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I was wondering how well Dynamat works for the rear trunk. I'm planning on either 1 Kicker S12L7 with a KX600.1 in a fiberglass enclosure, or 2 S12L7's with a KX1200.1 also fiberglassed enclosure. Will dynamatting my trunk prevent it from rattling? What else can i do to prevent rattle. I hate hearing cars rattle from stereos, i am going for SQ so rattle has to be at a minimum, if any.

 
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Dynamat is great, arguably the best product of the class, but it is expensive. I use RAAMmat and have been very pleased. Both are Butyl based and will stand up to heat and will not smell. Watch out for some of the other products that are asphalt based. Smell bad and fall off.

That said, none if these products are specifically intended to stop rattles. Rattles are the result of two hard objects vibrating against each other. These can be in the trunk latching mechanism, spoiler assembly, rear deck components or the like. When you increase the volume inside the car, you are basically making the car vibrate and loose things will rattle.

Sound deadening products can reduce vibrations - and therefore rattles, but you are more likely to have success by tightening or somehow isolating the rattling pieces.

The main purpose of sound deadening is to improve the accoustical properties of the car. First, instead of stopping the rattling of little pieces, by stopping the vibration of your sheet metal which will cause all sorts of noise and distortion of your speaker output. They also reduce panel flexing, which comes into play mostly for SPL. Finally, especially when used with some of the acoustical foam products, they keep road and engine noise out and your sound in. If your car is quieter your music will be cleaner and louder.

So yeah, Dynamat is great stuff. Sound deadening is absolutely worth the effort. Once you do it - and consider at least doing the doors in addition to the trunk, if not the whole car, you will not believe that anyone would bother installing a system without it.

 
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I agree. I compete in Usaci and Iasca sound quality and dynamat is all i use. I have had my doors, floor, and trunk triple layered. After this not only does it sound better, but rides alot smoother than my dads lexus. Dynamat will help prevent rattles at average and above average levels. However, if you crank it, it will probably rattle a little as 135+db is hard to handle

 
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Dynamat Xtreme is all I will ever use, until they make something better. Its just awesome. Just remember dynamat cleans up the sound and makes it louder, but does not stop rattles, just dampens vibrations

 
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I might have stated the case against sound deadening stopping rattles a little to strongly. The fact is, it will actually stop a lot of rattles, just by holding everything together, but that isn't the primary reason to use it. The real danger is in sealing off your access to a rattle and having to hack your way through what is basically heavy aluminum foil and 60 mils of glue to get to it.

A good approach is to make a temporary intall of your subs. Crank the system up and find and kill your rattles. Then put down the deadener. Then finish the installation.

The first time I did it I dragged out my home stereo sub, which barely fit in the trunk, ran 100 ft of cable into the house and used that to test things for rattles. There really isn't a substitute for sound to test for the vibrations you will be dealing with. I used to think my rearview mirror was perfectly stationary too. lol.

But definitely, if you are going to put any time and money into a system, deaden first. It will even make the stock system sound better than you ever imagined it could (not great, but better)

 
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One last note on this. Dynamat is probably the best product out there. There formulation is patented so they have a lock on that performance level, but there can be other things to consider, especially for the non-competing DIY user.

I use RAAMmat because:

1) It is way less expensive and so close to being as effective that for my less than state of the art setup, I could not tell the difference.

2) The aluminium constraining layer is softer, making it easier to install and much less likely to open an artery while you do it.

Everybody has their brand loyalties. Some is due to marketing, some to sponsorships and some is just the "Hey I spent 4 days gutting my car and laying this stuff down so it better be the best".

For a lot of people, a full install with Dynamat is going to be so expensive as to stop them from doing it at all. Don't let it. Pay the money, find an alternative but do it. Just don't use roofing underlayment if you live anywhere warm and care what things smell like.

And one last thing. Even with the sound off, like 2004_sq_champ said, your car will have an entirely different character. You just don't realize how much noise we live with when we drive. Everything is better in a quiet car.

 
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A few excerpts from teh Sound deadening FAQ. The second part is a budget install done by ocelaris, costing around $100 for the whole car. All of those products are tar based. They are all manufactured at two places. Personally, I prefer FatMat, as it's cheaper than the two. It's made the same, it's the same stuff. *** loading is going to stop resonance, not vibration, remember that. don't isolate the rattle and fix it before deadening, you're sealing the rattle in. I don't really feel like typing out a ton here, so I'll leave you with the cut and paste, and the url to the FAQ.

The stickys: http://www.7thgencivic.com/forums/sh...d.php?t=210136
The Sound deadening DIY/Sticky: http://www.7thgencivic.com/forums/sh...ad.php?t=84562

Search around a bit before posting, k? I'm not being a stickler, but this has been covered at least a billion times seems like.

I thikn its a very good idea to be promoting the fact the dynamat will probbaly not prevent rattles. But absorb vibrations? Im retty sure most of dynamat if not all is the type that merely raises panel resonance to prevent ULF (ultra low frequency) waves from causing resonance issues. regardless, a tip thread should be unimpeachable.

but lets not forget ALL the applications if we are going to say it cleans bass and makes bass louder! we use it to eliminate road noise, engine noise, raise bass efficiency, seal doors better than stock, etc, etc, etc! It might be better to leave the rest of the practical apps of dynamat entirely out of the tip thread, a tip thread is to give practical advice on how to act in a certain way as a reference.

thus "dynamat is not designed to prevent rattles" is probably a sufficient tip.

but heres the ultimate in offensive results of dynamat use. Ever install dynamat extreeme behind your door speakers? reflections off the aluminum plate often causes cone interferrence and make your sound FAR worse! But those who were willing to spend $40 or more on those small pieces of mat and then thought their performance increased would be offended if we insulted that use of money.

Mass loading is how you'll stop or at least make better rattle/resonance issues you may be having. This makes the panel/piece require much more energy to rattle or resonate. This, effectively, is what deadening does.


That said:
Dynamats a good product who's price isn't anywhere resembling merited.

