Just got back from sound deadening. My main goal was efficient and effective "blocking" of exhuast noise both entering the trunk and noises entering the cabin from the trunk. I enlisted a knowledgeable local, Slade, to help me out. The main issues for subaru's is a porous rear deck behind the rear seats. Covered the holes with Dynamat, added a layer of closed cell foam, and then a layer of mass loaded vinyl over the rear deck. Closed off a port near the exhaust that was a direct entrance for any and all external sounds entering the trunk. Also added a tile of Dynamat to the center of each door to reduce any vibration and reverberation from the door skins. Very minimal stuff, total weight added was maybe ~10lbs or less. Difference? Substantial. Its not like i went from a tin box to a Merc, its still a subaru, but the internal exhaust noise and drone has dropped by an easily recognizable level. It was VERY cool to take the car on the first drive and immediately notice a difference just pulling out of the drive way. Slade is def a cool guy, thanks again for helping me out dood. Ill have to take you up on the Guiness if i ever catch up with you again before you head out. A+
My car is loud, which I like, but it would be nice to dampen the sound inside the car more. Do you have a round about figure of how much all the stuff costs? Also, was it just the rear deck and doors?
Hey, no worries man, glad I could help. Sorry it took so long to squeeze into the schedule. Material is ~$50 give or take..... I'm officially out of MLV, but will always recommend Don at http://www.sounddeadenershowdown.com for anything sound control related. Just make sure to define what noise you want to control as each product has a given purpose for which it is intended.
I would love for someone to do decibel meter testing and prove this so we can see exactly how much difference it makes.
There's a significant difference beyond the placebo effect even with minimal deadening. It is definitely worth your consideration IMO.