For the minimum testing (vibration, short term heat failure, long term heat) I'd need a 6"x8" piece.

Dustin, nope, no Fatmat yet. As of now, what I have left in my possession is GTMat 50mil, 110mil, and onyx, STP gold, silver, and vizomat, and Lightning Audio deadskin.

I have Memphis Mojo Mat on the way, and I believe some Audio Technix as well.


Ken, I'm going to call you in a few minutes, I've been meaning to do it, its just been crazy busy this week.

 

I have some BXT II I'd like to donate for testing. Please PM me an address so I can ship it.

One small request; can you test a sample (any sample) with double 95% coverage? I think it would be worthwhile to see what the actual returns on this are.

 

I can provide fatmat and rattletrap if needed.

Also if you're up to it, can you compare aluminum flashing adhered with rtv sealant? I can provide samples for that as well.

 

I'll see if Dustin (a local) can get the fatmat, if not, I'll let you know. Rattletrap and the homemade solution would be very interesting to test. I'll pm you after I get find out from Dustin about the fatmat.

 

Just so everyone knows, I talked to Ken from Second Skin today. He said he would be sending out a sample for these tests, in addition to their own independent test efforts.

I also received a rather large shipment of SDS CLD Tiles. Don had told me over the weekend that he would like to send me some samples for this testing. I am going to email him before I open them to make sure he's still ok with me testing it, if not, I am going to send it back. I don't feel right testing it with him being the donor, if he is not ok with the tests.

I was advised it would be good to remind everyone of the reasons behind this testing, as most people now are understandably skipping the first pages where it was contained.

My #1 purpose with this testing, is to get an idea of how each of these products perform, in a relatively controlled environment. I saw a lack of testing of any kind for these products, aside from a few ASTM-756 tests, which as Don and I agree, is not very indicative of how these products perform in our use. The testing I am doing, is sort of a preliminary testing. With the budget at hand, I have done everything I can to control the circumstances and give each product a fair chance. After I get through the samples I have, I will likely spend a month looking over everything, and putting together a very in depth report, including disclaimers that all testing of any form is limited in scope, and with every circumstance being different, that this is more of a guide to products that perform well. At that point I will take a break, as I've been working on this for several months when you include research, and I will likely be having surgery this fall. At some point early next year, I will begin preparing for a more in depth test, with the ability to test at multiple temps, with either an accelerometer, or non-contacting vibration sensor.

The secondary purpose is to test certain claims that have been made over the years. While I agree that there is diminishing returns from double layering, more than 50% coverage, etc, I want to know what those diminishing returns are. There are many more reasons to use these products than just quieting road noise, as Therapture showed with his waterfall plots from before and after roof deadening. I will be doing similar, with some in car tests at the time when I am able to work on deadening my wife's car. I at no point have, or will claim that these results are absolute for every circumstance, but that they do make it easier for people to make their own decisions about how to best treat the problems they have.

 

Thanks for doing this.. even if it is not 100% "scientifically perfect" testing, it still gives a non biased, and consistent way to compare the products. I am thinking even if the measurement isn't the most perfect way to do it, and the "numbers" aren't spot on as far as frequencies etc, you should still be able to pick out better performing items based on comparing your results. Thanks again!!

 

Thanks DJ.


I want to clarify something on the coverage testing. When I did that testing, there was a very obvious reduction in the resonant frequency. However, it is still way into diminishing returns land. While I did hear a difference, it was minimal compared to the difference between no coverage, and 25% coverage. Lets say a panel is 4 square feet and your deadener of choice is $5 per square foot, and lets say the product and results scaled up perfectly.

For $5, you would get a 13db reduction in resonant frequency, an across the board reduction in resonance all the way up to at least 1000hz, and a significantly changed waterfall pattern, showing a very good reduction in ringing.

For another $15, you would get a further 8db reduction in resonant frequency, another slight reduction in across the board overall resonance, but no real improvement in the waterfall plots, meaning the reduction in ringing doesn't really change.

In other words, 400% the cost gets less than 160% the results.


As some people were suggesting that CLD does block some sound, I will be doing some testing of that as well. I have some luxury liner pro from my last build, and some raw mlv from SDS, so I'll test both so we can see what the difference is between materials in blocking sound. That said, from personal experience, I am a firm believer in using a barrier to block sound, rather than CLD, unless the microphone proves otherwise.

I have a lot of products on the way now, so final results are going to take a little longer. I'm going to try to do a better job in the meantime of explaining what we are seeing when I post the graphs, and the realistic use of the results.