Dymamat Extreme offer extremely similar damping abilities. FatMat is much easier to work with and has an awesome price.

If you have actual rattles, that's because you have 2 solid objects coming into contact with each other.. a deadening matt will not help rattles in any way, shape or form. What it works against is resonances, where a span of sheet metal or plastic is vibrating and producing it's own sound.

To properly deaden your car you have to tighten the trunk latch.. run a bead of silicone into the trunk frame webbing remove the rear deck and put 1/2" strip of gasketting foam along the back of the rear deck where it comes in contact with the rear window. This will kill the rattles. You trunk and sidepanels and rear deck at this point will still resonate.. this is where 2 Layers of Fatmat, Raammat or Brown Bread come in.. I'd never suggest Dynamat because of it's ludacris price tag and the mentioned above deaden jus as well and are easier to work with.

I've tested Dynamat Extreme, Brown Bread and Raammat in alot of tests and of all of them Dynamat extreme lost all but one.. scent. but it was virtually negligable with all 3.

Best adhesion goes to Brown bread which is the same as Fat Mat, easiest to work with goes to raammat60 for sure. Deadening wise 2 layers of any of these will make any panel pretty much acoustically inert.

Best Value, FatMat by far...second least smell, second easiest to work with, best price. deadening wise is moot. 2 layers=dead for all 3.



Stay tuned, I have a far less expensive method of deadening I'll be posting tomorrow. It'll cost you under 100 bucks and you should be able to do most of, if not all of it with this method. I don't have time to compose all of it tonight, but this should get you to thinking about it, and be forumulating any questions you might have




The following is from a friend that has already typed out my sentiments on the subject. I am not the original author, nor is this going to be grammatically perfect, words will be misspelled. I haven’t taken the time to go through it and edit that part yet, I’m trying to get the information up as quickly as possible to start the $$$ savings as quickly as possible. The pics in the link at the end are from his install in a Civic si. It’s all relative though. I’m in no way saying this is the only proper way to accomplish this, I’m just saying it’s a far cheaper alternative and is as effective, if not more effective than dynamat, fatmat, raamat, e-dead, brown bread, etc. I can’t justify spending all that money to be able to get the same effect from something cheaper. That said, let it begin:


I have added some pictures from my Sound dampening, note this is an Si, but the same will hold true for anyone... there's no "done" pictures, everything was half way when taking those pictures, I ended up using alot more asphault sheeting and jute by the time I was done. 3M spray adhesive is your friend with the Jute and doors/back panels

http://photobucket.com/albums/v511/O...und_Dampening/

best 100$ I ever spent, and that's ALL I spent. As good or better sound proofing than someone who spent 10x as much.

No offense to anyone who's spent a small fortune on soundproofing their cars...

the ONLY reason to use dynamat, fatmat, brownbread, or any of these kinds of materials is for weight. There are two kinds of sound dampening, mass loading and diffusion. You could poop on your door panels and have the same exact effect if your poop weighed as much as your expensive fatmat/dynamat/brownbread. All these products are asphault. Different ones have aluminum backing, plastic backing etc... the aluminum and small amount of alphault will stop very little if any noise from leaving your vehicle. What the asphault IS good for, is lowering the resonance freqeuncy of noisy door panels. Think of your door panels like a saw, hear how the saw twangs? sheet metal is like a huge steel drum (and Anything hard will conduct sound very well) Don't even think of using spray foam, it actually amplifies the sound compared to dead air space inbetween your doors.

Asphault sheeting comes from 1 factory in Indiana or Iowa (I forget which), and they're all the same thing, asphault. Lead sheeting is what they use in some of the better home speakers, sandwhiched inbetween MDF. Ever wonder why they use such heavy material as MDF? You really think that your Sub is gonna make 1/2" MDF explode? Not even... 3/4" MDF is used because it's really Fing heavy. Same reason they use that heavy ish in home speakers, because weight does not vibrate.

My reccomendation. 33'x3' =99 sq feet of Grace Company "Ice and Water Guard". Cost 65$ at a roofing supply store. It's the same thing as dynamat original, fatmat, brownbread etc... except plastic backed instead of aluminum, so it's easy to apply. I've been told people think it's thinner than dynamat, and it might be, for the price, you can add 10 layers for the price of 1 dynamat layer. Your choice.

Second type of sound proofing, dissipation of noise. The tool of choice here is fiberous (not rubber) carpet padding, also called 'jute'. The idea is the same as why you put pillow stuffing in your sub box, the minute strands diffuse the vibrations and turn them into heat energy. I put carpet padding everywhere, and that made the biggest difference of all in my car, under the carpet, back panels, door panel, trunk. Cost = 3.50$ sq/yd mine cost roughly 25$.

I guarantee if you could even find places for 100 sq feet of ice and water guard, and 40 square feet of carpet padding, your car would be leaps and bounds above anyone who spent 300-500$ on their sound proofing. I used 50 sq. feet of asphalt sheeting, and maybe 40 sq. feet of carpet padding and spent a total of maybe 100$ after everything was said and done.

Oh, and don't even bother putting asphault sheeting on your floor of your car, there's already more than enough built into the vehicle for most of those panels, just use it on ones that when you bang on will make a noise, If you can bang on your floor of your car and it makes a noise, you got alot more problems than sound proofing. They say take a Sub, play it at 40hz and walk around to your entire car and see what rattles, I would say most of the time it's plastic piceces, most people never get their systems loud enough to really shake their metal, and think by mass loading (adding mass to panels) they'll somehow make it quieter? mass loading doesn't stop sound, diffusion does, try the jute.

