# Multiple layers of Dynamat... Better?



## 000zero (Mar 12, 2011)

I have only one layer of Dynamat in my door currently. If I add multiple layers will the sound improvement be that much better then a single layer?


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## 000zero (Mar 12, 2011)

I have only one layer of Dynamat in my door currently. If I add multiple layers will the sound improvement be that much better then a single layer?


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## trunks9_us (Oct 25, 2007)

Now to answer your question. It all depends on how mig the speakers are in the doors. 

1. it wont be a major difference but if u ran 8 or 10 inchers in the doors it will help out 6 n half 1 layer will be sufficient

make sure u try to make the doors as much sealed as possible it will help out for midbass punch. also. make sure u have a good seal from the speakers to the door that way there wont be energy loss. on top of that a deflex pad would be helpful to. thats a good start right there. if your going to competitions then look at my build log if u want real deadened doors


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## Brian_smith06 (Jan 31, 2008)

There is a potential chance it could sound better but very small. Does anything still resonate? If so then def add some. Or if you just happen to have extra material and want to use it put it directly behind the mid on the outer door skin.


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## Oliver (Jun 25, 2007)

000zero,

*What is da prob ?*

Figure out the problem then ATTEMPT to fix it.

1] sound blockers

2] mass loading = dynamat

3] decoupling , etc..,


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## 000zero (Mar 12, 2011)

There is no problem necessarily I just recently added the Dynamat to my doors and the sound improvement was night and day, so I was just wondering if adding more would be worth it. However, from these replies there are now two things that I would like to now: the first is add the dynamat to the part where i mount my speaker to ensure a good seal, second I will add the Deflex pad.

trunks9_us where can I find your build log?

Thanks to all for the info


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## Brian_smith06 (Jan 31, 2008)

Definitely mass load what your mids are mounted to if that's what you're now asking. And make sure rear waves can't come out and play with the front sound waves. Never ends well and somebody always ends up getting stabbed


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## raamaudio (May 4, 2005)

I always add a smaller second layer behind my mids, if really high output I might add a third layer and have the second one larger than normal. Instead of 8x8 or so it might be 10x10, 12x12, etc depending on the door shape, size. Then I put a piece of Ensolite over the last layer of mat, 8x8 or so, to break up the back wave, decouple it from the door, etc....

The only install I added more mat than that was my dual 300 watt per mid install in my old taco, my very first version of RAAMmat, 45 mils, 7 layers tapered out to just 2 at the furthest extremes of the door skin. 

I have used Ensolite effectively behind Rainbow References, never felt a need for the more expensive products like deflex pads(I tried them). 

If putting a high power setup in the doors I also use some aluminum channel, diagonal, vertical, one to three or so sections, to brace the speaker mounting location. I do this by bending to shape and holding them behind the sheet metal, drill in with self taping screws, it makes a big improvement, did so on my Duramax doors, really helped the the x69 ID and 250 watts per door

I always seal up every hole in the door, all those access holes and the little misc ones, the Duramax was almost all hole, very little sheet metal, I had to really go after them but sure working great now

Rick


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## Eastman474 (Jan 8, 2010)

I've never found reason for over 2 layers of deadener, as long as its good product.

Usually i run one layer inside the door and one layer over the front panel that the speaker mounts on.


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## raamaudio (May 4, 2005)

My original RAAMmat was half as effective as the BXT version which is less than the BXT II..just dirt cheap so use a ton of it. 

If you have 600 watts RMS per door and want to play at live listening levels, and beyond, it can take some serious deadening. 

I have 250 per door now and incredible midbass, just one layer of BXT II on maybe 70% of the door skin, one more layer behind the speakers, one layer of Ensolite, it does all I need there. 

I still added one aluminum channel to the area next to the speakers to stiffen it up and then covered all the access holes with sheet metal, mat and foam. I might still need to do a bit more but mostly the door panels themselves which are around 40% covered with mat and foam. I also used silicone sealer on some areas, etc...and still have some resonance issues, at high volume level only, I only play it that loud when doing a demo, I want to keep my hearing

Rick


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## Aaron'z 2.5RS/WRX (Oct 24, 2007)

I've got 4 layers in the mid area, tapering out to 1 layer near the door handle.. 

Part Cascade, mostly SS.. 

I own a Subaru, about the flimsiest car there is... so I had my work cut out for me..:laugh:


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## 000zero (Mar 12, 2011)

My I initial motivation for multiple layers was to reduce road noise, but I guess it makes more sense to do the floor in the rest of my car before I start adding multiple layers.


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## Aaron'z 2.5RS/WRX (Oct 24, 2007)

000zero said:


> My I initial motivation for multiple layers was to reduce road noise, but I guess it makes more sense to do the floor in the rest of my car before I start adding multiple layers.


Yes indeed... you are on the right path now... 

have you ever looked into the other forms of sound deadening, like CCF and MLV (both searchable)


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## bbotelhoHI (Mar 7, 2011)

000zero said:


> My I initial motivation for multiple layers was to reduce road noise, but I guess it makes more sense to do the floor in the rest of my car before I start adding multiple layers.


mass loading will reduce resonance, not airborne noise. for that, you want a closed cell foam, like second skin's overkill. alternatives would be stuff like velodyne, neoprene, ensolite, or exercise mat material.


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## Aaron'z 2.5RS/WRX (Oct 24, 2007)

It's to bad CCF doesn't do much for sound, but acts as more of a decoupler..

I noticed a difference when I CCF'ed the car, but not a huge one... biggest difference was the MLV..


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