Well guys, i finally got tired of not having any sound deadenin at all in my truck. So I went over to Lowes and got 2 roles of the "mythical" Peel and Seal.
This stuff is really surprizing me...lol Its 40mil thick and sticks pretty darn good (the roles are 6" x 25'). So far i have used one role on the back wall of my truck and bout 1/2 of one on my passenger side door.
I took my sub out so i cant say if it helped the bad rattles much, but the mid-bass response in my "deadened" door is MUCH better than in my nondeadened door. I'm gonna get on the termlab later on (after i fininsh deadenin the whole truck) and see if it helped my SPL any.
All and all...it seems like this peel and seal stuff is the real deal.
I too am planning on picking some of it up to deaden my doors. I am sick of letting my DLS Iridium mid go to waste because that thing can really pund for a 6.5. Plus my door vibrates a little too much for me because i get annoyed easily.
sound deadening will improve efficiency because you're not losing as much energy to rattling metal in the car, and it'll lower the sympathetic frequency of the vehicle as a result as well.. but it probably isn't going to give any drastic SPL improvements. Essentially it just helps improve the listening environment.
Did you use a heatgun or other source to warm it up properly before you applied it? If you don't do it right the first time, it will eventually start to peel back off. (I know, I had the same problem.)
the cheaper stuff needs to have surfaces cleaned well and heated before applying it. the other thing is that with the cheap stuff I don't leave it exposed. it's usually sanwiched between plastic panels and sheet metal so it's held in place that way.. not just stuck on and hope it stays
hmm should invest in a heat gun ive needed one on several occasions.. i was gonna put those strips everywhere and spray rubberized undercoating all over it so it would be stuck there.. try that this week sometime