# GT MAT Sound Deadner Product Review



## DeanE10 (Apr 19, 2011)

I know we all have our favorites but I just happened to get invited to a LOCAL (20 minutes from me) company today and got to see first hand quite a few products. The company is: GTMAT - Automotive Sound Deadner

I talked with Rich from Sales, Tracie from Marketing and even the owner Rhett was there. They have been catering to the Tuner/Restoration market for a little while now helping to get rid of the engine sounds and vibrations along with muffler drone. I asked them about the car audio market but they haven't moved too far into that direction yet.

I got a few samples of some products to include some super secret unreleased version of their Brush/Roll on Liqui-Damp and will be doing a full build log on my front doors since they still have some vibrations using the eDead product.

My favorite part was the warehouse... Theirs? The owner Rhett and Rich sat in my truck and got to hear how awesome a Hybrid Audio front stage sounds like  Needless to say, I bet they would have been Shocked as hell if I told I told them I didn't have any tweeters!

If you want to try it out for yourself, you can send them an email or give them a call and get a free 10 SQ FT Sample, here is the pictures of what I received:





































The below is my quick review of the product to show the typical application and a bit of proof of concept:

Empty Can Test:





Single strip test, one strip test 50 Mil:






Dual strip test, 50 Mil:






Liqui-Damp "X" - This is the new stuff not yet released. It is super thick!!!! I only applied one coat, and did a half ass job at it... Check the results:











Finally... My door tests... These are the before I used the GTMAT products so you can hear a difference:






This is the "After" I put a single layer of 80 Mil on the outside panel of the door, and brushed the inside facing panels of the door with the new Liqui-Damp stuff:






Adding some Scissor Handles to the mix cause I know they are noisy 







Ok, so that is my review, hope you find it useful.. If you want to try the product for yourself you can hit up the site below, here is the card again with the details:


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## [email protected] (Oct 25, 2012)

Thank you for the review Dean! If anyone has any questions, please feel free to ask here. I am new to the entire mobile audio world but will do my best to address your concerns.

-Tracie
GTMat


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## DeanE10 (Apr 19, 2011)

Welcome to the forums Tracie!

Don't forget to give the folks a call for your free sample. I did get quite a few txt's and IM's on the free sample...

@Tracie - Can you provide the details on how these guys can take advantage of the free sample shown in the card?

Thanks!


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## [email protected] (Oct 25, 2012)

No advertising unless you are an upgraded vendor

ANT was here


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## jriggs (Jun 14, 2011)

I sent an email Sunday and got a response in less than an hour. My free sample arrived today. Thanks!


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## PaulD (Nov 16, 2006)

I can tell you from experience with 3 different mats, if it comes out of the box that crumpled up it will be very difficult to get it flat. Most of the mat deadener companies sell their product in a flat box with mayb a fold or two (for the larger sheets).

just my .02


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## DeanE10 (Apr 19, 2011)

PaulD said:


> I can tell you from experience with 3 different mats, if it comes out of the box that crumpled up it will be very difficult to get it flat. Most of the mat deadener companies sell their product in a flat box with mayb a fold or two (for the larger sheets).
> 
> just my .02


Thanks PaulD! I had no problems with it at all, it was very flexible. Did you get your free sample?


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## TOOSTUBBORN2FAIL (Jan 31, 2011)

^that and the aluminum thickness is whats making me shy away. The ideal damping material would have the constraining layer as thick as the material your trying to dampen. Of course, this isnt practical, but 4mil thick aluminum is on the thin side. The website also says you can do multiple layers to deaden further, but fails to state that each consecutive layer is less effective than the one before it.


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## LovesMusic (Mar 29, 2012)

I really hate doing this but feel obliged to steer fellow diyma members in the same respect and manner they have guided me, in the "right" direction.
It would be a great dis-service to this community if I did not share my thoughts and experiences with GTmat.

About 5-6 months ago I was in need of more sound deadener but my pockets were empty. I searched ebay in hopes. Needless to say I ordered 10-15 sq ft of GTmat or whatever amount for $40, to get some deadener on my 2009 accord coupes floors.

