Sound Deadening

[CrazyKenKid 64]

tonight I was able to deaden 3layers on my rear deck and 2 layers on the rear seat (where the seat sites) and 2 layers in the trunk itself.

now my question is since i am nearly 100% sure i only have enough deadener to completely deaden one thing, which thing should i deaden first?

either the back doors and the trunk lid or the roof? which would be of more benefit and why?

see i want to get 1 good layer of deadener on the roof and then a second layer if i have enough left over BUT if i do the back doors 3lay thick or 2layers and the trunk lid i know i will not have enough left to do the room

my car is a 95 grand am the sub and port is firing forward into the cabin and the rear seats fold down. i know with the rear doors wide open i barely break 125db but when they are shut i hit about 145db

so i am thinking i should do the doors and trunk lid and then order some more for the roof or should i do this the other way around?

please let me know what you guys thing and thanks for your time

Kenneth

[Duran 387]

Is the trunk sealed? If so don't deaden the trunk lid, if not get the trunk lid.

[CrazyKenKid 64]

umm good point didn't' think of that!

no it isn't sealed off yet i am going to wait until i get a setup i am happy with then i will seal it all off with fiber glass or something

so roof it is then! unless someone else has some input!

thanks

[Second Skin 120]

the best place to deaden at the start is always the doors. the vibrations from the road come up the tires, through the frame, and then bounce around in the doors, so that's the best place to deaden whenever you start a new project, for future reference. if you havent yet done all of the doors do those first. after that you should focus on the rest of the car, as the rest is more or less effected the same amount by the vibrations that run through the car. except the roof. that's usualy the least effected of all the areas in the car.

AX

[BanginGMC 23]

"Some of you know that I have been testing and writing about products like these for more than four years. Here’s what I’ve learned in a nutshell: To control panel resonance you should use the best vibration damper you can find and only treat the 25% at the center of the panel. You won’t have to worry about asphalt melting or falling off and you won’t get black goo from cheap butyl compounds on your living room carpet. You will spend less, the project will be easier and the results will be better." - SDS

[///M5 2,833]

Yep, multiple layers are a waste. You've WAY exceeded the law of diminishing returns. Hit the center of the resonant panel...

[CrazyKenKid 64]

o wow i guess i did waste some time and money i guess the only positive is it cost me 100$ for 50ft.... damn o well thanks for the input

o well lesson learned.

thanks M5, SDS, and AX for your valuable inputs

so i might as well share some pics of my rear doors which i just did 1 layer of.

other then that thanks again guys and I will keep this in mind for the next build I do and i will post some pics of the rear deck and back seat once i pull this setup out to install my 2-12's

o and the front doors have already been done I just don't have pics of them.

[CrazyKenKid 64]

another one lol

[Kanaworm$ 292]

What brand of dampener is that that you used?

[CrazyKenKid 64]

it is called B-quite extreme

http://www.b-quiet.com/extreme.html

[BanginGMC 23]

Multiple layers isn't a waste if you want to stop flex. I used roughly 7 layers on Second Skin just on my roof.

[CrazyKenKid 64]

holy deadener batman lol! it sure looks pretty... expensive?

[Duran 387]

holy deadener batman lol! it sure looks pretty... expensive?

Exactly, good bracing would have been cheaper and stronger.

[mdexxxiv 1]

GM roofs are known for flexing badly. Best to brace it with 4' strips of layered MDF with silicone to adhere it, then coat with the Damplifier Pro on the metal between the strips. That will give you the added rigidity.

[BanginGMC 23]

holy deadener batman lol! it sure looks pretty... expensive?

Not for me

holy deadener batman lol! it sure looks pretty... expensive?

Exactly, good bracing would have been cheaper and stronger.

Cheaper? Doubtful.. plus, i'm not going to weld anything on my roof or make any type of wood bracing.

[///M5 2,833]

you WILL cover it with a shitpile of futility,but won'tdo something that works? Nice