Whats the best sound deadening???

[steve lan]

Hey guys.. I'm trying to reduce a little bit of road noise in my mx32 cressida . I was thinking of some under lay for the carpet and maybe something for the inside of the doors . What have you found to be the best ? Any infomation would be great . Thanks Steve

[DLA11D]

Dynamat.
Weighs a tonne, though.
I found you can buy it cheaper in US (ebay) and ship it over

[steve lan]

Yeah . Thats what a couple of people have said . I might just have to bite the bullet and pay for the good stuff!!!

[ViPeR_NiPPleX]

What would one expect to pay for dynamat? Is it sticky backed or do you have to glue it down??

[NORBY]

sticky backed, look on ebay us for it (its about $30 cheaper)

["Z" UTE]

Your local panel/paint supply shop will stock a sound deadening sheet. About 350mmx350mm square and about 4-5mm thick, self adhesive backing. It is a bitumous type product. I generally throw a half sheet into the door of each TA22 Celica I biuld, the doors then give that nice solid thunk when closed.

I believe it is called sound deadening/anti drumming.

cheers Chuck.

[Rob KE25]

2 steps I have used, to work together.

1.
I've used the same stuff ChuckLandwehr is talking about. It's like dynamat, but roughly half the price, and without the thin aluminium layer. That stops the drumming or 'tin sheet' sounds. Stops the sounds being carried along the metal, like a tin sheet.

2.
Then I have bought some sound deading foam from a foam/rubber distributor, which has aluminum sheeting on one side, adn I think open cell for most of its thickness. This is to reduce the dB by 'capturing' the noise, and absorbing the energy thoughout the foam. Comes in 5mm -25mm thick. 25mm thick is about $20 a metre. So not cheap. but seems to work well.



Don't forget to make sure all holes in the firewall are plugged up properly, and door channels, window seals have good seals in them. I haven't used it, but a few guys have said underbonnet sound deadening has greatly reduced motor noise.

Cheers, Rob.

[ViPeR_NiPPleX]

so which material would be best for which part of the car?

[Rob KE25]

Not claiming to be an expert on it, but any sheet metal (especially big long sections without bracing) I put alot of the tacky bitumous type stuff on. this was stop stop 'the metal wobbling and reverberating. Eg roof, door skins, rear quater panels. When I put it on, and then gave it a good knock with my knuckles to test the sound, it made heaps of difference- the sound stoppedd imedialtely. Not as much difference on the bumpy reinforced floor plan, but I still put it there to reduce undercarridge noise. A mates AE86 had the tacks stuff all over the firewall too, thicker than on the floor. So I did the same.

I would personally put both on everywhere, thick on the firewall(25mm) , and use a thinner (10mm) foam under the carpet and in the doors.

I put the foam and tacky stuff between the rear seat and the tank, and that greatly reduced the 2 fuel pump noises in the tank and diff noise.

The whole area doesn't need to be covered with the tacky stuff- it is to just stop the noise
traveling up and down metal.

[Sigmeister]

As stated, Dynamat is probably your best bet if you can afford it. Look at buying a bulk pack or two for the best value for money.

If you're a tight arse, you can get flashtac from Bunnings for much cheaper and does basically the same job. Its just not as heavy per m^2 as Dynamat.

There are also paint on deadeners. The wheel well\underbody paint is good for that, but it stinks so i wouldn't use it on the inside of the car. There was a product called G-Spot sound deadening paint. It was grey and basically had no smell, was great for some interior panels that were difficult to cut sheets of dynamat for. 1L was about $40.

[JZA70 R]

jaycar sell a dynamat knock off product too. alloy backed tar mat stuff.

dunno if its what your after but you can also buy cans of spray on underbody stuff from auto stores.

[RiceburnaGTV]

Clark rubber mate,I did my 22 for about $130 all up



stuffed a shitload in the back seat aswell!

[ViPeR_NiPPleX]

whaddya call that stuff?

edit: and does it work?

[oldcorollas]

i've even used camping mat foam once a couple of layers of that works well

but echo RobKE25.. you want to add weight to thin panels (to decrease their frequency?) and then foam to absorb transmitted sound...

migth be worth thinking about the flammability if tou will do any welding or put it in engine bay

for the small weight penalty, i have no idea why people rip out sound deadening material..

[steve lan]

Thanks heaps for the advise!!!!!! Looks like a have a very busy weekend in front of me!!!