I began unraveling the GTmat and applying it to the floor of the passenger side. My first thoughts I like the butyl adhesive easy to work with seemed to stick well. However I felt the pieces I was cutting were extremely light where is the mass? At this point in time I was taking a strength of materials class in my mech eng curriculum, consisting of destroying matter and studying its effects, where and why it failed.
I took the GTmat and began to litterally pull it apart in a vice to examine its shear. This unearthed the Fact that this GTmat it made with no aluminum whatsoever. The small mil specified by manufacturer can be very decieving as it looks and bends like a cheap aluminum however after examination with my eyes and microscope I was able to clearly see the mat is made out of some sort of poly plastic material/coating and painted in a way that it will resemble Aluminum. The paint would not flake or deteriorate job well done. As well as polys usually have a higher percentage of elongation, that they were able tame which was apparent in my stress testing, again the paint did a pretty amazing job holding with the minimal stretch when the shear was applied.

I emailed them with my findings. I was given a full refund and told to keep the rest of the product as they didnt even want it back. I thanked them for their quick response and action and told them I would not report my findings on ebays feedback, they did not ask this, I just am simply not that person. 

Money is pretty tight nowadays and Again I truly apologize for presenting this.


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## DeanE10 (Apr 19, 2011)

TOOSTUBBORN2FAIL said:


> The website also says you can do multiple layers to deaden further, but fails to state that each consecutive layer is less effective than the one before it.


Thanks for the feedback man but I am not sure I understand this part, can you explain it for me?


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## DeanE10 (Apr 19, 2011)

LovesMusic said:


> I took the GTmat and began to litterally pull it apart in a vice to examine its shear. This unearthed the Fact that this GTmat with no aluminum whatsoever. The small mil size can be very decieving as it looks and bends like a cheap aluminum however after examination with my eyes and microscope I was able to clearly see the mat is made out of some sort of poly plastic material/coating and painted in a way that it will resemble Aluminum.


Whoa...!!! You're saying the top is not aluminum? Could be my own ignorance but I thought it was!


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## LovesMusic (Mar 29, 2012)

DeanE10 said:


> Whoa...!!! You're saying the top is not aluminum? Could be my own ignorance but I thought it was!


Yes, The top is NOT aluminum 

Had I not been in the mechanical Eng and materials field I too would have never known any better. They apparently did some research in attaining a high profit margin.

sorry deanE


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## DeanE10 (Apr 19, 2011)

LovesMusic said:


> Yes, The top is NOT aluminum
> 
> Had I not been in the mechanical Eng and materials field I too would have never known any better. They apparently did some research in attaining a high profit margin.
> 
> sorry deanE


Is it even metal at all?


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## LovesMusic (Mar 29, 2012)

DeanE10 said:


> Is it even metal at all?


No.

It is completely made of plastic/rubber polymers.


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## TOOSTUBBORN2FAIL (Jan 31, 2011)

DeanE10 said:


> Thanks for the feedback man but I am not sure I understand this part, can you explain it for me?


Basically, the first layer you put on is actively damping the metal it is applied to. The aluminum's job is to try to maintain shape, while the butyl flexes with the sheet metal. The deformation of the deadening is what deadens the vibration. The next layer you put on is only actively damping the first layer of deadening, and so forth for every additional layer. So the second layer of deadening is trying to prevent the first layer of deadening from deforming.


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## jriggs (Jun 14, 2011)

So I opened my box of free sample tonight. Wow this stuff is THIN and light. Just do not sees this matching up well performance wise with known high quality sound deadening product. Sorry.


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## subwoofery (Nov 9, 2008)

Guess I'll stay with RAAMmat for now... 

Kelvin


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## DeanE10 (Apr 19, 2011)

LovesMusic said:


> No.
> 
> It is completely made of plastic/rubber polymers.


Well, this is wrong, I tested it tonight.. if it is not aluminum then it shouldn't be conductive... I will post my tests tomorrow. it is definitely aluminum or some other metal for sure.


