[ndm]

Okay folks, I was looking up some deadening stuff for the jeep. I have never used MLV before but am looking forward to the reduced noise that it is supposed to give me.

So I was allowing my brain to freely roam when a concept came up.

MLV- Most of it is rated at 1 pound per square foot right. It works by being a loose flexible material that is dense so therefore it blocks radiated noise. Many people find it hard to come by and some of the stuff stinks and is not flexible. It is around 1/8 inch thick so sometimes hard to squeeze behind panels.
I am not knocking it at all but just brainstorming.

So...

If its density and flexibility and the fact that it it decoupled from the surface is what makes it work so well, then what in theory would stop us from using something else that has the same qualities but is more readily available and more familiar to almost everyone in this hobby.

My theory is that I can simply order CLD (dynamat, second skin, SDS etc..) and adhere it with two layers (butyl adhered to butyl) and install it in the same manner as the mlv.

The reason why this concept has captivated my mind is because CLD is very flexible. It can have a similar density. Second skin Damplifier pro is .6lb/ft2 so two layers would be 1.2lb/ft2. The Kolossus kno knoise is 0.93lbs/ft2 so it would be almost 2lb/ft2 in two layers and could perhaps be used in 1 layer by adhering it directly to CCF.

I realize that this concept might not be as cheap as doing MLV but I am simply entertaining the idea that it could potentially be not only more effective that traditional mlv but also easier to use for instance under an area with tight confines since it can be squished down in the tighter areas. It could also be a more one stop shop type of product.

So to summarize-
1- Apply the CLD with about 25% coverage as you normally would.
2- measure out the size of the MLV layer that you normally would use but instead use two layers of CLD.
3- Use Closed Cell foam to decouple the double layer

In cases where the CLD is heavier like the kno knoise you could use one layer adhered directly to CCF.

Okay...go ahead and discuss...
Lets keep this topic on track and without any attitude.

 

[SkizeR]

try and get back to us with your findings

 

[ndm]

Well I was hoping for some discussion on the subject first. I respect the opinions of the forum members and am looking for someone to poke holes in my theory. If there are no holes that can be poked, I think we may be on to something.

 

[SkizeR]

i cant see it working. and on another note, itll be a) much more time consuming, b) very messy and sloppy, and c) it will probably be more expensive than traditional MLV

 

[ndm]

i cant see it working. and on another note, itll be a) much more time consuming, b) very messy and sloppy, and c) it will probably be more expensive than traditional MLV

More expensive...yes probably...
time consuming... I would not think by much. It would probably cut some time off in very curvy areas since mlv is not as conformable.
Messy/sloppy...yes the butyl could be more messy but working to keep it neat would mitigate some of the messiness. For instance,folding the foam over the edges of the cld or even folding the cld over itself.

Im not worried about extra work really. I am interested in the effectiveness mostly. In my head a loose layer of cld at 1.2lb/ft2 should be more effective than a single layer of mlv at 1lb/ft2 and be more conformable.

Awesome....lets keep the discussion going!

 

[SkizeR]

More expensive...yes probably...
time consuming... I would not think by much. It would probably cut some time off in very curvy areas since mlv is not as conformable.
Messy/sloppy...yes the butyl could be more messy but working to keep it neat would mitigate some of the messiness. For instance,folding the foam over the edges of the cld or even folding the cld over itself.

Im not worried about extra work really. I am interested in the effectiveness mostly. In my head a loose layer of cld at 1.2lb/ft2 should be more effective than a single layer of mlv at 1lb/ft2 and be more conformable.

Awesome....lets keep the discussion going!

im almost positive theres more to it than just weight

 

[ndm]

im almost positive theres more to it than just weight

from the sound deadener showdown site for mlv.....
"How inexpensively can we create a substitute for lead sheeting that will accomplish the same thing"?
Mass loaded vinyl is dense and limp - the ideal characteristics for a barrier. A material's resonant frequency is determined by its mass, stiffness and geometry. Low mass/high stiffness mean high resonant frequency. High mass and low stiffness mean a low resonant frequency. MLV and lead sheeting have resonant frequencies below the the audible range. Makes it an excellent barrier.



So I have established that it would probably not be as cheap as mlv but Im trying to really entertain the idea.

 

[TOOSTUBBORN2FAIL]

The biggest issue is that two layers of cld stuck to each other will be stiffer than a decent mlv, which will reduce effectiveness.

 

[Justin Zazzi]

im almost positive theres more to it than just weight

Nope, mass is all you need to act as a sound barrier.
This method would work, but it would be less flexible and more sticky (meaning harder to install), and more expensive.