Brownbread and several others of the B-Quiet line of sound-deadening products are NOT asphalt and DO NOT smell like "Ice and Water Guard" asphalt on a hot day nor on installation. You neglected to mention this lovely fact in your otherwise excellent post. Most people don't like their $30,000 car smelling like asphalt

Some sound dampening materials are actually not mass dampening, if you want to get into the different types, that's another story. For example Dynamat extreme is vinyl stretchy material, and serves similar purpose of diffusion, turning vibrational energy into heat energy. These materials work just as good as if you put many layers of duct tape over your panels, they keep things from rattling, and tend to collect the noise. Point blank, these materials do not stop noise, merely turn what was many different panels into one large panel, it would be like welding the body panel onto the main chassis, only by the chassis's inherent weight do you lower the resonance frequency. Often times simply collecting all the resonances into one solid material is enough for the panel to be heavy enough to stop vibrations. But, the only way you are going to get rid of the noise is with mass, hence mass loading.

As to the smell, mine smelled for a day after, and haven't smelled it since. Hot days don't make a difference, never smelled. I think the "smell" issue is pretty much made up. As the asphault sticky side is what attaches to the doors etc... And if you don't think people with 30,000$ cars don't like the smell, then what about EVERY CAR already has asphault sheeting on it. Does your car smell like asphault when you buy it? No, because the smell goes away after a day or two. Take a car apart, see those maleable things stuck to your floor boards? They're everywhere, and every car maker uses them.

Adding weight helps maintain the directionality of the speakers instead of creating multiple focal points of sound (i.e. each vibrating panel is a sound producing point). Asphalt is a great choice, but is limited due to its smell, and also its limited adherence in vertical positions.

Unfortunately the only way to get rid of sound is mass. You can pick lead or asphault. I myself pick asphault because it's cheap. I personally don't know of any other mass loading materials.


quote: Adding a composite foam, i.e. Vcomp from B-Quiet helps eliminate road noise along with other noises by adding dead-space and aiding in the dissipation of noise. It is half the thickness of Jute and provides twice the effect. B-Quiet's L-comp adds a lead barrier which aids this effect even greater. Jute works, BUT it is really damn thick and raises your carpet to new boundaries thus causing your carpet to no longer sit properly, your panels to no longer sit flush, etc. If you have tons of room, then use this cheap alternative, otherwise, use a vehicle specific product.

By composite foam, what exactly do you mean? The couple of materials I have discovered in my search have been a sandwich of vinyl and open celled foam, which serves the same purpose as jute. There certainly are better materials than jute, home theatre installation companies have these compressed fiberglass panels that absolutely ate up sound, unfortunately compressed fiberglass is not maleable, and the regular fiberglass for insulation is too big (though it works just as well). And your right, jute is probably 3/8" thick, though if you have problems fitting panels back after adding 3/8" to your floors, that's not my problem, mine worked fine, panels fit back perfect.

Unfortunately there is a direct relationship between mass and thickness and sound diffusion. Either you get lots of mass (compressed fiberglass) which is unmaleable, or you get less compressed, like jute which is thicker. The more fibers in the path of the sound the better the diffusion. I don't doubt that composite foam/vinyl isn't a good material, I'm simply saying that for 1/10th of the price you can get 95% of the effectiveness of vehicle specific materials.

my rule of thumb is to rap the panel with my knuckle, if it makes a noise you don't like, stick your mass loading sheets there. the floor boards don't make a twangy sound like one of those old big hand saws (if you've ever heard the kinda sheet metalish wowooowwowwowoowow noise). If you think of that noise, and that's what you're trying to eliminate, you'll probably have a good understanding of what the purpose of those brownbread or dynamat sheets are for.

I put some sheets on the outer skin, and on the inner skin. Keep rapping it with your knuckle until it quiets down (assuming you're putting on more layers between raps ) The parts where the speakers go are also twangy sheet metal, I would put the sheets where your priorities are (probably doors first), and then back panels. Not sure as to the RSX's trunk, but I'm guessing there's some sheet metal there too, especially if you're bouncing your sub off of your trunk there might be some high twangy sheet metal there as well. Depends alot on what your setup is.

Doesn’t asphault sheeting give off an odor?
Nope. I think people who like to pay lots of $ made that rumor up to make themselves feel better about spending more $.

You also might hear it doesn't stick well. Well it does, everywhere. If it falls off, you probably didn't clean the surface well enough. I just used a sponge with warm water and soap, then allowed it to dry... ok, so I prolly wasn't that rigorous about cleaning, but some things I did clean... but it stuck everywhere, hasn't fallen down.

Of course any of the asphault based materials will smell while exposed to air, but once you put them on your car the smell goes away. It smelled the first day after installing it, but probably more just because the smell was in my garage than anything, after I took it out for a drive, never smelled it again.

Dynamat, Fatmat, BrownBread, ice and water gaurd, are all asphaultic based liners, some have different compositions, and the expensive brands swear that they use less volatile (read smelly) materials in their brand than ice and water guard... of course ice and water guard makers can't exactly stick up for themselves in this regards because they don't expect people to use it for that purpose, so the bigger companies can spew all the invective they want and get away with it....


What about road noise?
vinyl and "asphalt" based compounds aren't going to absorb almost any road noise, you would be better off with an insulation type fiberglass... like the kind they line air ducts with, and/or surround air ducts with, they whole point of those is to stop the high pitched noise. I used carpet "jute" the cheap fibrous stuff on the inside and it made a huge difference... just need to do my headliner and work on those seals some... But seriously, home theatre people install those fiberglass sheets in home theatres that if you put your ear within 1 foot of it, that ear is effectively deaf because there is no sound at all reflected off of that compressed fiberglass sheet... in other words, if I had a choice, Id' line my whole car with that stuff if it were cheap and flexible... second best would be the stuff they line air ducts with, same stuff, but not as dense.



Where can I buy this jute or the fiberglass stuff at, and what is it?
"Jute" is kinda grayish jumble of fibers that they use for carpet padding, home depot or any hardware store with carpeting carries it. Now be forewarned, there is also the rubbery kind too, that stuff doesn't help at all, so just make sure you get the grey fibrous nylon-ish type. It's really cheap.

