update Re: Insulation sound deadening

From : midlant

Q: thanks all. mcmaster-carr has a well known mat that is like the original dynamat but far cheaper. the panels do need to be dampened with a heavy material to keep from vibrating. an absorber of some sort must also be used. price is a point with me as im not employed. i do have some income coming in but only enough to pay utilities bills and the like so price point is imperative. wnats dont outway needs. what i found that is working pretty well is duct insulation from the box stores. its a self-adhesive foam with foil covering. it has some weight so dampens and since its visceilastic foam its an absorbant as well. i drove around today with the interior still out drivers seat only as i took the headliner in to get recovered. roof rear cab and rear side walls are treated with 2 rolls of this tuff. i also shoved a one foot peice of standard home insulation in the cavites on each side. its quiet! still a lot of noise coming on from the door panels and floor by comparison. i want to get some more stuff up under the light weight foam the factory uses under the dash. when the carpet goes back in along with the seats and headliner it should be that much quieter. its amazing how loud the truck is with the interior out. they use it as sound deadening vice just a seat to sit on. there is nothing behind the rear seat. there is a factory applied something hard to the floor in spots as well as the side panels. 4 inch squares or odd shaped sizes here and there in no particular order i called a local industrial supply place looking for closed cell rubber or neoprene and when asked what i wanted it for the man said go get the diy bedliner. he used it on his jeep and was quite happy with the outcome. i read a post on a car forum site where a man had mixed concrete patch with the liquid roof repair stuff with great results. just something i read. i talked to a local shop. their experience has been regular dynomat doesnt do much but the extreme which is visceolastic foam works well. since the factory already has dampening taken care of im looking for absorbtion material; heavy dense closed cell foam of the type normally used in audio apps. the duct insulation seems to be the ticket for my price range $14 for a 1 x 15 ft roll; doesnt go far. there is an ebayer selling 1/4 closed cell neoprene in ca for pretty cheap. its $25 for a full sheet 42 x 72 inches. i could place that on the floor but it might take up too much room and the carpeting not fit back into place. i may add the duct insulation in spots as well as stop by a carpet shop for a pad. im going to get the foam up under the factors foam as far as i can. im not removing the dash toget behind it thats for sure. lol blessings john .