Good try thinking outside the box though.

 

[ndm]

The biggest issue is that two layers of cld stuck to each other will be stiffer than a decent mlv, which will reduce effectiveness.

Hmm....very true...now how about a single layer of the heavier cld but with ccf on the butyl side. Wouldnt it be like the luxuryliner but more conformable?

 

[ndm]

Nope, mass is all you need to act as a sound barrier.
This method would work, but it would be less flexible and more sticky (meaning harder to install), and more expensive.

Good try thinking outside the box though.

Im a true outside of the box thinker. 90% of the time I am proud of that but sometimes I wish I could just color inside the lines like the rest of the kids.

 

[Justin Zazzi]

The biggest issue is that two layers of cld stuck to each other will be stiffer than a decent mlv, which will reduce effectiveness.

Can you please elaborate? I can see how a stiffer material would have a higher resonant frequency, but I don't see how it would be a less effective sound barrier.

 

[ndm]

Can you please elaborate? I can see how a stiffer material would have a higher resonant frequency, but I don't see how it would be a less effective sound barrier.

I would think that the lower stiffness with more mass would block better and absorb more sound.

 

[Alrojoca]

:snacks:



Maybe another 2 different options based on the same idea.


1. Make a sandwich, by sticking the CCF in between the 2 CLD layers


2. Stick the CCF to the bottom CLD layer after the double CLD layer.

Terminate edges with aluminum tape.

This will eliminate the mess and mistakes folding the CLD to have 2 aluminum sides, also to prevent mess, using aluminum tape to cover the edges and keep it from sticking all messy black stuff on any area it touches.

 

[ndm]

:snacks:



Maybe another 2 different options based on the same idea.


1. Make a sandwich, by sticking the CCF in between the 2 CLD layers


2. Stick the CCF to the bottom CLD layer after the double CLD layer.

Terminate edges with aluminum tape.

This will eliminate the mess and mistakes folding the CLD to have 2 aluminum sides, also to prevent mess, using aluminum tape to cover the edges and keep it from sticking all messy black stuff on any area it touches.

Yup...good creative possibilities. I have lots of aluminum tape.

 

[Alrojoca]

Yup...good creative possibilities. I have lots of aluminum tape.

Yes and I think the 2 layers facing Aluminum on both sides, I can I agree it will be stiffer not as flexible, by not being as flexible as MLV, there might be some air pockets in the door since it is not a flat surface. The air pockets will leak air and noise.

With either the sandwich or the 2 layers and the CCF at the bottom the flexibility issue may not be an issue since the CCF will sit better on the un even areas of the door. It would be much better with the CCF on the bottom and the 2 layers on the top (edited just added this last sentence)

Cost is the issue, I wonder if the cheapest CLD will be more cost effective with this idea


Still, cutting areas for cables and assemblies will still be messy and not easy, a good knife will be needed and gloves

 

[TOOSTUBBORN2FAIL]

Can you please elaborate? I can see how a stiffer material would have a higher resonant frequency, but I don't see how it would be a less effective sound barrier.

I was thinking because of the higher resonant frequency, but in thinking more, it would likely still be below being audible.. In fact, being stiffer might actually be better as long as the resonant frequency is below being audible.

 

[ndm]

I was thinking because of the higher resonant frequency, but in thinking more, it would likely still be below being audible.. In fact, being stiffer might actually be better as long as the resonant frequency is below being audible.

Soooooo....are you on board with this concept... maybe some testing

 

[JoshHefnerX]

You have to have some kind of de-coupler below your 'mass'. Mlv works because it's floating above and de coupled from the metal which is moving and thus transmitting noise.

Similar to the suspension in your car. Your wheels move along the road, your cockpit stays relatively stable. Sound studios are built in a similar fashion w/ 2 separate walls to decouple them from one another.

Josh

 

[ndm]

You have to have some kind of de-coupler below your 'mass'. Mlv works because it's floating above and de coupled from the metal which is moving and thus transmitting noise.

Similar to the suspension in your car. Your wheels move along the road, your cockpit stays relatively stable. Sound studios are built in a similar fashion w/ 2 separate walls to decouple them from one another.

Josh

Yes,I stated that above. You would use the same process as installing mlv but use cld deadener instead. If the cld is the heavier stuff like 1lb/ft2 then you could adhere the closed cell foam to the sticky side of the cld. If the cld is the .6lb/ft2 then use 2 layers plus foam.

Im not saying that this method would be the most prefered method at all. I am simply entertaining the concept that it would work.

I mean you can build a pretty good home from lumber...it is the standard way homes are built. Building one out of metal can also be just fine too.