As for fiberglass, The insulation part of a home depot/ Lowes carries lots of varieties, just imagine it being under your floor of your car, in your doors etc, and you'll obviously want something thin and compactable. Basically, high pitched frequencies are dissipated in the exact same way that heat is kept in... with the exclusion of hard foams, hard foams actually will make more noise! So fibrous insulation is the goal, jute has been recommended, but I recommend home depot insulation, anything that you can fit in between yourself and the road will help.

My test for good sound absorbers:

Get one ear close to the material, and then listen to sounds around you, good materials should make your ear close to the material sound deaf, since it's absorbing all the sound that normally would be reflected off hard surfaces into your ear. I rolled myself up in the jute in the home depot and rolled around in it to see how good it was... pretty good stuff

Anyways you get the idea, home depots have lots of noise hopefully so you can test your materials out. I love going down to Lowe’s, they have a trillion different insulations, I want to try this pillow type stuff in my headliner, and take my doors off again and put more fiberglass stuff in it. And it's LIGHT!

The carpet padding is called "Jute" there really isn't a brand name that I'm aware of, just ask any carpet person or home depot carpet department person and they'll know exactly what you're talking about.

As for the fiberglass option, anything similar to the Pink Panther (pink fiberglass that goes in walls) except smaller and as compacted as you can find works well. In Europe they use rock wool instead, just basically a different melted rock that's cotton candy-ish in texture/shape. Pink Panther is the only brand name I can think of.

Quote: Sound dampening mat helps slightly for road noise, but it's mostly for improving sound quality from speakers. Fatmat is a BAD idea inside the car. It will smell like tar for months, and maybe even forever. Dynamat has no smell at all and sticks much better. It's worth it. Make sure you install it well by using a roller. Heat gun would be even better, although not needed.

You can spend your money on the commercial stuff "fatmat", "brownbread" etc... but the only thing those materials are is asphault sheeting. There is no other way to get the "rattle" to go away except weight. Now if you just have stuff clanking around, just try a few layers of the Grace (the company) Ice and water guard, and seal all your doors and panels. The smell goes away in a week at worse, and it'll smell the first hot day, and then be gone. All the auto manufacturers use this stuff in the cars when they're built anyways, you're just adding more of it.


You can get asphault sheeting much cheaper at other locations. But they will not cut down on road noise to any signifigance. You need something to absorb the high pitched sounds like jute, the cheap carpet padding you can find at home depot, don't get the rubber stuff. I would use asphault sheeting to seal my doors and openings, and then use the jute on the inner panel. I have done this, it works well, cost less than 100$ for 100 sq feet of asphault sheeting (grace ice and water guard) and 100 sq. feet of "jute" the fabric type carpet padding.

I'm planning to put some type of sound deadening material in my car... that fiberglass stuff ur talking about, how much does it go for and does it smell like anything?? bad that is?? not like asphalt? btw, i just wanna kno wut ppl have in their car to keep road noise down? does it work?? thanx for the help guys

Well, for sound absorption, there are commercial varieties of vinyl/foam/asphault/lead sandwiches etc... that are probably the best sound absorption available. What home theatre companies use in their sound proofing materials is compressed fiberglass, I have 2 sheets of the stuff in my apartment, and it will suck up almost any noise. The problem with compressed fiberglass is that it's rigid. So probably the next best thing would be if you could compress ALOT of fiberglass into openings and/or wherever, but that is kinda ridiculous, so a nice alternative that isn't pokey, is the cheap carpet padding generically called "jute" because it looks like it's woven out of millions of different materials, kinda greyish. This stuff works pretty well, and is very pliable. There is already a layer of this stuff under all of your carpeting... I added a second layer everywhere, and it helped alot.

In home theaters, they seal and tie down anything that will vibrate, i.e. loose drywall by double drywalling... and then they'll line the entire thing with that compressed fiberglass see this place:
http://www.insulationworld.com

And then they coat it with a nice fabric on top... I'll give you the analogy in our cars... Seal everything. anywhere air can leak in, sound can leak in. So any panels that have outer skins and inner skins, seal with some vinyl or asphaultic sheeting (asphaltic is 10x cheaper), also any loose plastic pieces can be kinda tied or strapped down with the sheeting. Then I put a layer of jute on the inside of the doors, and all panels.

The Jute is light, the jute is cheap, jute works great.

The catch with jute is that you can't let it get wet, it will mold, so that's why I reccomend the sealing of the exterior panels. Oh and I'll put a plug in again for Grace "Vycor" or "Ice and water guard" it has plastic backing. much easier to apply than the foil based, and the plastic stretches, so when you apply it, it doesn't tear, and you don't have any aspahult exposed (the smelly part) except the very edges. Do a good job and make 2 or 3 layers and you will only have a little exposed edges, which of course you could duct tape over if you were real **** about the smell, but I never noticed it, my wife complained the first time it got hot, but she says it went away after that.

Hard things transmit noise, soft things absorb... Best to understand basically how it works rather than to just buy product X... because I've seen so many idiots put 3 layers of fat mat on their floors... IDIOTS... one claimed that there was no "OEM" asphalt sheeting... I graciously took his picture of his fat mat install, and circled the part he had not covered on the floor (read wasted 100$ on nothing) where there was a strip of opening... low and behold the asphalt sheeting was there. Not to sound pretentious, but there are a lot of people who can throw $$ at a problem and not think about it... I probably could be that kind of person, but I would never want to pay to not think, ok well we all do sometimes, but when you want the best no matter what, you have to think about it, and when it comes down to getting results, throwing $ at a problem just won't get you the best results.

In the very beginning, about the dynamat extreme losing everything... well, dynamat extreme is a vinyl sheet, not asphalt, so no smell, but no weight either. Imagine lots and lots of thick electrical tape, and that's what Vinyl sheets are... if it smells, it probably weighs alot if it doesn't, it's probably vinyl. And they all stink, to certain degrees some are less stinky, but it's so subjective, you can believe what you want. I call it all the same.

