Fiat 500 Forum banner

1 - 10 of 10 Posts

·
Registered
Joined
·
666 Posts
Discussion Starter #1
The car is out of the repair shop; first stop, new speaks. I had them leave the panels off... time for sound deadening in the sides.

Fiat is about average for factory sound deadening. That narrow light gray strip (top) is the deadening for the rear panels, followed by some padding and black styrofoam in the panel. It's not bad, but can be better.

Surfaces should be degreased. I used 91% alcohol, but would have used a degreaser if there were any residue. Here I applied 1/2 and 1/4" closed cell foam. (It works as a sound deadening and sound proofing material.) It is easier to apply in smaller pieces since the adhesive back wants to stick at first touch. Seams were sealed with Gorilla tape, so a perfect fit is not necessary. Interior sound deadening would require modifying the door panel.

back panel.jpg

The factory door has a 4" wide strip of the same tarred cloth, running 3/4 the length of the door. The flexible Styrofoam "paper" and the 6" black Styrofoam block completes factory sound management and gives the door the reassuring thump when closed.

The cube and liner were tossed, and closed cell foam was used to line the door skin. I figure 50% was covered, due to the collision bar and factory deadening.

Dynamat is the leader in sound deadening material. I researched, then compared samples, and found Noico is a knockoff. It uses the same 80 mil butyl, a tar like substrate that doesn't harden like the tar based stuff. It has a diamond pattern in the aluminum backing, making it easier to see where it's been rolled. This is same material that seals windshields in place. Its best use is on flat panels, but it's what the pros use. Doing it again, I'd probably go with a rubber backed product. (Replacing a window regulator will be messier with this product.)

On the driver's door, I created a template and carefully precut everything. That's a waste of time. On this panel I simply cut the sheet to 23", peeled back the top couple inches of paper backing, and rolled the material at the window sill. Then I could use scissors to trim access to the panels snaps. Around the speaker, I cut a square. Once done, I pulled the remaining backing and rolled it down. Then I could use the scraps to fill in the gaps and around the speaker. It requires 2 sheets to do each door, thus the Gorilla tape sealing the pads together.
door.jpg

Door panels in place, it's 5 lbs heavier than stock and has a more solid thump when closing the door. Mostly, it helps block noise and vibrations and the door acts as a speaker cabinet, improving sound quality from the speakers. I used 16 ounce bottle of rubbing alcohol (91%), a few paper towels, a tape measure, a box knife, scissors, and a rolling tool to install. (A straight edge was useful for cutting panels, and cardboard to cut it on.) Removing the door panel required a mini-screwdriver (pulling plugs), a torx and a phillips screwdriver. The panel popped off easily, but I used a panel tool.

I ordered the 36 sqft pack of Noico from Amazon and used 4 of the 9 sheets. $66, plus the $6 roller. The closed cell foam is scraps from a previous job, "XCEL Extra Large Marine Roll, closed cell neoprene rubber with adhesive." Those rolls are 16 x 60 x 1/2 @ $24... way too much product for this small job. Gorilla tape has a longer lasting adhesive than standard duct tape and the small roll was about $5 at my home improvement store.
 

·
Registered
Joined
·
1,339 Posts
That silver material, is that a good replacement/substitute for the thin foam liner that comes from the factory? I’m wondering just because I had to cut that when I fixed the door handle, and I know that sheet foam is also a moisture barrier...
 

·
Registered
Joined
·
666 Posts
Discussion Starter #3
I think you are talking about the Noico in the door picture. All those products are waterproof and have much better sound deadening than factory. However, the Noico (and Dynamat) use butyl rubber. This is a soft, tar-like material, without tar's stink. I was told it would remain soft, but the samples I saw on demo were hard. (Maybe Dynamat used a different material to keep customers from sticking to the demo bell.)

Later removal will be more difficult than the factory sheet. If you aren't after the sound deadening, and yours can't be taped, I'd probably use Visqueen. It was used for years in cars. The glue (if enough didn't remain on the door) can be picked up at shops that sell automotive products... like paint supply houses. With Visqueen you could apply dabs of glue on all the high points on the door, instead of just around the perimeter.
 

·
Registered
Joined
·
117 Posts
Hi, MAP, how do you rate the panel dampening a month later? Has the interior noise level been reduced?
I have an app on my iPhone, DecibelXPro, and I measure 75-83 dB at highway speeds. The pavement is either new asphalt or 15 year old concrete, with some variance on other roads.
And, do you think the leftovers would be enough for another 500 job? Are you selling them? I am interested in this same project.
 

·
Registered
Joined
·
223 Posts
I was just wondering ... instead of insulating inside the door, what would be the effect if you insulated the panel? That would be easier to do wouldn't it?
 

·
Registered
Joined
·
666 Posts
Discussion Starter #7
I had a problem with my old dB meter, so am not sure of original sound levels. It was reading 82 dB factory, then died but I think it was maybe reading low. I had to approach half volume on the stereo to hear what people were saying. After removing the rear seats, it was even louder.

Lining the rear deck brought noise down to around 80 dB. (It would be quieter with seats installed.) After lining the doors and hatch, with minimal lining in the quarter panels, sound is reduced to 78 dB. (Measured at 60 MPH, stock tires, noisiest road.) Much of the noise is low frequency tire noise, which is harder to block.

Yes, lining the inside door panels would be easier but I did it this way for better audio and max sound deadening. This way the door works as a speaker enclosure. As a side effect the car is a bit cooler. The factory door insulation "Styrofoam" was removed in the doors but left in place for the quarter panel covers.

I am considering removing the centers of the quarter panel covers and making a flush panel. This would allow room for speaker box(es) behind the panel. This would allow for better insulation, better quality stereo (more bass), without intruding into the passenger area. I think floor deadening would reduce noise levels. I have some aftermarket floor linings arriving on Monday, so will see if that's enough, or if I'll need to pull the front seats.
 

Attachments

·
Registered
Joined
·
12,566 Posts
I always seen the installation of Dyamatt sound deadening, placed on the inside of the door panel. To cut down on road noise and heat. Providing damping to the outside sheet metal. Enhancing the structure of the vehicle. Less vibration from sound system speakers. Same, for the cars floor, and the inside roof. At least that what they do on the cars shows, on the Motor Trend channel.
 

·
Registered
Joined
·
666 Posts
Discussion Starter #9
Yes, Dynamat, Dynaliner and Dynapad is used on professional installs. The products I used are, IMO, slightly superior and less expensive. Mat is used over flat surfaces to minimize vibrations. (Flat panels work much like a speaker, amplifying vibrations.) Pad is 1/2" thick "rubber" to absorb noise and heat, and Liner is a thinner version. Doing it again, for heat, I might have used Mat first, then covered that with Pad, on the outer door skin... instead of just using Pad.

Applying Mat to the inside panel seals the door cavity and improves sound quality... much like a speaker enclosure. It is thin enough that there is no problem reinstalling the door panel. Some installers (like Crutchfield) recommend installing inside, others outside, so I combined the techniques.
 

·
Registered
Joined
·
11 Posts
+1 for sound deadening. Added this after I removed the rear seats on my car (some people care about the added weight) and it was much better.
 
1 - 10 of 10 Posts
Top