Heat and sound deadening material

I put in a bunch of that aluminum bubble wrap heat sheild stuff in my 73 behind the interior panels and under the carpet when I did my wiring. It was cheap. I got a big roll of it from Lowes for 20 bucks. More than enough to do my big girl.

I like um big...BIG!!!
 
If you look at some of the car audio forums, there's a lot of support for Damplifier and Damplifier pro. If you don't want that, the consensus is that butyl mats are much better and less smelly than their asphalt counterparts. I can't personally attest to their claims, though.
 
Damplifier pro is what I will be using. It is cheaper and better IMHO they also sell some led shielding if you need that extra quiet. I know it adds on alot of weight but what is better than driving a 700HP street car on turn downs and being able to talk on the cell phone or listen to the radio while going down the road?
 
Interesting. I went to the damplifier website and they have some of the goop type sound deadener. I wonder how this stuff compairs to POR15. The blurb on the website says that it is also great to prevent rust and usable as an under carrage coating. Considering its 1/2 the price of POR15 for 5 gallons I wonder if it is almost the same stuff sold to a different market or maybe achives almost the same effect ?