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## DeanE10 (Apr 19, 2011)

TOOSTUBBORN2FAIL said:


> Basically, the first layer you put on is actively damping the metal it is applied to. The aluminum's job is to try to maintain shape, while the butyl flexes with the sheet metal. The deformation of the deadening is what deadens the vibration. The next layer you put on is only actively damping the first layer of deadening, and so forth for every additional layer. So the second layer of deadening is trying to prevent the first layer of deadening from deforming.


I get it.. so your saying that the first layer should be enough and by adding in a second layer you're only dampening the aluminum of the first layer so it's really not beneficial?



jriggs said:


> So I opened my box of free sample tonight. Wow this stuff is THIN and light. Just do not sees this matching up well performance wise with known high quality sound deadening product. Sorry.


Do a test like I did, people said the same thing about the Flashing (Peel & Seal) you can buy at Lowes but it actually works...


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## TOOSTUBBORN2FAIL (Jan 31, 2011)

Pretty much, and the thicker the aluminum, the better it will work. Sometime in the spring i plan to get a test set up using an accelerometer, and the leading deadeners, as well as peal n seal. Maybe ill order a sample of this stuff too.


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## schmiddr2 (Aug 10, 2009)

TOOSTUBBORN2FAIL said:


> Pretty much, and the thicker the aluminum, the better it will work. Sometime in the spring i plan to get a test set up using an accelerometer, and the leading deadeners, as well as peal n seal. Maybe ill order a sample of this stuff too.


That would be cool. Hope it works out.


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## LovesMusic (Mar 29, 2012)

DeanE10 said:


> Well, this is wrong, I tested it tonight.. if it is not aluminum then it shouldn't be conductive... I will post my tests tomorrow. it is definitely aluminum or some other metal for sure.




















Take note of the ripples, Aluminum does not exhibit these shear characteristics. This would obviously become much more apparent under a microscope. could be a cheapy dont matter.











Heated rubber up some, took a sheet of aluminum foil and began pressing it in, waited till the rubber hardened back up some and put it in a vice and sheared it just as i did the GTmat. 

Should be very similiar mil thickness. Sure we can get into why this is such an inaccurate test haha i wouldnt even call it a test, however it should explain Shear characteristics of aluminum a bit better and how they identify a particle specimen. Not only are its shear characteristics off but so is the GTmat's aluminum percent elongation.
Rubber is a nonlinear material which comes under hyper elastic materials. Deformation will be very much greater compared to linear materials(Aluminum).

Take any proven sound deadener, and attempt to attain similar shear characteristics as the GTmat. Chances are they are going to be similar to the aluminum foil. But what do I know... its conductive



I am no artist but Id bet that lots of artists use aluminum flake or other alloys and metals mixed in their paints to give them that "metal" look. 

Just want our boys here making informed descions.. Ill leave it at that, buyer beware


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## DeanE10 (Apr 19, 2011)

LovesMusic said:


> Take any proven sound deadener, and attempt to attain similar shear characteristics as the GTmat. Chances are they are going to be similar to the aluminum foil. But what do I know... its conductive


You have to understand my point and reasoning here... I put my name on this saying it's a great product and cheaper alternative... Because of that I have to defend it. I am more than willing to admit if I am wrong, but I just don't think I am, just like you don't think you are...

Not trying to insult your intelligence here but you said it wasn't metal at all and that wasn't correct on my samples. It is some type of metal as it is conductive but non magnetic. Maybe it is aluminum now and wasn't back then?

The cool thing about GTMat is they are just down the road so I am going to go there today to discuss this with them. Also, I plan to discuss changing the thickness if in fact the top layer is aluminum.

There is also a Metal Mart company just 2 blocks from there as well, so I am going to take a sample with me and have them tell me what the layer on top is.


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## benny (Apr 7, 2008)

I'll just leave this here...Metallised film - Wikipedia, the free encyclopedia


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## IBcivic (Jan 6, 2009)

Just put a heat gun to the suspected plastic film. If it melts... MYTH CONFIRMED


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## TOOSTUBBORN2FAIL (Jan 31, 2011)

Guys, this stuff is asphalt based. The website confirms it. It claims it is better than other asphalt brands like peel n seal, but its still asphalt.



