Sound Damping?

SBosco · **Posted:** Mon Aug 11, 2008 11:09 am

I am planning on installing an aftermarket sound system into my CRD KJ next weekend and was wondering what kind of experiences everybody has had with sound damping material (ie. dynamat). I am considering yanking out the whole interior and applying a layer of it to every exposed interior surface. I wanted to find out if anybody has tried this, what the results were, and any tricks or suggestions/advice anybody had. Thanks.

Frostednutz · **Posted:** Tue Aug 12, 2008 4:12 am

i did it and i don't regret it but i didn't find much of a difference until i muted the stereo when i was driving... no road noise and minimal rain drop clatter. if done correctly it will be louder in the cabin and quite er on the outside which is good if you don't want tickets but when you have a giant sub there's not much you can do. just do the door panels, rear wheel wells, rear cargo area, and transmission and i think it will make a big difference i know it has in my jeep. it's a long process and tools needed are size 45 torx for the seat belts (to get to the roof) 10 mm and a drill for the pop rivits in the rear cargo area. i forget the size of the seat nuts.

VTNomad · **Posted:** Tue Aug 12, 2008 7:45 am

I did it. It made a big difference. I used the Duplicolor brand. I still get a little odor from the material (its been several months sice I didi it), I let it air out for two days before reinstalling the interior. It's gotten much better, since I let it sit outside with the windows down, and is still getting better, I believe it will disappear eventually. I didn't remove the dash, door panels or drill out the cargo hooks that hold down the carpet in the rear. I'll do the doors when I add new speakers.

I can tolerate the smell, the wife hates it, I only notice it when the Jeep has sat somewhere hot with the windows up for a few days. Even then, I just crack the windows, crack the AC and its gone within 30 seconds.

I added Goodyear Wrangler Silent Armors the same day I put the interior back together. I didn't measure my dB beforehand, but I measure the dB in a friend's Renegade, and mine with the soundproofing and tires is about 4dB quiter, at highway speeds, than hers. I'm not sure how much of that is attributable to the tires. It was weird at first because it was so quiet. It felt like my Jeep was floating over the pavement. I had to turn my radio rown slightly.

To remove the interior:

Remove the seats
Remove the side panels
Remove the headliner
Reinstall in the reverse order

I think I used 10mm, 15mm, 17mm, 18mm sockets. A very large torx driver for the seat belts, a smaller torx driver for the EVIC, and sunvisors, a small socket (7.5mm) for the grab handles, and a philips head screwdriver for the center console.

I broke the bolt that holds the two sides spilt rear seat together. It had a large head, but a very small diameter threaded section, it extremely easy to over torque and $10 to replace.

SBosco · **Posted:** Tue Aug 12, 2008 9:00 am

All great feedback, thanks guys.

I called the auto parts store where I get a discount from and had them attempt to order me all the clips and retainers for the interior door panels and rear hatch. I figured that I would need to replace them all because, in my experience, they always break when trying to remove them. Anyway, they called me back and said even with their 10% discount from jeep dealership it would end up costing $120 just for the 4 doors and tailgate!!! How does Jeep justify charging over $4 for each one of those little plastic retainers/clips!?!?!

Do you think I'll need them all? Is there a better source?

Also, how much of a pain is removing the headliner? Do I need spray adhesive to reinstall it?

Is there any guide/tutorial about how to properly remove the liberty's interior?

I already did the tailgate with this new type of vinyl based sound deadening material called VB-2, from Cascade Audio Engineering:

http://www.cascadeaudio.com/car_noise_control/

http://www.cascadeaudio.com/car_noise_control/vb_2.htm

It's half the weight of traditional asphalt based sound dampening material with twice the damping. The best part...it doesn't smell, even when heated. It got really good ratings in an independent test:
http://www.sounddeadenershowdown.com/

VTNomad · **Posted:** Tue Aug 12, 2008 9:09 pm

The headliner is kind of a pain, but not bad. Once you have the side panels out, remove all the sunvisors, all of the overhead lighting, the sun roof trim if you have it and the rear seat grab handles. Above the drivers seat, part of the wiring harness is hot glued to the headliner. I pulled it off of the headliner and taped it to the ceiling.

The liner tends to bend at the rear grab handles. I slightly creased mine when removing it, but with it reinstalled the grab handles held it snug enough to remove the crease. You will need a buddy to hold one end up while you lower the other end. You'll have to elevate one side or the other because the liner is too wide to simply slide out of the back. It surprisingly rigid, except at the point of the rear grab handles.

SBosco · **Posted:** Wed Aug 13, 2008 10:09 am

Okay, I have decided to go ahead and order enough of the deadener to do the whole Jeep. How many square feet did it take you guys?

Also, how many clips/retainers do you think can be salvaged and how many should I order? Any other supplies I should acquire?

Thanks again for all of your help.

Frostednutz · **Posted:** Thu Aug 14, 2008 5:29 am

be careful and you can save all but 1. that one is on the very rear part of the headliner. it never hurts to have extra... you can always double or triple up (which i highly recommend). 100 sq ft should be enough if it's in your budget. take some measurements when you rip everything out if you're worried about the budget. also you can cover the inside of your subwoofer enclosure to increase db and maybe sound quality if you have a thin box.

SBosco · **Posted:** Thu Aug 14, 2008 9:02 am

Yeah, I can swing about $250 for the 100 ft^2. I think I'm going to order 2 retainers per door, 4 for the tailgate, and that one for the headliner...should run me about $50 :roll:

I will start this weekend but can only get so far because I currently have a limited supply of deadener and will be waiting on the shipment of the remaining deadener.

I'll try and take some pics as well.

My sub boxes are about 5/16" thick fiberglass with a 3/4" MDF top. Initially I vacuum bagged 7 layers of fiberglass cloth over the foam molds. That hardened and ended up being only about 1/16" thick; it's amazing what vacuum bagging will do. Now that I had a shell to build off of, I added fiberglass mat, fleece and a bit of carbon fiber, to increase thickness and consequently rigidity. I also used only epoxy resin rather than polyester resin so its really strong. To finish it off, I made a rabeted joint between the fiberglass and the MDF which increased the bonding surface area. So I don't think I need to coat the interior of the enclosures but can always add it if I find it necessary...thanks for the tip.

SBosco · **Posted:** Sun Aug 17, 2008 11:11 am

Posted pics of the enclosures here:

http://www.lostjeeps.com/forum/phpBB3/viewtopic.php?t=31257&postdays=0&postorder=asc&highlight=enclosures&start=15

Sound Damping?

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