway before any product was applied. Will update once I get the rest of the vehicle.Update:I ended up buying three packs of this to do an entire compact sedan. I have it on the roof, the floor, and the doors. Contrary to the (possibly paid) negative reviews, it is not falling off the roof. Driving in heavy rain there was not a single sound of rain coming in through the roof - just the windshield, which made for a significantly quieter ride in the rain, especially for backseat passengers.There is a notable difference in how well the car holds cold/hot air. However, my car does not seem as hot as before when I get back in after going shopping. I do have 150mil foam above the butyl mats, which probably contributes to its thermal properties. Parking lot asphalt will radiate up from the floor of your car, the sun will cook your car from the roof. Having both these areas double insulated sure helps. Sitting in traffic with the air blasting I used to notice more heat radiating from the roof and even the floor was a heat zone, both of which would diminish once the car started moving because of air mitigating the heat from the sun/asphalt. I no longer notice either heat zones when stationary.In terms of noise reduction.... My car is now 64dBA on the same stretch of highway at 70mph!! Effectively a 50% reduction in noise. I can turn my speakers down now too! Cars passing by are essentially inaudible. If there was a way to soundproof the glass, they would be completely inaudible and it might be too quiet. I did not measure how loud my car was around town before this, but 56dBA around town right now.By comparison, a vacuum is 75dBA, an electric toothbrush is 60dBA and a refrigerator is 50 dBA.I used a layer of MAT66 + a layer of 150mil closed cell foam on the roof, the floors. I used a layer of MAT66 + 150mil closed cell foam on the inside of the doors, and another layer of MAT66 on the inner door where the door panels would cover + another layer of closed cell foam on the plastic door panels. Maybe a bit overkill on the doors, but I had extra material and figured that would yield the most benefit.The firewall may be the hardest part of installation because you have to remove the dash. It's not critical, but if you want to maximize roadnoise elimination then you'll have to remove the dash, drain and disconnect the ac, and get to rolling. I did not want to do this step, but it might be easier to cover the firewall from inside the engine bay with a heat resistant material. For now, I'll enjoy my ride like this.