Where to start with sound insulation.

[Romz]

I know the topic of sound deadening/insulation/proofing has been tackled before, but what I want to know is where to start? I have some 3M body deadener from SCA http://media.supercheapauto.com.au/sca/ ... 220408.jpg
I was gonna use this in the wheel wells, (on the outside of the car). And then I'm not sure if I should concentrate on the doors or the floor.
All I want to do is kill some of the road noise, I've only got the stock ES stereo. If I was gonna do the doors I'm gonna use dynamat (surprisingly cheap a Ryda compared to Ebay), but on the floors I was gonnna use Jaycar AX3662.
I figure using the expensive stuff on the doors is better as it'll adhere more effectively.
What do you guys think? Where should I start? Anyone ever used the 3M body deadener?

[tadz0rz]

Yeah put that stuff on the wheel wells and depending on what you have access to, try to put it under the boot floor pan and that sort of area. Obviously the more deadener you have the better so anywhere outside of the car that hasnt got body deadener on it, slap it on.

I was able to stretch half a bulk pack of dynamat to do my boot floor and sidewalls. Defintly do the boot and under the back seat, then you would probably need another bulk pack to get through all 4 doors.

You can do the floor pan aswell if you like, but its probably a bit overkill considering I just did my boot and the road noise in my car dropped considerably

[Romz]

so you're suggesting I concentrate in the boot area, and the rear of the car in general? Makes sense, it is just a hollow compartment. I work in a ship, so I know all about noise in hollow metal compartments.

[scraverX]

I have my front doors layered with dynamat. Inner and outer skin and only some in the sides of my boot (none on the floor).

I can say for certain that most of my road noise comes from the back of the car so Tadz is probably correct in saying that doing his boot floor made a lot of difference.

It's also worth noting that the heat shield under the rear of the car (underside of the boot above the muffler) rattles like a bastard.

[bunnishiwa]

Depends on your budget really - if you seriously want to reduce the cabin roar (I've a MY08, so know all about it), try Dynapad (approx $188 for both front foot wells) - this is where most of the noise comes from. doing the boot in Dynamat, although improving the sound of my Bass, did not reduce road noise. If Dynapad is too expensive try the .5" Dynaliner, which is approx $130 for the same area.

For the doors use Dynaliner .25" - I would use this over Dynamat style products if you've no intention of replacing the stock speakers/stereo.

On a side note, can you post once you've done the wheel-arches in the 3M stuff, as I've been considering doing that

[Romz]

i just checked out the description of dynaliner on Ryda website; "This durable crush and tear resistant material has the highest heat blocking properties available in a single layer synthetic foam-type material.
Dynaliner isn’t affected by oil and does not absorb water. Dynaliner provides acoustic isolation and excellent thermal insulation for roof, firewall, floor, quarter panels, doors and even as a hoodliner."

And then the description of this jaycar stuff product No.AX-3687; "This durable crush and tear- resistant material has the highest heat blocking properties available in a single layer synthetic foam-type material. Not affected by oil and does not absorb water. It provides acoustic isolation and excellent thermal insulation for roof, firewall, floor, quarter panels, doors and even as an under bonnet liner.

Hmm... can't help thinking there's a bit of plagiarism going on here.
Who should I believe.

[bunnishiwa]

Dynamat is one of the 2 best products on the market - I couldn't comment on how good the Jaycar stuff is in comparison, but am personally a believer that if you're gonna strip the inside of your car for a day or two, then the primo product is what I'll be putting in, baring opinions from anyone who has installed anything else of course

[Romz]

Anyway, I finally finished the wheel wells, and to be honest, I wasn't really inpressed. I'm becoming a little obsessed with the road noise that occurs going down the M4. I live around the concord exit, and once or twice a week (sometimes even more) I have to drive all the way to Mt Druitt, and the noise is just giving me the sh!ts something fierce.
I did hear a difference on slower roads, but once you hit about 80 then there's no real difference. I'm gonna start on the interior now.
Has anyone ever layed any sound deadener under the cabin floor? if so, how do you go about ripping out the carpet? is there a formula to it or is it just a hack job? Anything I should look out for?