First of all, I didn't know whether to place this thread in this forum or the Interiors forum , but I thought sound deadening material is mostly used for car audio purposes. Now thats outta the way.....

Does anyone have tips or advise concerning placement of sound deadening material? Did anyone have better luck at removing certain rattles by deadening a certain area? Where did you get the most change? Throw anything at me....any advice or tips would be great! Thanks guys.

Im planning to apply Dynamat Xtreme to an 05 Coupe and then throwing a bunch of nice SQ equiptment in....

 

Big flat panels are the best place to put dampening. This will keep them from resonating. Basically if you tap your finger on a panel and it has a tinny sound then you should put sound dampening there ie. inside rear qtr panels, insides of the door, and the roof. Panels with lots of ridges for reinforcement are not going to resonate as much as they are much stiffer.

You should also look at closed cell foam as it provides a barrier to block the rest of the sound that gets through. Second skin (overkill) and also raamaudio (ensolite).

If your going to do a bunch of nice sq stuff i would also recommend ditching the rear speakers. After going through a rear speaker install there are just too many fundamentally bad design decisions for the rear passenger speakers. It would take a lot just to get them to sound right. Also treat the heck out of the front doors if you are going to put your speakers there. Both in dampening and foam. Especially on the outer door skin. The inner one is also good to put dampening on as it provides a much more solid baffle for the speaker to mount on.

 

I can go into details if needed. I haven't done anything with my G, but I did a **** load with my Accord. I've used several different brands, ranging from eDead, Rammaat, Dynamat Xtreme and Second Skin.

Only two I'd recommend are Second Skin and Rammaat, in that order. Rammaat has the best bang for the buck, but Second Skin is the best product. The Damplifier mat is thicker than any other brand. Damplifier Pro is a step up. Difference between the two is pretty much 2 layers of Damplifier Pro = 3 layers of Damplifier, so less work and it's about the same cost (Damplifier comes out to be $4 cheaper, going by 30 sq. ft.).

Damplifier sticks very well and it also doesn't stick right away. What I mean by this is that if you mess up putting it in the wrong spot, it will come off without a problem and you can put it in the proper location. Once put on, you don't have to worry about it peeling.

I recommend doing the doors, and not just with one layer. I'd recommend doing the inner portion of the door with 2 layers, followed by a layer of Overkill. Behind the speaker, use the speaker tweeker kit. On the outer portion of the door, do a layer or two of Damplifier and between that and the door panel, use Rattle Pad.

The trunk is another location, the lid especially and if you want to go all out, do the rear deck and the trunk walls and floor. For the trunk walls and floor I recommend Spectrum, which is liquid based. It makes it easier if you use a spray gun, get theirs since it's big enough for the thick liquid that Spectrum is. I'd recommend doing at least one layer of Damplifier on the trunk walls and floor though.

For my trunk in the Accord, I did 3 layers sprayed Spectrum, and the lid i did 2 layers of damplifier, 4 layers spectrum, and 2 layers of sludge (super thick version of spectrum). It was solid and absolutely had no rattles, even with 3,000 to an 18" sub firing upward.

If you want to eliminate road noise, deaden the wheel wells and fender. I did that in my Accord and wow, felt like I was driving a luxury car. I did 3 layers of Spectrum and a layer of sludge, though I would have done more if I had more. I'd also recommend doing the firewall, both from the cabin and engine side, though that would be tough and if you're going all out. Do the floors as well and use Luxury Liner in addition to it.

For SQ, don't worry about rear speakers as previously mentioned. I'd also recommend doing tweeters in the A pillars for better imaging or do kick pods.

For the C pillars and quarter panels, fill the gaps with expanding foam, I recommend Big Gap Filler. Made a HUGE difference and eliminated some rattles.

Here's some things to keep in mind. There's rattles and there is vibration. They're different. For rattles, use an open cell foam like Rattle Pad. For vibration, use deadener. Rattling is when one object resonates and comes in contact with another object. Vibration is when metal resonates.

Oh, when you lay some deadener, get a roller. You want to make it stick to the metal as good as you can. Also, for the doors, cover the holes with sheet metal and cover those up with deadener. When you mount the speakers, lay some deadener between the spacers (or baffles) and the speaker, basically mount the speaker over it. And also seal the gaps between the baffle and the door with deadener.

If you have any questions, or if I don't respond here, feel free to PM me.

 

I did doors, rear deck (where 6x9s are), trunk lid, and trunk floor.