Cabin noise

Originally Posted by Dwight Frye

I have thought about this: there is a stretch of freeway that I travel that has various surfaces and really plays a symphony, or rather cacophony with the tires. The thing to do would be to use a recording measuring device and travel a certain section of road, long enough to get a good reading. Maybe 10 miles. Stay in one lane, at one speed as much as possible, A/C and stereo off & windows up. Take a measurement maybe every 10 seconds with the microphone in a fixed location, like attached to the inside driver side headrest strut. Install the Dynamat & repeat the test. Print out the graphs or plots and look at the difference in SPL at the same locations and elapsed time. There you go.

Originally Posted by Cheech

There's an app for that!!

Did exactly what you mentioned. After installing the sound deadening liner in the rear hatch the level of noise in the cabin dropped 10db (using the iphone, same stretch of road, same speed, dry road.