DynaMat and MLV (Mass Loaded Vinyl)

[mdsalemi]

I happened to note, in another thread, the use of DynaMat, as well as MLV.

As I now live in a warmer climate than in the past (NC instead of MI), the heat buildup in the passenger compartment of my Pagoda is extraordinary, to an uncomfortable level. Road noise and other external sounds are a secondary concern.

The purpose of this thread is for those owners who have used one or both of these products to share their experiences, results, pitfalls, dos and don'ts, etc.

I for one would like to hear about how the products were used and your results, I'm sure others would too.

References:

https://www.dynamat.com
https://soundproofguide.com/mass-loaded-vinyl-mlv/. some facts as it were...
https://massloadedvinyl.com   A supplier

[66andBlue]

Michael,
I have used Dynamat in my 1966 230SL and MLV in the 280SL. They are used mostly for sound deadening, although Dynamat claims that it serves both purposes.
Have you seen this discussion here:
https://www.sl113.org/forums/index.php?topic=27533
Unfortunately, Dan, at sounddeadenershowdown, one of the most knowledgeable people in the car sound proofing business closed shop.

If your car gets hotter on the passenger side then check the heat shields at the exhaust pipes and make sure they are clean and reflective. More on heat shielding later.

[mdsalemi]

Michael,
I have used Dynamat in my 1966 230SL and MLV in the 280SL.

If your car gets hotter on the passenger side then check the heat shields at the exhaust pipes and make sure they are clean and reflective. More on heat shielding later.

Thank you. Why did you use DM on the 230, and MLV on the 280? What's your assessment of the outcome?

I will check heat shields...

[66andBlue]

Why?
1. When I got the car in 2007 first thing my wife complained about was the noise.
2. I noticed that the automatic shifter console on the tunnel got extremely hot.
3. I fell victim to the marketing hype of Dynamat believing that it would improve both.
4. I covered every bit of the interior. But I cringed every time I saw the shiny bright foil and trademark. I should not post the photo since I am still embarrassed. 
5. When time came to work on the 280SL I spent considerable time with the fellows at Super Soundproofing Company in San Marcos to find out what MLV is and what it can improve and what not.

Outcome?
The 230SL interior was still hot in Missouri, less so here, no surprise of course. The automatic transmission just radiates a lot of heat after driving more than 50 miles in hot weather.
The 280SL is markedly quieter with the MLV. But it does add weight!

[GM]

Anyone have any experience with this for thermal insulation?
https://www.secondskinaudio.com/heat-insulation/heat-wave-pro

[dirkbalter]

I found that all the insolation manufacturers claim to have the best product one way or another. I did a search and comparison and ended up with an Eastwood product called X-Mat. I like that the aluminum barrier is sandwiched in-between the "rubber" layers  and not visible. A bit pricy but great to work with. I will probably add a layer of felt prior to carpet.

[Shvegel]

I used Dynamat only on the floor pans to match the original tar boards.  On my car the tar boards were painted body color after installation so I ended up rolling paint over the Dynamat.

[johnk]

I did the Xmat as Well but then I sprayed black sound deadener over that to look like original floor in case anyone peaked under my carpet.

[mdsalemi]

Heat insulation does work. How well is a relative thing. It's no cool ride in a Pagoda in the heat of summer at mid day. The heat insulation materials reflect some of the heat back and prevent some heat from being transmitted, but they don't keep the ride cool. The silver foil part does make a huge difference. It's called a "radiant barrier" and they have been using if on home's roof decking now and it's pretty amazing. I also went to visit a local "backyard shed" manufacturer recently and they used that on the roofs, and there was a significant difference between walking into a shed with the radiant barrier roof sheathing, and one with conventional OSB.

I will probably try something like that second skin product. It looks much like some material give to me by an automotive supplier once to do just that--but I only had a sample of it not enough to do much.

All of what you did with the DynaMat, Alfred, was soon to be covered in carpet so not certain I understand your concern. If it improved your ride so your wife will go with you, great.

[lreppond]

I’m about to re-carpet so this thread is very salient to me right now.   My only experience has been with Dynamat in one of my doors that required some internal work.  While it was opened up I gave the mechanic the go ahead with applying Dynamat.  Just that little bit made a noticeable difference in sound.  And an added bonus was the door sounds very solid when closed especially when compared to the other door without the insulation. 

I had never heard of MLV until Michael mentioned it.  I looked it up and it appears to be a great product but looks very thick to me and I wonder how it will look once covered with carpet?  And will it affect the fit? 

[66andBlue]

Heat insulation does work. How well is a relative thing. It's no cool ride in a Pagoda in the heat of summer at mid day. The heat insulation materials reflect some of the heat back and prevent some heat from being transmitted, but they don't keep the ride cool. The silver foil part does make a huge difference. It's called a "radiant barrier" and they have been using if on home's roof decking now and it's pretty amazing. I also went to visit a local "backyard shed" manufacturer recently and they used that on the roofs, and there was a significant difference between walking into a shed with the radiant barrier roof sheathing, and one with conventional OSB.
I will probably try something like that second skin product. It looks much like some material give to me by an automotive supplier once to do just that--but I only had a sample of it not enough to do much.
All of what you did with the DynaMat, Alfred, was soon to be covered in carpet so not certain I understand your concern. If it improved your ride so your wife will go with you, great.

Michael, I wish it did. The perceived improvement wasn't enough for her. 
I am hesitant to add more because improving noise and temperature comfort to everyones satisfaction is one of those unsolvable tasks, it involves the laws of physics and individual preferences. Ever tried to square a circle?  It is not possible to achieve both, maximal heat control and maximal sound control, with a single product.

1. Sound entering the cabin is structural sound and environmental sound, one requires sound dampening materials and the other sound absorbing materials. There are standards for each that would allow a more objective comparison between products but few independent labs equipped to do that. Few sellers of these products provide such data and if they do we still have a problem deciding which one is better. See: "Acoustic Loss Values" attachment.

One courageous individual, "Toostubborn2fail", started to test all relevant products that were donated to him, to make this comparison easier:
The results of his first series of tests are here: https://www.diymobileaudio.com/threads/sound-deadening-cld-testing.146403/page-87
This was followed by second series unfortunately it is not easy to find the results for the products he tested. He moved this apparently to Facebook:
https://www.diymobileaudio.com/threads/cld-testing.415165/page-15.
The company coming out on top [Resonix] has summarized his work to promote their product. You can find about this here:
https://www.sl113.org/forums/index.php?topic=33565
--

I’m about to re-carpet so this thread is very salient to me right now.   My only experience has been with Dynamat in one of my doors that required some internal work.  While it was opened up I gave the mechanic the go ahead with applying Dynamat.  Just that little bit made a noticeable difference in sound.  And an added bonus was the door sounds very solid when closed especially when compared to the other door without the insulation. 

Why was the original dampener removed"
The good news is that the Mercedes engineers were well aware of the problem and showed us already where to apply the "anti-squeak" in MB jargon if you want to add more or are inclined to scrape it off. 
--
I'll add another comment on the heat problem later when I have time again.
Meanwhile you may bone up on the physics and thinking about what diffusivity means. 

https://www.youtube.com/watch?v=Htmi5J8zbQM
https://ctherm.com/

https://www.youtube.com/watch?v=LR5bYxC4syI

[JamesL]

https://www.insulation-actis.com/multifoil-insulation/triso-super-10-plus.html

I have this under my carpet. Lightweight too