Sound Deadener Showdown
Version 2 Updated: October 19, 2005
Products Reviewed: B-Quiet Extreme and Ultimate, Brown Bread, Cascade Audio Engineering VB2, Dynamic Control Dynamat Original and Dynamat Xtreme, Elemental Designs eDead v1 and eDead v1SE, FatMat, RAAMaudio RAAMmat BXT, Second Skin Damplifier and Damplifier Pro,
Temperature Tests
Heat
Why bake sound deadening mats in the oven? It can get incredibly hot inside a car. Take a black car, leave it outside in the sun during a hot summer day and it can easily reach temperatures that exceed the rating for roofing materials. Since one of my reasons for undertaking this project was to try and unravel the asphalt mat failure problem, testing heat resistance is a critical step.
Getting to the bottom of this problem was tough. Some of the sellers of asphalt mats consistently cite user error as the source of all problems. This just doesn't make sense. Failed installations plague both the most meticulous and the most careless installers. Thorough cleaning of the mounting surface, using a heat gun and a complete and vigorous going over with a roller don't seem to make a difference.
There are two classic failure scenarios. In the worst case, the asphalt adhesive liquefies. This seems pretty straightforward. Too much heat. The second category is more complicated. The mat falls off a vertical or inverted surface leaving a transparent brown residue behind. Attempts to remount the mat fail. It isn't sticky anymore.
Some of the most trouble prone products are sold on Web sites describing the special characteristics of the Pressure Sensitive Adhesive used to secure the mat in place. One details a "rubberized compound that is fused with a 1 mil Acrylic PSA". In the face of this and similar descriptions it would be reasonable to believe that such a thing existed. It occurred to me that the PSA might be failing for some reason, separating from the asphalt layer causing the mat to fall off, accounting for the brown residue and the mat no longer being stick. Sounds good right? Unfortunately, there is no distinct PSA on these deadeners. The asphalt/SBR compound is the adhesive. Back to the drawing board.
Long story short, I am convinced that heat is the culprit in these failures as well. The SBR compound deteriorates over time. The volatile compounds that keep the asphalt flexible and sticky escape and there you go. If any one has a better explanation, please let me know.
In any event. We know cars get hot. Testing the heat resistance of these things seems like a good idea. In version 1 of Sound Deadener Showdown. I mounted the mats and heated them fairly rapidly - increasing the temperature ten degrees or so every fifteen minutes. Most of the mats failed, but at temperatures much higher than I would expect them to ever encounter in a car.
Then it dawned on me. Cars are exposed to temperature extremes for hours at a time. This is what I am trying to simulate with this new test sequence.
Methodology
I tried to design a test to severely stress the mats I collected for this review. I don't have any specialized laboratory equipment, just a kitchen oven and a collection of tools. Here's what I did.
I built a test rig from galvanized steel sheet metal consisting of a base and a back plane to which I would attach the products. The back plane leans forward from vertical approximately 30° to partially simulate the effect of inverted installation.
I cut two 1 inch by 6 inch strips from each of my samples. Before attaching the sample strips to the back plane, I cleaned it with acetone and then denatured alcohol. Finally, I wiped it down with a clean microfiber towel to make sure there was no dust or link on the surface.
To simulate a less than perfect install, and to increase the effect of gravity, I put two thoroughly cleaned 1/4 inch steel washers between the galvanized steel and the mat, top and bottom of the strip, about 1/4 inch in from the ends. You can see the bulge under several samples.
I used a roller vigorously on each strip. I wiped the back of the mounted strip and then mounted the second identical sample on top of the first, this time with the washer in the center of the mat. When all were installed, I wrapped the base in aluminum foil - to make it easier to clean up, then covered the entire oven rack with foil to prevent dripping on to the oven floor - to prevent the girlfriend wrath that a baked in mess would likely bring. I placed four 5 pound cast iron disks on the bottom rack of the oven to help stabilize the temperature. I used four thermometers to monitor the temperature, never less than two at a time
Once prepared, I put the test rig and a thermometers on the rack and took the first photograph. I repeated this process several times to verify my results.
I want to emphasize that I am not even pretending that these temperatures are accurate. I believe they are within 5°F or so, but will not stand behind any sort of exact failure point. The important thing to be learned from this test are the relative failure points, or in the case of the Second Skin mats the complete lack of failure.
I have marked the first image where failure is obvious a red background.
This test is not meant to provide any sort of definitive ranking of products. It only provides one point of comparison, one little piece of information that will help us evaluate an important property of our test subjects.
