This "noise" is caused by vibrations...
Vibrations are the rapid, repetitive sounds often associated with the object that is creating them.
Two types of vibrations are present. Airborne, and mechanical. (Either the vibration can be MADE by the equipment, or the vibrations can strike equipment, and then cause THAT object to move)
The ways to control it, are either thick, heavy meaterials (lead being the best, but also the heaviest and most dangerous) that will stop the materials from begining a vibrations,,
Or using light, celled materials to absorb and disperse the vibrations (muffling...)
By far the best of the two is to stop the problem before it becomes a problem.. The best product on the market is, IMHO ;-), Dynamat.
The offenders of road noise, in order of importance, are:
Floor (undercarriage)
Firewall
Outer-door sheet metal
Inner-door panels
trunk bottom
trunk lid
roof
Applying to most important areas first will help. As little as a 25% coverage are can decrease ambient noise by as much as 75%.
Doubling the layers can add a 300% decrease...
Start with the most easily accesible and most annoying areas, first.. then, as you upgrade (or get time) apply to the smaller, harder to reach areas..
Hope this helps..
Ray
(Dynamat Rep..)
S_R_Haralson@sar.med.navy.mil