Just used to having to wail against the man who tries to talk trash about the informational part of sound deadening because they bought 300$ of brand X on a whim and now vehemently defend their decision which lacks merit in many respects. You can get the best for a lot of $ no doubt, but for 100$ and a lot of time and thinking it over, you can get 95% of the best... and most people who drop major loot over sound deadening are using it so recklessly that they will never come close to matching the results that somebody with 100$ and a lot of effort will produce.


More on Jute:
But Jute is not foam, i.e. the stuff with the bubbles in it that most people have under their home carpets... foam usually is less helpful in sound deadening, the fabric type stuff is what you are looking for, it's cheaper than the foam stuff. The idea is mass and lots of seperate particles to absorb and vibrate away the energy of the sound... so foam is one big piece and can't dissipate the sound energy as well as individual fibers.

Here is a good way you can think of sound absorption... Think of the ocean, and a beach, and if you've ever seen beaches that have eroded, and they put huge boulders or stones along the edge, those are the comparisons to look at. The waves of the ocean are the sound energy, and the boulders and the sand are our sound dampening materials. So with a beach, there are quadrillions of tiny particles, and each particle take's it's hit of the wave and kind of rubs it's neighbor, and makes a little friction. Add up all that friction, and that is how the sand diffuses all the energy that the waves make. With the boulders (bad for saving beach erosion) each boulder is so big that the wave being fluid, it jsut moves out of the way and deflects the energy elsewhere... it doesn't absorb anything, it just bypasses it.

So when someone recommends putting the hard foam in the doors, that would be the equivalent of using boulders on a beach to protect from erosion.. it just speeds up erosion and noise transmission. Hard foam does not individually vibrate so it transmits instead of losing energy to friction.

Compressed Fiberglass is the equivalent of beach sand... individual particles which by themselves are hard, but they are small enough to absorb the energy and vibrate their neighbors hence absorbing the noise.

The Jute is our best cheap alternative having lots of nylon/cotton strands which work similarly to compressed fiberglass... and when I say compressed fiberglass, I don't mean like the stuff you make custom sub boxes out of, I mean like the pink rolls you put in walls, except it's compressed to be very dense. see here:

http://www.insulationworld.com/default.asp

So we want a relatively hard material to react

soft materials aren't dense enoguh to really stop much noise...

The Jute is a hard nylon, but compressed/sewn or whatever... Something like neoprene (open celled) foam would work, but it's expensive and hard to come by.

In the home audio world we use fiberglass, a very hard material, it's just sintered glass, and the denser the better. So a light foam wouldn't hurt, but it would not be as good a material as jute or open celled real rubber like from trees rubber, not a plastic. But you have to be real careful, as some will actually transmit/amplify the sound... best to stick with jute or a dense fiberous material.

Now Hard foam like the spray expanding stuff will actually make it much worse, the closed cells, and the hardness of the foam when dry will very effectively transmit the sound right through the doors... so stay away from anything hard...

Basically, Soft good, hard bad...


q: So the "ice and water guard" adheres to the metal and the jute goes on the other side of the "ice and water guard"??

Yes, the "Ice and Water Guard" is just a sticky film... think of it as giant tape. It's a good idea to clean off the surfaces if there is any oil or dirt on the metal first, blast of windex works well...

The Jute is just a big piece of cheap thick clothe/blanket it doesn't stick by it's self, but you can use the 3M adhesive spray, I just kinda layed it up there and smooshed the door panel back on (door panel, interior trim, carpet etc...).

But you don't want the jute getting wet, because it will mold (I think?) you want to use the ice and water guard to seal out air from the outer panels, and place the jute on the side closest to the interior. What works well for heating insulation works well for sound absorption also... Ie. sealing the outside out keeps the air from transmitting noise, then it has to go through the jute to come in the car.



Q: Yeah, I'm trying to achieve weight on the doors but i also like the fact that sound will reflect better off of the aluminum. I'll pay for it. i know there are generic products with aluminum backing but I'm too lazy to find them
You're not going to get any sound reflection off that aluminum that you wouldn't already be getting off of your STEEL DOORS!

Here are some sound absorption coefficients for various materials... And the attached picture the two highlighted areas are plain and Aluminum backed fiberglass insulation... I've taken the difference of the absorption and the aluminum backing only makes a difference in the 250hz region... But the fact that you already have 2 door panels makes it moot... Not to mention the whole idea is to ABSORB sound, not reflect it... the only reason they have the aluminum on it, is because it withstands higher temperatures than plastic. In the original purpose of these materials they were meant to seal heat inside boilers, so aluminum was the product of choice instead of plastic. But when they applied this material to roofs and automotive purposes it became plastic because it makes a better water/heat/cold/temperature barrier than aluminum.

The 70X i.e 703, 705, 701 compressed fiberglass sheets are for home acoustical treatments, boiler liners, and duct lining (though honestly you don't really want fiberglass in a vent)... anyways, they have plain (no backing), plastic, and Aluminum backed. The only difference between the two highlighted ones, is the aluminum backing. You can see that at frequencies below 250hz (baritone singer) the aluminum will block some frequencies, but above 250hz it will substantially increase the noise reflected. these numbers are all percentages... so the difference (aluminum sheet) at 2000hz is -.39% meaning it's going to make almost 40% more noise than without it... The human ear is most "sensitive to the 800-2000hz range because that is the region where the human voice is (hence good reason to be more sensitive to it). So I reccomend the non-aluminum backed asphault sheeting.

________125_____250_____500_____1000____2000____40 00____NRC
Plain____0.11____0.28_____0.68_____0.9_____0.93___ _ 0.96____0.7
Aluminum_0.17____0.71____0.59_____0.68_____0.54___ __0.3____0.65
__________________________________________________ _____________
Differnce_0.06___0.43____-0.09____-0.22___-0.39___-0.66___-0.05


http://www.bobgolds.com/AbsorptionCoefficients.htm

If you really want that aluminum backing... do this. Get 2 bottles of the 3m Super adhesive (10$x2=20$) and a big roll of aluminum foil (5$) then glue it ontop of the Ice and Water guard, and you'll still be 40$ ahead which you can buy enough jute (which I highly reccomend for it's higher frequency absorption and cheapness) to soundproof your entire car.
(insert Chart1 here)
The point was to compare two identical products, used for sound absorption, one with the aluminum backing, one without. Subtract the two from each other and you get the equivalent of the aluminum reflections similar to what we are looking at.

