Mass Loaded Vinyl

[what_the]

I have been reading and have learned that the mlv is the product for sound blocking. I know the more mass, the more sound blocked. My question is how much of a difference will there be form .5lb/sqft vs 1lb/sqft mlv. I would like to keep the added weight to my vehicle down, but I don't want to sacrifice to much of my interior silence. Here are the example products:

1/16" soundproofing material Mass Loaded Vinyl (1/2lb/sqft)

Mass loaded vinyl barrier Wholesale 1/8" Soundproofing (1lb/sqft)

Also how necessary is the foam decoupling layer between the panel and the mass loaded vinyl? If i can cut it and save some money, that would be great.

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[Anthony Collova 10+ year member]

The foam barrier on the MLV is used to decouple the vinyl from the panel it is laying upon.

There is some debate as to exatly why different materials work better than others for decoupling, but what is agreedupon is the need to decouple the vinyl.

Close cell foam, open celled foam, Jute, bubble wrap, all work well, but some will hold up in automotive conditions better than others.

Go for something that is at least 1 lb per sq foot, and adecoupler that is at least 1/8 inch thick. As long as the vinyl is elevated off the panel you will be good.

ANT

 

[cartablanca 10+ year member]

bubble wrap? really

 

[what_the]

Okay cool thanks. And yeah the notion of a decoupler makes sense from the handful or acoustics/vibrations classes I took at GT. I was more unsure about the mass of the vinyl, so thanks for clearing that up.

And yes bubble wrap would theoretically work. The only point of the decoupling layer is to prevent transmission of vibrations from the panel to the vinyl. So any material that absorbs vibration would work.

 

[I Like Waffle]

Its all over ebay for cheap, check it out. Walmart sells MLV mats for camping too.

 

[bhsdriller 10+ year member]

so what about some kind of dynamat layer between the mlv and panel as a decoupler

 

[Anthony Collova 10+ year member]

Nope.. that would be a total waste.

Dynamat works by connecting directly to the sheet metal and reduces vibrations.

Applying it anywhere other than on the metal will be a huge waste of money and time.

Hope that helps!

ANT

 

[Rudy 10+ year member]

Every time you double the mass of a barrier or the frequency of the sound you are blocking, you'll gain 6 dB - under ideal conditions. You can probably expect 3 dB in a car. The important thing is that you aren't starting at zero - the vehicle's sheet metal has mass and you are adding to what you start with. 1 lb/ft² does seem to be the sweet spot. 2 lb/ft² MLV is 1/4" thick and is pretty difficult to work with. It's always going to be a trade off between the mass you add and the results you get. Instead of using a lighter barrier, you'll probably get a better return on the weight you add by carefully targeting the areas you treat.