> As noted in the comparison chart above, GTMAT is an asphalt based product like other discount brands, however compared to Fatmat or Peel & Seal, its adhesive layer is engineered with low-odor asphalt and higher heat resistance properties.


Also, *this* makes me think its just another re-purposed roofing product.



> - GTMAT Sound Deadener is an extremely durable product. *Rated at 20 years fail-free for exterior use*, this product will deliver a lifetime of service in your automobile. GTMAT is water, oil, solvent, salt, rust, and heat resistant.


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## DeanE10 (Apr 19, 2011)

TOOSTUBBORN2FAIL said:


> Guys, this stuff is asphalt based. The website confirms it.


Yep, it does have asphalt in it and they are not trying to hide it... Fact is, it still does the job it is supposed to do. You can dissect it all you want, until you can say that it doesn't work, what is your point...? 

I posted this review so that people can get the free sample and try the product for free. I am glad that you are posting details from their website though, just shows that they have nothing to hide 



IBcivic said:


> Just put a heat gun to the suspected plastic film. If it melts... MYTH CONFIRMED


Going to try this tonight, great idea!


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## LovesMusic (Mar 29, 2012)

benny said:


> I'll just leave this here...Metallised film - Wikipedia, the free encyclopedia


Thank you Benny, that sounds like a better theory then the paint and it's a polymer.. Like I explained before.. I mean I ain't blowin smoke here deanE.

I'd appreciate it if before you go all conan defending GTMAT and calling me out as wrong you take my thoughts and experiences as I don't receive anything for sharing this with our community, the truth of the matter. I understand your position but do not confuse me and my knowledge as some "kid" on the Internet. I'm not wrong and if I was I should probably get out of the engineering field... Like I said they made the stuff look really good... And that was to attain high profit margin. Put it under a microscope it's really thAt easy.




They have nothing to hide?!?! Holy balls how about the lie that their product uses 4 mil aluminum?!?! Wow if I didn't know any better I say they highered you as a publicist/sales rep 

I'm done forget contributing to this site back to the build logs...


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## DeanE10 (Apr 19, 2011)

LovesMusic said:


> I'd appreciate it if before you go all conan defending GTMAT and calling me out as wrong you take my thoughts and experiences as I don't receive anything for sharing this with our community, the truth of the matter. I understand your position but do not confuse me and my knowledge as some "kid" on the Internet. I'm not wrong and if I was I should probably get out of the engineering field... Like I said they made the stuff look really good... And that was to attain high profit margin. Put it under a microscope it's really thAt easy.
> 
> They have nothing to hide?!?! Holy balls how about the lie that their product uses 4 mil aluminum?!?! Wow if I didn't know any better I say they highered you as a publicist/sales rep


Nope, I am not on their payroll, not sponsored by, nor otherwise compensated by GTMat Etc...

Since the eDead folks went out of business I needed another cost effective alternative. I found GTMat, I liked how easy it was to work with them. and especially like how they are less than 20 minutes from my house. I got some samples and liked how easy the product was to work with as well.

Like I said before, I am not trying to insult your intelligence at all man, just letting you know that there has to be some kind of metal there as I tested corner-to-corner and it was all conductive.

I also said it could have been that you got a different batch than I have so it could be that the batch you got was that poly stuff and mine is actually aluminum... Maybe all of the emails you sent them worked and they fixed the product over the last few months?

Who cares... I put it on my doors, and all of my resonance went away, I achieved my goal, that is ultimately my point.

Also - Your build is looking great, I also have a Hybrid Audio (tweeterless) front stage and LOVE it... Another product I will stand behind 100%


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## PaulD (Nov 16, 2006)

DeanE10 said:


> Thanks PaulD! I had no problems with it at all, it was very flexible. Did you get your free sample?


I have no need for it, both cars I own are already done. Now that I know it's asphalt based, definitely a no thank you


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## DeanE10 (Apr 19, 2011)

Benny suggested a heat gun... I used a lighter instead...


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## TOOSTUBBORN2FAIL (Jan 31, 2011)

There are multiple contradicting quotes on their page. In one section, they state its a rubber product, elsewhere they state its asphalt, and then they state that it "has asphalt in it". It is still more than likely a roofing product. 