If you want your music loud, buy better amps and speakers. Sound reflections are not the way to get it louder.

The important part is to make two sealed sections, one behind the speaker, one in front of it. That way you don't get sound waves cancelling each other out. The same could be said of poorly mounted speakers, with air escaping between the speaker mount.

Think of high end speakers... do they have sheet metal behind them? no, they have very heavy wood (sometimes lead lined) and some sort of foam or fabric.

The studio environment you speak of has lots of acoustical foam... The purpose being to disrupt waves from bouncing around the room, and secondly to absorb the noise.

In perfect sound testing environment, you would try to minimize the room and rely almost soley on the speaker. Our Cars are not a perfect sound environment, we have wayyyy too much glass, plastic etc.. (hard surfaces) that give too much reflections as is. A good sounding car will attempt to minimize those reflections.

And "reflections" is not what asphault sheeting is meant to stop. It does nothing for reflections. You need a soft surface like carpet padding or acoustical fiberglass sheeting (do some research, that's what the best theatres use) to stop reflections. reflections are only for higher end frequencies.

Anything that weighs will reduce resonance. Doesn't matter if it's poop or asphault sheeting. Feel free to waste your money on heavy crap.

I was joking about putting aluminum foil on there... maybe YOU didn't get the joke. The plastic door panel already reflects most of the noise from INSIDE the car... the point is that aluminum does squat for resonance. The Jute blocks outside noise. Lower you Ambient noise level 3db and it's the equivalent of making your speakers 3db louder. You want to block outside noise and only let your speakers play out of the hole they're supposed to.




edead, fatmat, dynamat original, grace and water guard are all the exact same stuff. The only purpose they serve is if you have alot of bass and want to stop the sheet metal from vibrating. It also will stop plastic pieces if you use this to tie them down with.

Any sort of mass dampening (i.e. above) will not stop any road noise. You need an acoustical absorbing material. Jute will do wonders.

You can spend 100$ on dampening and absorbtion (66$ for 109 sq. ft of Grace Ice and water Guard, and 44$ on Jute) and get 300 times quiter ride and better sounding acoustics than someone who pays 300$ for "show" asphault.

Honestly, I don't care what you use, the materials are pretty much the same, and I'm not sure what you're arguing about. If you go look at the data I provided, they'll show that the aluminum foil does provide some reflection. That was your point no?

I've gotten in many arguements with people about this. And you want to know what they all have in common? They already dropped alot of $$ on their "special" material and now have to justify to themselves why they did the right thing. Well, I'll tell you what, I've made the wrong decision many times, but my ego doesn't get in the way and try and disprove the truth... I feel stupid yes, but next time, I would take what I know and do things the right way.

So go get some empirical evidence about the aluminum layer if you don't understand mine. The fatmat quote is stupid, "thinner, lighter, yet 4x more effective"... you know what? what is the goal of the asphault sheeting??? WEIGHT. There is no other purpose to the layer than weight. Honestly, go check out some acoustics books or somthing.


So how do I start to install it?
Covering up the holes is an important part of sealing the external noises out. Air transmits noise, and especially in the doors, it makes a rear chamber for the speakers so air doesn't flow between the inner and outer chambers (skins per se)...

You basically add it on until you're satisfied that it's heavy enough not to resonante... I wrapped the door skins with my knuckles and you can hear the frequency that it makes go down as you add more asphault sheeting. I put some on the exterior panels (through the holes) and then covered the holes up and did a bunch on the door.

Do the knuckle rap test... if it makes a nice solid noise instead of a twangy noise... you're good to go. Imagine a saw, the old school ones you used to cut wood with... if you can imagine that sound, and adding weight to it, until it's resonating frequency is below a certain point, you have the idea of what you're trying to accomplish.

"Jute" is very light, like a blanket sort of...

I used the 3M adhesive spray and that held it very well, though in the floor I didn't use any, though now that I think about it, it might be a good idea. The 3M adhesive spray is with the paint stuff at home depot/lowes etc... comes in a big aerosol can, spray both sides, wait a bit for it to become tacky, stuff holds any and all fabrics great.

Jute like any good sound absorber has lots of air pockets which will encourage the growth of bacteria. Bacteria like plant roots love a moist but oxygenated substrate (surface to breed on). Actually the fiberglass I was referring to, which is made of sand/silicate; in Europe they use alot of Rockwool which is just basalt/granite based fiberglass... And if you know what rockwool is, it's the ideal hydroponic medium which grows plants in most major hydroponic Gardens which provide vegetables for us. So Jute, like Fiberglass and Rockwool inherently have great bacteria growing potential; but in themselves they're not going to melt or anything.

Just treat it like carpet, you wouldn't stick carpet in the engine bay or anywhere else that might get wet, jute is the same way. It's not going to mold if you have it insulated, that's why I like the cheap asphault sheeting to isolate moisture from outside the car door panels.

I was at Lowes this weekend, and noticed they didn't have any of the fabric type of carpet padding that I have found to work well... at some point I supposed they may give up on the nylon threaded carpet padding, it does pretty much suck for carpet padding, but does well for our purposes

would you say its as quiet as the acura tsx interior or a standard luxury interior? i'm sure it will be hella of an improvement of what i'm hearing now.

I wouldn't say it's as quiet as any luxury car necessarily, for the amount of work we do... i.e. luxury cars have the car stripped, including the dash out and seats, trunks... they can make air seals much better than our cars have. Also simply their materials weight more, thicker glass, thicker sheet metal etc...

Luxury cars as we know tend to be heavy and make up for it in bigger engines... our cars are more efficient, less power, lighter car... I don't want anybody to get their hopes up that they're going to instantly have a luxury quiet car, but you can probably cut the sound level inside the car by half. A little bit of work will make alot of difference.

