How much Dynamat?

[RobertK]

How much Dynamat (in square footage) would you guys estimate I would need to line the inside floor of my 4dr 325i and the trunk?

[Van Westervelt]

are you goin to be doing under the rear seat and sides in the trunk or just the floors?

[Van Westervelt]

40-50 just for the floors. I did the wells and quarters, kicks, and doors. i have used about 75

[RobertK]

75 squre feet for all that? What about the trunk?

I plan on covering as much as possible.

BTW.. Where did you order yours from and how much did you pay for it?

[Van Westervelt]

well, i used the bulk packs... 36 sq ft per box. Used up 2 of them, and I need a little more. I did full trunk, less the boot lid. Inside rear quarters and wheels wells, and both front doors and kick panels. And under the rear seat and the wall only on the inside. I still need to do the floor. I am waiting for a few more bits and peices as I am also putting the extreme liner (the led sheet) down in the floorboards as well in place of old factory crap. I can post some shots later if you want me to.

Oh yeah, from the 2 original boxed, i still have 2 sheets left. But that wont be enough for my floor. I also did my license plate :)

[rs4pro3]

A friends dad told me about some roofing material that is basically just like dynamat, it's got a sticky back to it and a reflective surface like dynamat but costs way less then the real deal. He covered there complete van with it, and he was trying to get me to do my 85 318i when I was putting in a stereo. He told me he just picked up at home depot etc.. so it might not hurt to take a look. A friend here is doing the same thing, but the stuff he is ussing is supper light weight, it's some sort of high density plastic filled with air, with a sticky back. He did his jeep and said it greatly decreased road noise.

[Van Westervelt]

A friends dad told me about some roofing material that is basically just like dynamat, it's got a sticky back to it and a reflective surface like dynamat but costs way less then the real deal. He covered there complete van with it, and he was trying to get me to do my 85 318i when I was putting in a stereo. He told me he just picked up at home depot etc.. so it might not hurt to take a look. A friend here is doing the same thing, but the stuff he is ussing is supper light weight, it's some sort of high density plastic filled with air, with a sticky back. He did his jeep and said it greatly decreased road noise.

The roofing stuff has virtually no effect. Tried some when I worked there.

What is the brand of stuff your friend used on his jeep? Lightweight sound deadening, havent heard the two used synonymously.

[RobertK]

The roofing stuff has virtually no effect. Tried some when I worked there.

What is the brand of stuff your friend used on his jeep? Lightweight sound deadening, havent heard the two used synonymously.

I'm interested in that as well..

Usually density is required to absorb sound and vibrations so a lightweight alternative would be interesting to see.

[PiercedE30]

with the 75sq ft bulk pack, you can do a FULL two trunks and pretty much entire interior with some left over.

[ptownTSI]

get RAAMmat from Rick McCallum www.raamaudio.com i used it in my jeep and my girlfriends jeep. not quite as good as dynamat extreme, but its $100 for 66 square feet. compared to $300 for 36 sq ft of dynamat extreme. its still really good stuff though.

[AndrewBird]

A bunch of MG guys us ehte roof stuff with great success. It can be bought at Home Depot for cheap too.

Others use some stuff from McMaster-Carr - Part# 9709T19

Here is a pretty good comparison of some of the major brands of sound dedening:

http://www.sounddeadenershowdown.com/

[StereoInstaller1]

Here is a pretty good comparison of some of the major brands of sound dedening:

http://www.sounddeadenershowdown.com/

Wow...TERRIFIC site, Thanks.

If I were to offer advice on Dynamatting (which I just fucking HATE...horrid work) I would say this:

Take the car apart. Tap (like knocking on a door) each panel of the car in a systematic way, looking to find the noisiest areas. Apply a small piece of the butyl-type of mat to the noisiest areas. Tap again!

I use a combination of Dynamat Extreme and carefully shaped pieces of MDF to achieve noise control. Dynamat clamped between a chunk of MDF and the sheetmetal works wonders, let me tell you.

Another thing I recommend is Urethane, the windshield adhesive. If you look at how a body panel is made, you will see it is a skin of metal, glued sparingly over a frame (skeleton?) of stamped sheet metal.

If you look at how those panels are glued, you will see just a few dots of glue, ususally every foot or so. If you inject urethane into those cracks and let it dry, you will hear a HUGE difference in your tapping tests, and more difference on the road. If you then cover this area with something like Dynamat extreme, that is as good as you are gonna get.

Slapping the roof of a car before and after I do this treatment goes from a loud "POING" to a solid "Thunk".

In reading that site, I feel the one area that should have been addressed better is the quality of the installation is of huge importance. The area MUST be very clean, dry, grease free. You must apply huge pressure to every square inch of mat if you are aiming for a noise free car.

Good Luck!

Luke