The problem is this, if its a rubber based product, then it may damp via viscoelastic properties. If its an asphalt product, then it is nothing but a mass loader. So which is it? That's a very important question, easily the most important question when buying deadener. If its a mass loader, then you need multiple layers to equal one layer of viscoelastic deadening. 

This would make sense why the website says you can layer multiple layers.

Either way, when I get my test set up, I'll send for a sample, and test it vs the top brands. It will be a purely objective test, showing what material damps vibration best.


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## DeanE10 (Apr 19, 2011)

Thanks for the clarity 2Stubb, that makes sense... When I talked to Rhett yesterday he said it was a rubber based product that has asphalt in it and that the outer layer was indeed aluminum. The site does need to be fixed, the more I look at it the more I agree with your statement of "multiple contradictions"

Rhett does explain the product here in much more detail...

https://www.youtube.com/watch?v=mwG5DCjNxbM


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## t3sn4f2 (Jan 3, 2007)

Why Not Asphalt?


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## t3sn4f2 (Jan 3, 2007)

DeanE10 said:


> Benny suggested a heat gun... I used a lighter instead...


"Little or no odor"

"Low odor"

That doesn't sound too good to me.


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## DeanE10 (Apr 19, 2011)

t3sn4f2 said:


> Why Not Asphalt?


Thanks for the link T3... 

I read this last year when others were talking about Peel & Seel and really good information about what to look for when the vehicle reaches 180 Degrees or more. 

I know this stuff was tested over the 300 Degree range before having any issues but will be interested to see how it pans out in the 3rd and 4th year like the link above talks about.


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## [email protected] (Oct 25, 2012)

Please stop advertising your product.


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## [email protected] (Oct 25, 2012)

Nope....


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## DeanE10 (Apr 19, 2011)

*Re: GT MAT Sound Deadner Product Review - New Onyx Product*

I just redone my floor and back doors with the new Onyx 60 Mil product. Solid stuff!


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## SeniorXJ (Feb 10, 2012)

Im about to deaden my front doors & am doing my research on all of these deadeners. My initial thought was to grab a roll of peel & seal as i was a roofer for 15yrs & i know its durability well. Im not willing to spend top dollar on these deadening materials so i went to ebay to see what they had to offer on a budget & found GTMAT at a very reasonable cost & it came in 50 & 80mil & there ebay page had alot of good info on it. 

I then took to youtube for further research cause videos often have very good info of a product in action & i typed in "GTMAT deadener" & found this 1st vid on a heat test:
GTMAT Automotive Sound Deadener Oven (Heat) Test - YouTube

Then this one on an audible resonance test: 
GTMAT Reduces Audible Resonance - The Bell and Cymbal Tests. - YouTube

Then the companies video thats been shown earlier in this thread:
What is GTMAT Automotive Sound Deadener? - YouTube

So heres my plan of action that id like to get some feedback from u guys on; i plan to buy a 10sq ft roll of the 80mil GTMAT for the outter & inner door skin giving it just one layer, then add a second layer of peel & seal. The heat shouldnt get to it as much with both inner & outter door skins treated FIRST with the GTMAT, the odor of the peel & seal should be minimal with just one layer of it, & i should get the propper amount of mass & sound deadening to my doors!

Sound like a logical plan yes or no?
Thanks!


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## DeanE10 (Apr 19, 2011)

SeniorXJ said:


> Im about to deaden my front doors & am doing my research on all of these deadeners. My initial thought was to grab a roll of peel & seal as i was a roofer for 15yrs & i know its durability well. Im not willing to spend top dollar on these deadening materials so i went to ebay to see what they had to offer on a budget & found GTMAT at a very reasonable cost & it came in 50 & 80mil & there ebay page had alot of good info on it.
> 
> I then took to youtube for further research cause videos often have very good info of a product in action & i typed in "GTMAT deadener" & found this 1st vid on a heat test:
> GTMAT Automotive Sound Deadener Oven (Heat) Test - YouTube
> ...


I would look at the new Butyl product instead, it is called Onyx. Not that the other is bad stuff, it is that most have preferred the butyl product over the asphalt based product.