Everyday I get into my car and appreciate less noise... took me 3 days of full work, but I did alot of things at the same time. Worth every penny IMO. I even convinced my wife to do the same after she heard the difference...


If you just did the doors and floor/rear seats you'd probably get alot of benefit. taking the headliner, rear quarter panels, and dash apart (in order of difficulty) will make improvements, but in diminishing quantity.

My friend's mercedes S500 has like 1/4" thick glass... (silent almost)

It's alot of work, but if you're already set yourself on sound dampening (dynamat etc...) why not throw some jute in there, make yourself a good seal with the asphault sheeting (i.e inner door skin and outter door skin) and then put some jute inbetween the panel and yourself...

I what I am trying to stress is the whole upper frequency part of noise reduction. Sure you could add 2" worth of asphault sheeting, but at that weight cost, you could have a sheet of jute or fiberglass which weighs almost nothing comparatively.


Conclusion of sorts:
High density fiberous materials are the best high frequency noise blocker. The problem with the fiberglass stuff is that it's very light... they make compressed fiberglass, but it's rigid and expensive.

The foam mixed carpet padding will work, but not nearly as well as the fiberous stuff... the open cell foam is what they use in expensive acoustical treatments that are bonded with some sort of vinyl or asphaultic sheeting... combined with an asphault sheet, it's very helpful. You want to avoid hard foams though, those will transmit noise like a speaker, Loose materials = better.

Do this, hold part of the carpet padding, whether it's foam or fabric and talk or yell into it... or just hold it near your ear and see which one sounds more "lively" i.e. which one sounds more dead... the foam I think will block some noise, but probably you'll hear more coming off of it than the fabric. With the compressed fiberglass sheets in home theatres, if you're ear is within a foot of the sheet, that ear sounds deaf, like almost no sound is being reflected from it at all... that should be what you judge a material, literally the sounds in home depot/lowes etc... all those high pitched noises, when you hold your ear up to it, which one makes them go away the best... I've wrapped my head in the jute before and walked around the store to prove it to somebody once... if you can make associations about the properties of materials, you'll have a very good head start when you decide where to put the materials in your car.



PRICE COMPARISON:
Grace Ice and water Guard
108 sq. ft = 66$ (for me a while back w/tax) picked up
Roll Length 11.0 m (36 ft)
Roll Width 914 mm (36 in.)
Roll Size 10.4 m2 (108 ft2)
Roll Weight 15.3 kg (33.6 lbs)
Thickness, Membrane 1.02 mm (40 mil)

Fatmat
100 sq. ft = 100$ plus shipping, with shipping = $129.98
Shipping Weight 31 Pounds
Installation Weight 23 Pounds
Thickness 45 Mil

That's $0.61 a square foot for the 40mil grace ice and water guard
That's $1.29 a square foot for the 45mil Fatmat

Difference? 5mil but that 5mil might be because Fatmat has an aluminum backing... Grace ice and water guard has a plastic one... Which one would you rather have? If somebody wants to do the calculations to compensate for the 5mil difference, be my guest, but 5mil is not 5mm 5 mil is like a piece of paper... and the grace ice and water guard weighs more anyways, and that's what you're trying to achieve, weight on the doors... in addition to also pinning plastic pieces down and joining undamped metal parts.


Data taken from:
http://www.na.graceconstruction.com...e=a&id=74&did=8
http://www.na.graceconstruction.com...d/GIWS-060J.pdf

and

http://www.fatmat.com/fatpaks/100.htm
Adhesion qualities of Grace:
Check out the Adhesion... 3 pounds per square inch on plywood. If the surface is dry, free of dirt and oils, should stick more than enough and not come off ever... if you stick it together, it ain't never coming apart.

PRODUCT DATA
Property Value Test Method
Color Gray-Black
Thickness, Membrane 1.02 mm (40 mil) ASTM D3767 Method A
Tensile Strength, Membrane 1720 kN/m2 (250 psi) ASTM D412 (Die C Modified)
Elongation, Membrane 250% ASTM D412 (Die C Modified)
Low Temperature Flexibility Unaffected @ -29°C (-20°F) ASTM D1970
Adhesion to Plywood 525 N/m (3.0 lbs/in. width) ASTM D903
Permeance (max) 2.9 ng/m2s Pa (0.05 Perms) ASTM E96
Material Weight Installed (max) 1.3 kg/m2 (0.3 lb/ft2) ASTM D461

 
Rep Power: 321

How much will i need if i do my trunk and front 2 doors? Or should i just buy the 62.5 sqf of RAAMat and do my entire car? I have Kicker 6.5" Components in the front, and Kicker 6.5" Coax's in the rear, i'm running a Kicker 350.4 for those and will soon be adding the sub/subs and amp with custom fiberglassed trunk install.

 
Rep Power: 0

D@mn popcorn, thats a long read!!!! I think I need to read it again cuz now I'm more confused.


Maybe I'll just spen the $0.68 per sq ft. and get the fatmat!!!

 
Rep Power: 370

Brown Bread is better then Dynamat

 
Rep Power: 283

I have just bought some dynamat and planning to lay it down sometime this week hopefully. I want to know what is the recommend amount of layers I should put of the dynamat xtreme. One layer for the trunk and one layer for the front doors or maybe two layers each? Anyone care to answer this for me please..

 
Rep Power: 328

I'd recommend fatmat just so you have a backing on it, kinda hard to roll the ice and water guard, as the coating on it's very thin plastic. Works great though, you just have to be careful. I like fatmat though, you get 100 sq ft for like $100 shipped, plus the cleaning solution mix, and a roller. It's a great deal, and what I use in several vehicles now. A word of warning though, I used about 50 sq ft in the trunk myself. Some stretch the 62.5 ft to the whole car, but I like every square inch covered. The girl that bought my civic was amazed at how deadened it was, and she's actually gotten my deadening work. it was my gf's sister. All her friends are amazed, and I've got a line, I just don't know if I'm ready to take on deadening cars in my spare time, too labor intensive...