 

I gotta say. Huge undertaking. Hard to believe as long as this stuff has been in the audio world, no independent test like this has really been done. It also shows how interested people are in some data on the subject. This thread appears to have become quite the hot topic. Strong work.

 

Thank you for doing this TSB.

Is Thumper sending some Rattle Trap...if not I have some I can send in. I will not use their products anymore out here in the AZ heat but I certainly would like to see it tested.

 

I do plan to test both 50% and 100% again, but that will probably be it. At this point, anything over 25% is going to show up as a diminished return in terms of vibration damping. The fact that quadrupling the coverage only gave a 60% increase at the resonant frequency, and much less everywhere else, means that 50% coverage will also lead to diminished results. I would actually put money on the most damping per dollar at somewhere under 25%. Maybe 20% or so.


There are absolutely cases where more than 25% may be needed, but for the vast majority of people, I feel its wasted money. If your considering adding more than that, ask yourself why. Is there a specific issue that your having? Are you going after every possible gain (and have the money to spare to do it). And I'm going to say this now. If any company ever tells you to start with 100% coverage, they are either lying through their teeth to make more money off of you, or making up for an under performing product.


BTW, on my last build, you can see that I didn't follow these rules myself. That said, I'm one who usually doesn't mind going after diminished returns. Just look at the kick panels, I could have stopped at just concrete, but I added 9000 steel bbs. Did it help? Maybe 0.0001%. That said, any future deadening I do, will start at 25%, and I will take measurements if I'm going to add more.

 

Fascinating stuff guys!

 

Got the fatmat and damplifier pro. Working on tests right now.

Praetorian, there are plans for the double coverage test, I just want to get the comparisons done first. Its a pain to removal the full coverage pieces.

 

Did I miss one? Was/is there a GTMat Onyx test yet?

 

I've been working on heat testing, since we've had to watch our nieces since thursday. It was really possible to get the house quite enough to test with them here. They're gone now, so I will vibration test Onyx, STP Gold, and Silver today. If there's time, I'll also start with the remainder of the asphalt products. I can't test any of the new products that have come in until I have the chance to cut them monday with the stamp.

 

Will we be able to know if laying the CLD vertically gives more benefit than being messy laying horizontally or from bottom to top as some have mentioned?

Or is it just a myth when doing the 25% coverage?
No need to do testing for this, it is just a question that I'm sure can be answered without doing a test. I asume just place it anywhere where we think it will have the most benefit using the knocking method, without worrying about looks for a picture display :laugh:

 

That's a very complicated and loaded question. The reason I marked the center of the metal for testing, is because different points of each panel will have different resonant properties. Generally speaking, the resonant mode at the center "should" be the strongest, but weird panel shapes can change this drastically. I chose the center, because it was the easiest to position everything, and that's usually where most people start. I would expect rectangular pieces to have the same effect whether laid vertically or horizontally, as long as the center of the rectangle is in the center of a square, flat piece of sheet metal that's terminated evenly on each side. Anything else, and it would have to be measured to know.



One of the things I plan on doing next time I test, is testing a rectangular piece. I plan on testing different places on it. This is a long way off, but its something I think we could all learn from. I also want to test different thicknesses, and at all different temps.

I do plan to test a single square 25% coverage piece, vs 3 smaller pieces that add up to 25%, as I know that has been mentioned. But, it will be far from a definitive test, as there are thousands of combinations that could add up to 25%.


In the end, I don't think I'll do very specific ranks, instead focusing on tiers. Some of the products perform so close, that small variations could change the outcome. Then, some products or groups of products have set themselves apart from others very clearly. And obviously the heat testing will play a role. What good is a great performing product, if it can't stand up to actual use in a car.

 

Thanks, I was just wondering since I heard some members say to lay it vertically but my guess was it was just for looks.

What about the side placement effects, or what side of the metal benefits the most? In other words, if we could deaden the inside of the inner door wall, would that give better results than the side facing door panel? Not sure if the method used for testing can gives us an audible difference or anyone else can tell just based on experience. Thanks!

 

The current test box wouldn't be able to test is, since a flat panel would likely test almost identical no matter which side you put it on. Complex panel shapes might test differently, but are also inherently much more difficult to test. I do absolutely believe that treating both sides of the metal, like in the case of the door panel, would turn up better results than doubling layers would. That's actually a good idea to test, I'll get that worked in after the product comparison is done.


I apologize for the lack of updates, I had to replace on of the hurricane nuts and bolts sat and sunday. I had planned to test last night, but the whole county lost power last night. Kind of sucks, it was perfect as far as background noise level, but couldn't test without power. I verified earlier that the new nut/bolt hasn't changed the results I'm getting by doing multiple metal tests, which all ranged in between the current high and low tests of the bare metal. I'll be testing at least two products later today when the house quiets down.