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## cyrusthevirus23 (Feb 16, 2013)

LovesMusic said:


> No.
> 
> It is completely made of plastic/rubber polymers.


interesting i may have to try some of this on my evo


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## DeanE10 (Apr 19, 2011)

I did the latest above using the latest product from GTMat...

GT Sound Control Auto Car Sound Audio Deadening Deadener

I am still in the middle of a full product review etc... but so far the results are fantastic!

Good luck!


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## therapture (Jan 31, 2013)

DeanE10 said:


> Thanks for the link T3...
> 
> I read this last year when others were talking about Peel & Seel and really good information about what to look for when the vehicle reaches 180 Degrees or more.
> 
> I know this stuff was tested over the 300 Degree range before having any issues but will be interested to see how it pans out in the 3rd and 4th year like the link above talks about.


Sorry to revive this thread, I just want to add a few cents.

I used this GTMat product extensively in my front doors, door trims, rear deck, trunk, and floor. It worked very well and made a huge difference. I applied it correctly, forcing it into the crevices and bends, my arms were sore from working on it over several install sessions. I did use two layers, no big deal, the price makes that easy to do. I have twenty more sq. feet of it and that is going into my roof soon. I also used the liquidamp in the trunk/spare well, and it is great stuff. No problems at all with adhesion or application.

For the record, I had some small amounts of "peel and seal" applied a couple years ago...when I opened everything back up to do the job correctly...there was no falling off or loss of adhesion, nor was the cheap stuff (from Lowes) melted. It was stuck so well that I did not bother to remove it. I live in south Texas, and it's hella' hot here in summer, so if it was going to melt, it would have, in our 105f summers. My car sits in the sun at work all day and if the GTMat is better in heat than the cheap stuff...I am good to go.

Just because it's cheaper, doesn't mean it's junk. 

It is definitely a decent product, and the bang for buck is great. I think most of the failures with a product such as this are install related, i.e., not cleaning the mounting surface, not getting it pressed on securely, etc.

Yes, I am a noob to the SQ field, but I am no dummy, and sometimes the elitist knee jerk reaction that the most expensive product is the best, is not always true.

edit: my car did not get all stinky, it had a very light smell the first couple days and after that, it's gone, gone, gone. I keep my interior pristine, and had it been bad, I would have been pissed.


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## basher8621 (Feb 21, 2009)

I purchased a small amount of the 50 and 80 mil to test. My biggest issue is the foil or lack there of.


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## Sine Swept (Sep 3, 2010)

I've always took a liking to foil tape anyways, it's nearly become a commodity. The tape I use also seems to have a plastic binding layer in there as well. Being a Canadian I have been misled by this talk about "Mils". There are 1000 mils in an inch, by comparison there are only 25 millimetres "mm" in an inch. When people are talking the difference in Mils, I would say it is negligible between 50 - 80 mils.

I like the old piece of deadener on a piece of metal test. I chose flashing as its some noisy stuff. I take 2 4 inch circles of flashing, one with a tiny piece of whatever you have, then drop them from shoulder height to the floor. Even by using whatever I can find ( a marble taped to the metal ), the piece of flashing with the mass attached always wins the thud test. I learned that one from the first stereo shop I went into and have never seen anyone else with a user friendly demo of deadeners' capabilities.


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## SPLEclipse (Aug 17, 2012)

Sine Swept said:


> I like the old piece of deadener on a piece of metal test. I chose flashing as its some noisy stuff. I take 2 4 inch circles of flashing, one with a tiny piece of whatever you have, then drop them from shoulder height to the floor. Even by using whatever I can find ( a marble taped to the metal ), the piece of flashing with the mass attached always wins the thud test. I learned that one from the first stereo shop I went into and have never seen anyone else with a user friendly demo of deadeners' capabilities.


When Dynamat first hit the scene they gave all of their retailers a little bell with a glob of the product on it.. Dynamat off=ring. Dynamat on=no ring. I sold a lot of product that way.


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## Sine Swept (Sep 3, 2010)

I'm going to pass that on to a friend!


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## DeanE10 (Apr 19, 2011)

basher8621 said:


> I purchased a small amount of the 50 and 80 mil to test. My biggest issue is the foil or lack there of.


