Lightweight sound deadening insulation.

[LeakySeals]

Wondering what options there are for lightweight vehicle sound deadening insulation. Something lighter than Kilmat or Dynamat I can use in the doors, trunk, wheel wells, etc.

 

[gathermewool]

No such thing as a light deadener. Deadener, by nature, is mass driven; the more the better. That doesn’t mean you can’t be strategic about if you’re trying to minimize weight add. Focus on large flat surfaces for the best bang for your buck.

I had an older Dynamat kit that I used while I was upgrading my speakers in the Legacy. The results is a mild reduction in certain road frequencies, whatever the door shells were vibrating at. Make sure to buy a nice roller to ensure proper adherence. If it’s bot sticking it’s not deadening.

With that said, I used only 3/4 of a two-door Dynamat kit in all four doors. Unlike the pictures of completely covered doors you see online, all you need is to deaden the large outer shell mostly. If I ever build up the courage to pull the headliner I‘ll use the rest of my Dynamat kit on the roof.

If you add foam, make sure it’s closed-fell to prevent moisture intrusion and mold buildup. If you add vinyl it needs to be relatively air-tight, otherwise you get the cracked-open-door effect.

 

[fsdork]

Apparently Dynamat has a "SuperLite" line that is 30% lighter than the standard product. Not sure if that is the difference you are after. I would imagine they have landed on a certain thickness/weight for a reason. If you go too light, it probably can't do its job.

http://www.dynamat.com/automotive-and-transportation/car-audio/superlite/

 

[fsdork]

No such thing. Deadener, by nature, is mass driven. Isolation via foam a d vinyl are also effective, but will not deaden. With that said, I used 3/4 of a two-door Dynamat kit in all four doors. Unlike the pictures of completely covered doors you see online, all you need is to deaden the large outer shell mostly.

I had an older kit that I used while I was upgrading my speakers in the Legacy. The results is a mild reduction in certain road frequencies, whatever the door shells were vibrating at.

If you add foam, make sure it’s closed-fell to prevent moisture intrusion and mold buildup. If you add vinyl it needs to be relatively air-tight, otherwise you get the cracked-open-door effect.

This is a good point too. I recall during my days of selling car audio about 20 years ago (wow), one of the demos the Dynamat reps used was a relatively small piece of Dynamat stuck to a piece of metal (brass, I think). Compared to a similar piece of metal with no Dynamat applied, it was far "deader" in the sense that it wouldn't ring when struck against a hard surface.

 

[gathermewool]

This is a good point too. I recall during my days of selling car audio about 20 years ago (wow), one of the demos the Dynamat reps used was a relatively small piece of Dynamat stuck to a piece of metal (brass, I think). Compared to a similar piece of metal with no Dynamat applied, it was far "deader" in the sense that it wouldn't ring when struck against a hard surface.

Yep. Got me before the edit. Added a little more info. Note: I’m no expert, I just wanted the same as the OP: add as little weight as possible for a small decrease in NVH. I think my doors were a good start.

Also remember that the effect is cumulative. There are a lot of things vibrating at different harmonics, which means you may not achieve your goal just by deadening the doors. Areas like the roof make tons of noise, especially when it rains. My previous Focus was deafening in the rain. My Legacy and Forester likely have something up there, since they’re not nearly as loud.

 

[GoldDot40]

I used Noico and Kilmat in the floors of my Camaro when I restored it. They are both very similar in material and may even be the same product with different labels.

36 sq ft weighs right at 27.6lbs....that was a near perfect coverage for my 1979 Camaro for the entire floor. The product is great and works exactly as advertised.

 

[4WD]

Wondering what options there are for lightweight vehicle sound deadening insulation. Something lighter than Kilmat or Dynamat I can use in the doors, trunk, wheel wells, etc.

You can augment the minimum use of of Dynamat by applying 3M CCF over it …
That product is also a scissor cut peel and stick.

 

[Luftmasse]

I use hushmats.

But if your goal is to reduce noise, this is not gonna help. You will need to add mass if you want noise reduction..