haven't decide yet what type of audio upgrade to do, but wanted at the same time to reduce the amount of road noise

I'm considering 2 options

#1 using sound deadening materials in the doors and covering the trunk area.

#2 using sound deadening materials for the doors, the trunk area and inside of where the stock sub and glove box are

wondering if anybody could comment on the reduction of road noise with either option

thanks

 

I did #2, it took alot of work but the results are fantastic, much quieter interior and a much more enjoyable ride. Stereo sounds much better, too.

 

I just did the floor and sides of the hatch and the strut tower bar in the rear and it made a world of difference. The Bose sounds even better now! Could use a sub, but hey, thats another story. Also, when you take apart the inside of the hatch you will see your air vents that let out air and equalize it. They have two little flaps on each one. I set them up to stay halfway open at all times. I could hear them flapping and it drove me nuts. It's really quiet back there now. It even eliminated buzzing of the plastic parts due to the aftermarket exhaust.

 

I went to a roofing supply house and picked up some dynamat-clone stuff (rubber base with aluminum top. Peal and stick.) I did the doors, the hatch (didn't remove the panels, just all the bare metal I could find under the spare) and the sub area. The audio quality definitely improved. Base is tighter. But I still get a lot of road noise on highway cement (asphalt is ok).

Anything else I could do to really quiet the car down?

 

dynamat - clone stuff called ice-shield ?

If im thinking of the right stuff, did you notice a smell to it, sorta chemical like ? I plan on using that instead of dynamat, as its much cheaper and looks dont matter behind panels.

 

FYI. The stuff with the alu layer is not nearly as good at dampening. The real power of dynamat and similar materials comes from the fact that it is "loaded" vinyl. For the material to be effective it actually has a oily base to it. This loading really helps. For this reason a small piece of dynamat placed at the center of a door panel could be far more effective than a large sheet of the wrong product. There are a number of materials made for commercial use with this property, but the minimum quantities are far to large for consumer purchase (expect for dynamat). It is widely used in industrial applications and things as varied as locomotive cabs etc.

 

The stuff I bought did not have a brand name attached. The roofing supply store was for contractors, thus the product came in bulk. But it is rubberized asphalt, and asphalt is derived from oil - so I would think the properties would be similar.

I thought the way that Dynamat works is by making the panel thicker and heavier, which then makes it resonate at a lower frequency. That gives it sound Deadening properties, but not sound Insulating properties (I believe there is a difference).

 

I also applied several coats of liquid FatMat as an undercoating to all 4 wheelwells before doing the interior. It was very effective at reducing road noise, and it quiets those pebbles that get kicked up by the tires.

You can find liquied FatMat at www.fatmat.com, it's $60 a gallon, goes on like thick paint, and dries to a flat black. A very good mod if you want to reduce road noise.

 

thanks for all the tips.. i'll cross check them with what the audio installer reccomends

 

ezee - did you just use 1 gallon for all 4 wheelwells? Any pics?

 

I used VB3 from Cascade Audion Engineering. Works great.
http://www.cascadeaudio.com/prod/vb3.html

 

Sorry, no pics. One gallon was enough to apply 2 thick coats to the outsides of all 4 wheelwells and the inside of the doors. Then I applied 2 more gallons around the hatch area, mostly above the muffler, the strut brace, and the insides of the wheelwells.

The interior is very quiet now, very little road noise and the stereo sounds much better. Also, the price on liquid FatMat has been reduced to $50/gallon.

Some tips if you're thinking of using the liquid: it doesn't stick to smooth painted surfaces too well. It sticks to the painted metal of the interior much better if you prep the surface by roughing it up a bit with steel wool or sandpaper. Once the first coat has dried then you can layer it on just like thick paint, just let each coat dry overnight before applying the next coat.

I also used masking tape to cover the exposed nuts and bolts, then I removed the tape after the final coat. When applying to the outsides of the wheelwells I covered the brakes rotors with newspaper to protect against drips. While it's wet the liquid cleans up easily with water, but I didn't reuse the brushes, I used a new 3" brush for each coat at the cost of $3-$4 each.

 

ezee- did you paint the liquid fatmat over the existing areas in the wheel well that seem to have some sound deadening material?

 

fLYBYZ--or anyone for that matter--


"They have two little flaps on each one. I set them up to stay halfway open at all times. I could hear them flapping and it drove me nuts. "

Does anyone have pics or direct me to where this is and how I can get to it?

 

Yes, I left all the original stuff in place and painted right over it.

 

But did you paint on any other areas or just over the area that already had stuff?

 

I applied the FatMat EVERYWHERE behind the seats, including the wheelwells, strut brace, glovebox and subwoofer areas (I can no longer hear the fuel shoshing around), everywhere except the ceiling because there is no noise coming from above, only from below.

Everything behind the seats has been coated. When I had the trim out I also replaced all the speakers and installed a BaseLink, which by the way sounds great. I figure 3 gallons of FatMat added about 20-25 pounds to the car's weight, but the ride is so much quieter it was well worth the effort and expense.