 
Rep Power: 0

Using the RAAMmat quantities for reference and sedan that I have, 62.5 will do the trunk and front doors with a little bit left over. I used 3 rolls or 187.5 sq. ft. to do the entire car, but I mean ENTIRE. Pulled up the carpet, pulled down the headliner and both side of the interior plastic trim panels. Also covered it all with Ensolite foam.

No matter which product you choose here's how to install it.

1) Clean the surface that you are going to apply it to. My car was 2 weeks old when I did it so it wasn't too hard, but you want to vacuum up any dirt or fibers. Then use either acetone or denatured alcohol to completely degrease it. I used denature alc.

2) Peel back the first inch or so of backing paper and attach it to the surface. Then keep peeling and pressing the section of mat into place. This stuff is incredibly sticky and takes a little practice. It will happily stick to itself or the wrong place if you don't watch it. Once it sticks to something it is there for good. Once you get going it is pretty easy. You want no air bubbles and you want to press it down firmly with your hands and then go over it with a wallpaper roller. The asphalt based mats need to be pre-heated with a gun, which is one more reason not to bother with them.

3) Once you have a layer down on an area say a few feet square, start knocking on the surface with your knuckles. If it sounds hollow and "ringy", put another layer on top. Most areas will need 1 - 2 layers or 1 full layer with some smaller areas doubled up. Some may take 3 or even 4 layers. But once the area passes the knuckle test, any more is just a waste of mat.

If you want to put foam down it is pretty easy to do once the mat is in place. You want to be careful about how thick you go in places where trim is mounted. In most places, like the floor pan, you can go thinner on the edges and thicker toward the center. Just remember that the carpet and trim have to go back in.

 
Rep Power: 0

Popcorn and Rudy, I was planning on Fatmat-ing my car. Will a couple of layers reduce road noise?

Also, I should probably hook up my sub and listen for rattles and fix those before doing my trunk? or do this before doing my floor (underseats)?

 
Rep Power: 0

The sub test can help since that is what starts people down the "find the rattles" path. There are some classic rattle sources that you may address separately.

Rear license plate - mine only has two top screws so it rattled like a loon. I put mat and ensolite on the back of it and screwed it down tight.

Rear deck - rattled before I pulled it out and matted and foamed it. Quiet after that.

I don't have a spoiler, but that seems to be a problem for people.

The main thing you want to watch out for is sealing up an area that might rattle before you kill the rattle. There really aren't a lot of places that you can do this. One would be the latching mechanism in the trunk, but you wouldn't seal that up anyway. Just think twice before yo mat over any open space with metal or plastic parts inside. You should be OK going either way.

Matting will reduce road and engine noise, but not eliminate it. You are making your panels much denser which will reduce the amount of noise that can pass through - especial low frequency noise. Pay particular attention to your wheel wells, from the trunk and from the front seet foot wells - tire noise is going to be big there. They are also a good place to build up some foam since high frequency noise wants to be absorbed. A lot of noise comes through the doors so work hard there. Foam is real important in the doors since it prevents the reflections and standing waves that ruin the sound of your speakers.

It is tough to get to the firewall in our cars, so go as far up as you can. I'm still researching how to get a good hood liner installed.

One really good tip I can give you. This will take longer than you expect. I had a two day window when my gf was out of town and wanted to avoid the evil eye I knew I would get if she saw me tearing apart a brand new car. It ended up taking three full days, not including the doors or trunk which I wisely planned to do as separate projects - so I had some splaining to do It took me more than a day to get everything out of the car. At least I had the seats out of the living room before she saw that.

It is hard work and well worth it in the end, especially if you like to take things apart like I do. This is why I tell people to avoid cheap materials. It seems like a great way to save some dough, until you see how much time you put into it. You aren't going to want to do this more times than you have to, but you will want to do it to every car you own after you do the first.

Good Luck!

 
Rep Power: 0

Popcorn should write a book... damn dude that's alota info

 
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I know where my rattle is coming from but it seems like it won't go away. It is the latch in the trunk area. How can I fix this? I tightened it down but still won't go away

 
Rep Power: 328

Layering up stopping road noise?

mat deadeners serve a few purposes. Mass loading. Mass loading lowers the frequency required to vibrate the panel, thus causing the higher frequency waves to be absorbed. mass loading is what you do to keep the panels from sonically resonating. That's the main point of dynamat. Extra layers equals greater mass loading and requires the frequency to go lower to vibrate the panel. Is it possible to have a resonance or rattle free car? Not really, but enough so that you can't hear them.

 
Rep Power: 328

Dragon, did you move the latch to tighten the seal? Here's a few suggestions you should try. Completely remove the catch. You have a few options. I like to take a rubberized undercoating spray and slray the entire catch (don't worry, it'll still seal, and eventually it'll rub off where the release strikes it). Put a single layer of mat deadener behind it (remember to perforate for the screws to go through it). Buy some rubber washers and put them on the screw between the catch adn teh place it screws into, then put one between the screw and the catch.

For the latch, just make sure everything's tight in there, and maybe remove the plastic cover/casing thing.

 
Rep Power: 0

So, you're saying a few layers will reduce the road noise?

 
Rep Power: 328

I'd say a single layer will help, the more you add, the more it'll improve. Might not hurt to go under the car and add a layer of rubberized undercoating, if you have access to a lift of some sort.

 
Rep Power: 0

Hey popcorn, I got it to work last night. Here is what I did. I put some nylon "lock washers under the catch. That seem to do the trick also I adjusted the latch again to the first notch (again). Well either way it isn't rattling anymore. Does anyone know where I can get some Ensolite?

 
Rep Power: 0

I've only found two places:
Upholstery supply Yu want the MLC

I just order it from Rick I think he is cheaper, less than $10 per yard I think, 56" wide. He also sells a very good adhesive. I get 1 can per 2 yards. Email him with what you need, or what you want to do and he'll tell you what you need.

There are also several car specific foams - I know Dynamic and SecondSkin have them, but they are really pricey.