Defining Some Terms

Before we can get anywhere, we need to make sure we are talking about the same things. "Sound Deadener" is a vague term that describes a range of materials and techniques. It has traditionally been used when referring to vibration dampers - a specific class of products designed to control resonance in panels. I'll be referring to these products as vibration dampers.

When it comes to noise control we are concerned with engine, exhaust, tire in contact with road surface, and wind from entering our vehicle and from all of the other vehicles around us on the road. We may also be concerned with noise created by the music we play as it interacts with the vehicle around us. Some of the noise is transmitted directly through the structure of the car. Some of it travels through the air before it passes through the vehicle panels and glass on its way to our ears, often times exciting panel resonance that creates a secondary noise source.

The first step in any successful noise control or acoustic improvement project is minimizing panel resonance. It doesn;t really matter if the existing resonance is caused by the vibrations directly introduced by the engine, exhaust and suspension or if it is being driven by airborne sound. Resonating panels are important routes for transmitting and reinforcing noise.

Everything we are trying to do comes down to sound. Whether we are trying to quiet a vehicle, improve its ability to host a music system or both, it's all about sound and controlling what reaches our ears. Sound is almost devious in its behavior so we need to understand a little bit about how it moves around before we can control it. 


This is where vibration dampers come in. Your vehicle most likely came from the factory with at least some vibration damper applied. Unless yours is a luxury vehicle, or even if it is and you have added an aftermarket sound system that takes the vehicle beyond the original design specifications, you will want to add more vibration damper. OEM applications favor reducing weight and cutting cost beyond all else. In our adjective to quiet our vehicles, many of us took this too far in the opposite direction - applying multiple layers of vibration damper to every bit of sheet metal in the vehicle. I'll tell you something that no one else selling vibration dampers will - this is wasteful and counter-productive. Put images of shiny silver vehicle interiors out of your mind. When it comes to vibration dampers, anything more than 25% coverage is excessive. Beyond that, you are wasting time and money, making it difficult to refit trim panels and potentially making the vehicle more difficult to service in the future - you are using the wrong tool for the job.