Rudeboy

I don't know anything about RattleTrap. To be honest, I've had so much trouble with that whole Corry, PA crowd - FatMat, Sound Destroyer, R-Blox, that I don't even bother talking to them anymore or even ordering products from them to test. Sometimes their customers send me samples and I'm happy to leave it at that. For all I know, RattleTrap could be decent stuff. "Patented Rubberized Compound" almost always means asphalt, but who knows? Love to see a patent citation though As a company, FatMat seems to know almost nothing about the products they sell. A perfect example is the "1 Mil PSA(Pressure Sensitive Adhesive)". This is a spec they apparently lifted from the old Dynamat Original without realizing that the manufacturing process used on products like FatMat and RattleTrap makes it impossible to have a distinct PSA - the asphalt or butyl is the adhesive. I also use the term company very loosely since it is a husband and wife selling the stuff out of their house. Try one of the tests I suggested and let us know what you find out. I don't mean to be snide, but where did you hear eDead v3 was better than Dynamat or RAAMmat? I know for a while ED reps were trying to spread the word that their new mat was better than Dynamat Xtreme, but they seem to have gotten tired of having me follow them around explaining why that was just one more false statement in a long line from them concerning their sound deadeners. In any case, liquids can be about as effective as mats, but I think it is safe to say that they will never be better than a mat with a decent foil layer. As far as eDead specifically, it is OK, but not super impressive. I've been testing liquids for the new version of SDS I'm working on. Of particular interest is the fact that it has a higher water content than several other products, making it a poorer value than it would seem by just comparing cost per liquid volume. What you really care about is cured weight - water is cheap and the ess you have to pay to ship, the better. If you are looking at liquids, consider Second Skin or Lizard Skin. Cascade may be good as well - I haven't seen any yet, but their entire sound deadening line is nice. I've seen a sample of the new version of Spectrum about to be released by Second Skin and it looks really impressive.

You can tell pretty quickly if it is asphalt or butyl by dropping a small piece in an ounce or two of mineral spirits. Wait 15-20 minutes. Asphalt will dissolve and turn the liquid brown. Butyl will either do nothing or break apart into black particles. If you aren't that patient, take a Bic lighter and try to set the adhesive side on fire. Butyl will burn after 10 seconds or so, asphalt will just melt. I don't believe you should ever use asphalt products in a car. Butyl deadens by adding mass, stiffening and internally by converting vibration to minuscule amounts of heat because of its viscoelastic properties. Asphalt is not viscoelastic so you lose one important function right off the bat. Asphalt melts at a low temperature. Rubber compounds are added to the asphalt to increase its heat tolerance. Unfortunately, the rubber breaks down over time and with exposure to temperatures much lower than is required to melt the composite material. Eventually the asphalt will melt at much lower temps than it did when new. Obviously this isn't a 100% guaranteed occurrence, just like smoking a pack or two a day isn't guaranteed to kill you. In any case, I've had hundreds of e-mails from people who have had asphalt products fail and exactly zero from those using butyl. Because asphalt is so much less effective than butyl, you will probably get the similar results without the risks by using much less butyl product. If you are going to buy $100 of asphalt, buy $100 dollars of butyl and spread it around. Finally, asphalt out-gasses toxic VOCs. So, asphalt is risky, ineffective, a poor value and poisonous. Seems simple to me

All good ideas. You can get to a point where additional vibration damper doesn't do anything because, well, the panel isn't vibrating anymore. It's not generally a good idea to just keep adding uniform layers - tap on the panel and listen for resonant areas. Build up the deadener in the areas that need it. The closer you get to a bend or weld, the less benefit you get from applying material. Another possible explanation for the change you hear in your subs is that you used to hear harmonics in the resonating panels adding higher frequencies and directionality to the sub's output. Take that away and it will definitely sound different - better, but different.

Treating from inside the vehicle is going to be the most effective, but if you have done that and still want to reduce engine noise, adding some material to the hood can help. If your hood has a stock liner, about all you can do is pull it off, add some vibration damper to the sheet metal and put the shield back on. No idea how much improvement that will bring. If you're looking at raw sheet metal, vibration damper then a product like Second Skin's Motor Mat or Dynamic Control's Hoodliner can be very effective. Engine noise comes through the hood and the windshield. Catching it at the hood can make a difference. While you're in the engine compartment, look at the firewall to see if it might benefit from some work - very vehicle dependent, I've actually got sound deadening in the fenders

Couple of points on this. Expanding foam is really useful for filling voids and locking panels to each other to prevent flex and resonance. You want to be very careful which type you use. You want the polyurethane varieties, normal or minimally expanding. Be very careful with the latex versions that stay soft. The absorb moisture and can cause rust where they touch sheet metal. Beyond that, The tightening everything in sight is a good first step whether or not you have the dough to go all out with sound deadening. Nothing worse than sealing a rattle in. The first step in proper deadening is a vibration damper like Dynamat Xtreme, Damplifier, RAAMmat, etc. These work by adding mass to lower the resonant frequency, stiffening the panel which actually raises the resonant frequency and by dissipating vibration via internal stresses. The last is the viscoelastic damping you here about. Asphalt is not viscoelastic, so it can never provide this important function. I also cation people to be very way of individual claims of success with asphalt. Many, many people have had serious problems including melting. Proper installation procedures can improve initial adhesion, but nothing can guarantee long term success. Ironically, the very act of heat asphalt mat to make it stick better reduces its long term stability. Batches of asphalt are very inconsistent and there is no way to pre-judge the outcome. It is a very risky undertaking. In point of fact, you can get equal results with MUCH less butyl mat, so it isn't even cheaper. You really need to get the vibration damper right up against the sheet metal, so it isn't really worth doing anything they will prevent you from doing a proper job in the future. I suggest waiting.