 

I was just wondering if you are still testing, I have some audio technix 60 mil I would be willing to donate if you are interested.

 

loving this thread

any chance to getting a sample of the new GTMat Quadro to test?

 

I believe I have some coming.

 

STP-Atlantic Gold

Actual Measurements

Total Thickness - 85mil

Constraining Layer Thickness - 4mil

0.85 lbs per square foot

Notes - Very clean removal, just like STP-Bomb in that respect. Overall well performing.

Bare Metal Frequency Response


Damped Metal Frequency Response


Overlay of Undamped Metal vs Damped Metal Frequency Response


Bare Metal Waterfall


Damped Metal Waterfall

 

A thought occurred;

Have you(or anyone) performed any temperature tests on this product? It seems to perform similar to ours at room temperature, but a product's effect will vary greatly between 60 and 100 degrees Fahrenheit. Many places exceed these temperatures for a good portion of the year in winter and summer.

 

GTMat Onyx

Actual Measurements

Total Thickness - 80mil

Constraining Layer Thickness - 4mil

0.57 lbs per square foot

Notes - Very very gummy butyl. Almost like the real sticky chewing gum. Odd choice of backing paper, but it works. This one is tricky. On first look at the frequency response graph, it doesn't look much better that GTMat Ultra (80mil). However, comparing the two waterfall plots, the vibration decays much better than GTMat Ultra.

Bare Metal Frequency Response


Damped Metal Frequency Response


Overlay of Undamped Metal vs Damped Metal Frequency Response


Bare Metal Waterfall


Damped Metal Waterfall

 

So, there's a couple of things about the last tests that I wanted to expand on, one thing that I have learned, and one thing that I want everyone to take away from this.

The first thing, something that I have learned, is you can't tell how something is going to perform by their published specs. A thick constraining layer is great, decent butyl thickness is nice, and all butyl is a good thing. But, even with all those things, the differences in the butyl formula can make or break a product.

Looking at the tests from last night, STP Gold, and GTMat Onyx, are close enough in published specs that they should have performed similar. But, in the situation that I am testing under, Gold tested significantly better in every respect. There was a hint that this might happen before actually testing when I was measuring each one, as Gold was 48% heavier than Onyx, even though Gold was only 6% thicker, and had the same thickness of aluminum. But, that's not conclusive either, as Dynamat, the lightest butyl product so far, performed better than Stinger Roadkill Expert, which is both heavier and thicker, and has a thicker aluminum layer.

So, what have we learned so far? There is no way to tell from constraining layer thickness or butyl thickness, or weight, how well a product performs compared to another. Meaning testing is needed, and this makes me more determined in the future to test again, with a better set up.

 

So the second thing that everyone needs to take away, is that the waterfall plots are far more important than the frequency response. Last nights tests are a perfect example as well, if we compare GTMat Onyx to GTMat Ultra (80mil).

Looking at the frequency response graph, we see that Onyx lowered amplitude by 2.89db at the resonant frequency. It also lowered the resonant frequency by 12.5hz. Ultra (80mil) lowered amplitude at the resonant frequency by 3.29db, and lowered the resonant frequency by 5.7hz. Seems pretty close right?

Lets look at the amplitude over time. From the initial impulse to the 100ms mark, Onyx lowers the amplitude at the resonant frequency by 11.1db, while Ultra (80mil) only lowers it by 8.1db. Going further out in time, they separate themselves even further. From impulse to 200ms, Onyx lowers amplitude at the resonant frequency by 30.3db, which Ultra (80mil) only lowers it by 22db. Going to 300ms would separate the two even further.

While the initial impulse changes between the two aren't significant, the changes in amplitude over time, are. The difference is audible. Ultra (80mil) still rings, while Onyx decays much faster.

 

Me like what I'm seeing.

Keep this up

 

Deciding between the Audio Technix 80mil and the Knu Kolossus and Damp Pro. Thanks for this. Just in time for what I was needing to know.

 

Damp Pro should be tested tomorrow, along with Raamat, STP Silver, and Memphis Mojo Mat.

That said, keep in mind, I still have heat testing to do, and that will play heavily on how I rank these products in the end. The best damper is no good in my eyes if it can't stay attached to the roof when its 110 out, or on the firewall.

 

You are simply an awesome person for doing this testing any making your findings public. Thank you! I look forward to reading the results!

The worst Instagram you've ever seen.... @ dawiz711