The Results - listed from first failure to last - by name if tied
| Product Name | Product of | 00:00 140°F | 02:00 160°F | 03:00 160°F | 04:00 180°F | 05:00 180°F | 06:00 180°F | 00:00 180°F | 02:00 180°F | 03:00 200°F | 04:00 240°F | 06:00 260°F | 07:00 260°F | 00:00 500°F | 00:15 500°F | 00:30 500°F |
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| Brown Bread |
StereoTypes Regina, SK Canada Web site |
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| B-Quiet Extreme |
StereoTypes Regina, SK Canada Web site |
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| Dynamat Original |
Dynamic Control of North America, Incorporated Hamilton, OH Web site |
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| eDead v1SE |
Elemental Designs L.C. North Liberty, IA Web site |
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| FatMat |
Fatmat Sound Control North East, PA Web site |
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| eDead v1 |
Elemental Designs L.C. North Liberty, IA Web site |
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| B-Quiet Ultimate |
StereoTypes Regina, SK Canada Web site |
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| RAAMmat BXT60 |
RAAMaudio St Helens, OR Web site |
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| Dynamat Xtreme |
Dynamic Control of North America, Incorporated Hamilton, OH Web site |
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| Damplifier |
Second Skin Audio Queen Creek, AZ Web site |
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| Damplifier Pro |
Second Skin Audio Queen Creek, AZ Web site |
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Cold
I wanted to see what would happen when the products freeze. I also took this opportunity to compare the effects of using a heat gun on the samples during installation.
I took a sheet of galvanized sheet metal and cleaned it the usual way - acetone, denatured alcohol and a final micro-fiber wipe down. I cut two 1"x3" pieces from each product. I mounted the first set of samples using a heat gun and roller. After the assembly cooled to room temperature, I mounted the second set of samples, unheated but rolled, each immediately below its previously installed twin.
I sealed the entire thing in two plastic bags and placed it in the freezer. I left it there for 24 hours, removed it and dropped the test assembly, perpendicular to the floor, on to a carpeted floor from four feet. I repeated this process three times - freeze for 24 hours, drop, back into the freezer.
After the third cycle, I unwrapped the test panel and mounted it vertically in a clamp to allow it to gradually warm to room temperature. I should mention that the unheated Brown Bread sample was completely detached.
After 4 hours, I lightly flicked the edge of each sample with a fingernail - not to pull it away, more just to see if it was still bonded to the sheet metal. All of the mats except for the eDeads and Brown Bread remained in place. The heated Brown Bread sample was fine, the unheated sample fell off. The unheated eDead v1 sample was partially detached. Both the heated and unheated eDead v1SE samples were partially detached.
In each case, the samples applied with the heat gun seemed to have a stronger bond than those applied at room temperature. I have to wonder if using a heat gun to install asphalt mat might actually hasten its deterioration? It only takes a few seconds with the gun to melt the asphalt adhesive. This would explain why so many of the reports of failure come from people who really put in some effort - clean the surface, heat the mat and roll it down. The process of installation may be sowing the seeds for future failure.
In each case, the heat gun mounted sample is above the room temperature mounted sample.
The Results - listed alphabetically, by name.
| Product Name | Product of | Image |
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| B-Quiet Extreme |
StereoTypes Regina, SK Canada Web site |
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| B-Quiet Ultimate |
StereoTypes Regina, SK Canada Web site |
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| Brown Bread |
StereoTypes Regina, SK Canada Web site |
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| Damplifier |
Second Skin Audio Queen Creek, AZ Web site |
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| Damplifier Pro |
Second Skin Audio Queen Creek, AZ Web site |
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| Dynamat Original |
Dynamic Control of North America, Incorporated Hamilton, OH Web site |
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| Dynamat Xtreme |
Dynamic Control of North America, Incorporated Hamilton, OH Web site |
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| eDead v1 |
Elemental Designs L.C. North Liberty, IA Web site |
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| eDead v1SE |
Elemental Designs L.C. North Liberty, IA Web site |
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| FatMat |
Fatmat Sound Control North East, PA Web site |
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| RAAMmat BXT60 |
RAAMaudio St Helens, OR Web site |
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| VB2 |
Cascade Audio Engineering Bend, OR Web site |
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Observations
SecondSkin Damplifier and SecondSkin Damplifier Pro both survived this test like champs. Dynamic Control's Dynamat Xtreme also demonstrated heat resistance well beyond the second group of products.
RAAMmat BXT™ and B-Quiet Ultmate came out in the middle of the pack. Higher temperature resistance than the asphalt products, and less tolerant than the SecondSkin and Dynamat Xtreme samples. Of interest is the manner of failure. Unlike the asphalt deadeners, these mats did not liquefy at any temperature. They softened significantly at high temperatures, but when they broke away from the mounting surface, the adhesive was still coherent, sticking in roughly equal parts to the substrate and their own aluminum foil layer. This is the same way the Dynamat Xtreme ultimately failed - albeit at a significantly higher temperature.
All of the asphalt mats failed at almost the same point. Both eDead mats, FatMat, Brown Bread and B-Quiet Extreme all melted. The asphalt ran out into a black puddle of goo and the foil fell down. None of them could survive several hours at 160ºF. The Dynamat Original failed differently than the aluminum foil skinned mats. It actually does have a PSA layer that held it in place longer than the others. It never melted, but instead cooked into a brown crumbly thing, but really, who cares? Dynamat Original may have been the bees knees back when people used that phrase, but its day is past. It is expensive and by Dynamic Controls own highly suspect performance testing, doesn't perform worth a damn.
The Cascade VB2 is a completely different composition than the other mats. It held up very well, but I only included it in this showdown out of curiosity. Cascade has contacted me and will be sending samples of their butyl damping mat for future testing.