I like how folks keep saying there is no metal... I took a torch and a lighter to it and it didn't burn, discolor or otherwise show any indication that it wasn't metal.. I even posted the video showing me do it.. 


IT IS Aluminum !!


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## basher8621 (Feb 21, 2009)

Not saying it isnt. It is so thin, that is why I didn't care for it. One strip of say RAAM BXT II in my opinion gives much better results than one strip of this. I am in no way bashing the brand here, just stating my opinion.


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## DeanE10 (Apr 19, 2011)

Here is the thickness I tested with the new Butyl based product.. I tested one of the left over pieces I had from the above installation. In these pictures, you can see I stripped the butyl away to measure the aluminum. It is 4Mil thick as advertised.

To your point basher, I did not do this with the asphalt based stuff and probably should have. But the new butyl based product GT Sound Control is calling "Onyx" will be my only source for deadening moving forward. It costs less, and works perfectly.


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## TOOSTUBBORN2FAIL (Jan 31, 2011)

$100 for 20 square feet of Onyx. 4mil thick aluminum. 70mil total thickness.

$130 for 20 square feet of Alphadamp. 10mil thick aluminum. 60mil total thickness.

The alphadamp will absolutely work better, be lighter, and thinner, for slightly more. More than twice the thickness on the constraining layer, the important part. Remember, the ultimate deadener would have the constraining layer be the same material and thickness as the material that you are trying to deaden. Alphadamp is significantly closer.

You could also get Sound Deadener Showdown's CLD tiles. $108 for 20 square feet, with 8mil thick aluminum. Still twice as thick as Onyx, and only 10mil thicker than onyx overall.


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## DeanE10 (Apr 19, 2011)

TOOSTUBBORN2FAIL said:


> $100 for 20 square feet of Onyx. 4mil thick aluminum. 70mil total thickness.
> 
> $130 for 20 square feet of Alphadamp. 10mil thick aluminum. 60mil total thickness.
> 
> ...


In the grand scheme of things... you can't justify the cost for either over GT Mat for such a menial difference... Quite a bit of testing has been done with all of the top brands and the actual difference is very minimal...

If you don't like the product, don't use it... pretty simple. Seems odd that I post a review of a solid product that does exactly what it says it is going to do, at a cheaper price, and a few folks feel the need to shove a more expensive option in the way saying "it is better" when in fact it's quite close to being equal.


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## TOOSTUBBORN2FAIL (Jan 31, 2011)

What testing was done? If there was objective testing done, post it. The truth is, the constraining layer on both options I posted is twice as thick or more. So your paying 8% more for a 100% increase in constraining layer thickness, or 30% more for a 150% increase in constraining layer.

Again, if you have some objective testing data, post it. GT Mat's website has none, and their explanation of how there products work is seriously lacking, to the point of being incorrect. They fail to even mention what the constraining layer does, which is the only thing that keeps the product from just adding mass to the panel as a free layer damper.


It is well known that the constraining layer would ideally be the same thickness and material as the material being deadened. So can you really say that a 100% thicker (or more in the case of alphadamp) would perform almost the same.


I'll leave it at that for now. I have my accelerometer, o-scope, and amplifier for the accelerometer. I should be able to run some tests by may. I'll get some onyx, alphadamp, sds, and dynamat extreme, and maybe some peel n seal. I would put money on alphadamp performing TWICE as well or better than onyx and dynamat extreme (which do have the same constraining layer thickness). If it does, then Onyx isn't really a bargain, and the other two (alphadamp and sds) really are.


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## optimaprime (Aug 16, 2007)

What happened to the tests ?


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## astrochex (Aug 7, 2009)

optimaprime said:


> What happened to the tests ?


http://www.diymobileaudio.com/forum...ons/146403-sound-deadening-cld-testing-7.html


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## DeanE10 (Apr 19, 2011)

Chris (TOOSTUBBORN2FAIL) is performing a large test of all kinds of different materials & Manufacturers at the link astrochex just posted.


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## optimaprime (Aug 16, 2007)

Thank I am gonna give GMAT try.


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