Firstly, a word about different products. There are two kinds of sound deadening – cheap and useless and expensive and effective. Many people chose the cheap option but it really doesn’t compare to the more expensive products. I would recommend to always go with Dynamat or Stinger sound deadening products. The reason they are expensive is because they work. Would you buy a Coles brand head unit or amp? So why skimp on the sound deadening which is just as important to good sound.
Anyway, I chose to use Dynamat so that’s the product I’ll use for this tutorial. It’s readily available, not stupidly expensive, but very efficient. I have seen (well, heard) the difference in using Dynamat first hand in my own car, so I know it works well. It costs around $30 a sheet and it took me about 1 and 2/3 sheets to do one door on the Getz. However, that’s with full coverage. They recommend that anywhere between 30 – 60% coverage is fine, so if you are on a budget, you can put a little less in. I choose to do it properly.
Dynamat works in three ways. Firstly, the foil creates a sonic barrier which transforms noise into silent energy. With the movement of the car, the energy normally resonates within the metal panels. The Dynamat stops this. Secondly, the tar-like sticky part that adheses to the metal adds weight to the panel and therefore also stops it from rattling. And lastly, the denseness of the tar stuff absorbs the random sound waves that come the wrong way out of the speaker so that you only hear the good stuff. They say using 15 to 30% coverage of Dynamat will decrease the noise in your car by 3db, and add 3db to the sound pressure level of your speakers. While I don’t know how accurate that is and it would depend on the car, speakers, etc, it does help.
Anyway, let’s get prepared for putting the Dynamat in. Make sure you have everything handy – ruler, sharpie and stanley knife. Of course, you also need to Dynamat. I purchased a box of it ($250 or so, cheaper than buying it by the sheet).
Next, we want the Dynamat to stick at well as it can, so it’s a good idea to clean off any residue, dirt, dust, etc. It’s a good idea to use grease and tar remover. This time I tried “De-solve it” a product made from oranges or something and it worked quite well. You’ll also need a rag to wipe on and a rag to make sure there’s no slippery bits.
Go around and give the metal a good rub with the rag (spray the cleaner on the rag, not the door) and then go around and clean off any residue with another clean rag. Don’t spend ages on this, the cleaner the surface the better it is to stick stuff on. I just gave it a quick rub down and it came up all shiny.
Now that it’s clean, it’s best to cut the Dynamat into strips. You have to get into the outer shell through the service holes, so it’s hard to do the whole sheet. Also I found there was a support bar in the way… To cut the sheet to the right size strips, stick a ruler inside the door cavity and get a rough measurement. It doesn’t have to be exact as the Dynamat is easy to mould around stuff. The best method is the cut and try method.
To start off, measure up the section you want to put a strip on. Then measure that out on the sheet with the ruler, marking it with the sharpie. No one will see the inside of the door, so don’t worry about marker everywhere. Cut the strip with a stanley knife (lie the sheet down on concrete like in the pic and then run the knife along it) and be careful not to cut yourself.
Now, while I think of it, if you’re doing this during the day and it’s not raining, chuck the sheets of Dynamat out in the sun. They heat up a little and it’s easier to mould them. Just don’t put them in the direct sun so they get so hot you can’t handle them.
Okay, now that we have a strip, place it into the cavity in the spot you want it to go. Leave the backing on the strip because you’re just making sure it fits before we stick it on.
If you’re happy that it does fit, peel the backing off it and then carefully put it back in place. You can smooth it onto the surface with a roller that’s sold by Dynamat, or you can just use your hands. For my money, I found my hands to be cheaper. Just make sure it’s as smooth as you can make it so it sticks well.
And then repeat until you’ve covered all of the outer shell (in my case) or 30 – 60% if you’re being a cheapass…
And that’s all there is to it!!
Now, put the trim back on by going in reverse of the above, and then do the other door. Then have a beer, pat yourself on the back and wait for the next installment of my tutorial.