• Introduction
• Why Do It?
• Should You?
• How To
• Asphalt vs. Butyl
• Product Specs
• Temperature Tests
• Adhesion Test
• Price Comparison
• Conclusions
• Contact Me

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,

Introduction

This site is my attempt to sort through the world of automotive sound deadening products. When I first encountered the process, I found it very difficult and confusing to gather enough objective information to make an informed decision.

Add in the marketing hype and snake oil and even after a great deal of research, I still didn't know if I should do it and if so, which products were best suited to the task. I ended up just diving in and was lucky enough to have a good outcome. Other people haven't been as fortunate. I hope this will make the process easier.

Prevent alien mind control while driving!
Well to be honest, that's one of the few outlandish claims I haven't seen made for these products. When the actual benefits are so outstanding, it is completely beyond me why anyone sees the need to resort to crazy exagerations.

There are two general classes of deadening/damping products. Liquid deadeners can be sprayed, brushed or applied by trowel, depending on formulation. In most cases, these take some considerable time to apply. They require several layers, with curing time between applications. Since I don't have a garage and need to use my car every day, liquid products didn't seem like a good choice for me.

The second and most popular group of products are the self adhesive mats - generally a thin layer of rubberized asphalt and/or Butyl compound with a constraining layer of aluminum foil on the exposed side and release paper protecting the adhesive before installation. These are the products I will try to evaluate through a few basic tests and some observations.

There really seems to be more false and misleading information than reliable facts in this product area and I will do my best to cut through the mess. Product failure can have significant negative consequences. I want to help you avoid that.

There are a few basic questions I hope to help you resolve. Is sound deadening worth the cost and effort? Which product will best suit your needs? How far should you take this?

In the world of automotive acoustic enhancement there is a product whose name is synonymous with the entire category. Much as Kleenex is used to describe all facial tissues, Dynamat, manufactured by Dynamic Control of North America, Incorporated in Hamilton, Ohio is the de facto standard. It is a high quality product with tremendous name recognition and the Dynamat Xtreme product was the pioneer in the Butyl based sound damping field.

The main problem with Dynamat Xtreme for many people is the cost. If you only need two square feet for your speakers, you won't even notice the price. If you are planning a full vehicle installation, as I did, you may see your cost rising into the thousands of dollars, just for this first step. This situation has created an opening for many competing products. Some compete solely on price, some address a specific need that Dynamat Xtreme may not meet, but there are currently a dozen or more products available, specifically sold for automotive use. There are also many products designed for other purposes that people have used.

I have seen enthusiastic recommendations for every manufacturer's product as well as various materials designed for other purposes - from tar paper to pouring concrete into car doors.

When I hit the price wall, I investigated as many alternatives as I could find. I looked carefully at the roofing products before rejecting them out of concern for their durability in a car parked in the sun all day during hot and humid Maryland summers. This is when I ran into the lack of useful comparative information available.

There are plenty of recommendations out there but I found it difficult to determine which were based on solid reasoning and which had a less useful motivation. There really aren't a lot of people with significant experience with a range of products. The products change often. If you buy them for your own use, that will probably be only once every few years. If you are a professional installer, you are probably locked into one product. This isn't like speakers that you can change on a whim. If it works, it is there for good.

To try to bridge this information gap I decided to gather as many samples of different products as I could, put them through some basic but repeatable tests and compare the results for the benefit of those of you trying to make an informed decision.

This is not laboratory level testing. I make no claims of precision at all. I also made no attempt to determine the relative effectiveness of the products when properly installed. Since the basic function of these products is to:

• Add mass to panels to move resonance out of the audible range
• Reduce vibration through viscoelastic damping
• Reinforce panels to prevent flexing when subjected to sound pressure
• Act as a barrier to the transmission of unwanted sound (noise)

It is most important to determine which products can be reliably installed and will be durable enough to last a long time. Failure in these areas can have really serious and difficult to correct consequences. After that, we can try to figure out which materials are most effective.

Finally, I've thrown in some photographs, specifications and pricing comparisons.