Added sound insulation?

Has anyone added extra sound insulation to the interior of their XJ? I notice the fuel pump area is particularly noisy...I suppose someone could just add more insulation under the carpet.

Anyone tried it? Any writeups on it?

knottshawk said:

Has anyone added extra sound insulation to the interior of their XJ? I notice the fuel pump area is particularly noisy...I suppose someone could just add more insulation under the carpet.

Anyone tried it? Any writeups on it?

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Still working on it (should be right now, in fact). No official writeups for jeep that I could find on any of the forums when I looked, but I'm not the only one who has done this.

There are several paths you can take, and no "right" answer. I went all out
(well, for me. You could go even more nuts if you tried). Based on my experience, I would skip the step in picture 2 (liquid deadener) if I had to do it again. I would also recommend using Secondskin Damplifier or Raamaudio Raamat. Stay away from peel'n'seal, fatmat, and edead: http://www.sounddeadenershowdown.com/

The first layer is Secondskin Damplifier
The second layer is Secondskin Firewall
The third layer is http://www.acousticalsurfaces.com/noise_barrier/bardec.htm?d=14
It's the same thing as Secondskin Luxury Liner or B-Quiet V-comp, but less expensive if you're willing to buy the whole roll.

So can you not buy that third layer stuff? Their website doesn't have any "prices" links.... How much was your total cost?

knottshawk said:

So can you not buy that third layer stuff? Their website doesn't have any "prices" links.... How much was your total cost?

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I paid about 350 shipped for a 54"x30' roll. You would have to email or call them for a quote. They also sell a 20' roll, which should be enough to do the whole jeep from firewall to tail. I expect to have about 10' left over, but when I purchased, I was considering doing the roof. Once I actually hefted the material in hy hands, I realized there was no way I was going to trust a3m super90 adhesive to hold a 40 lb slab of vinyl above my head, and used ensolite MC foam instead.

If you don't want a whole roll, you can get it by the linear foot here: http://soundproofing.org/infopages/flooring.htm

The stuff weighs a little over a lb per sqft. - shipping is a significant portion of the cost of a sound deadening project.

My total cost for all sound deadening materials and shipping is around 1100. I intend to have a very quiet jeep.

You don't have to be as adventurous as I was. You could certainly just go to a carpet store or home depot and pick up a roll of carpet padding.

You can find ensolite, which is very lightweight, by the roll at http://www.skandiaupholsterysupplies.com/

It is nowhere near as effective as the heavy stuff of course.

Whats the white stuff?

langer1 said:

Whats the white stuff?

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Secondskin Firewall. Latex base loaded with vacuum filled ceramic beads. Presumably similar to Cascade TG and HyTech SC#1000. Supposed to be an excellent insulator against heat and noise.

Did not notice an appreciable difference in noise, and the tranny tunnel still gets hot enough to cook on.

Also, while it does adhere to painted metal, it doesn't stick a whole lot better than a post-it. (except that once you break the bond, there's no sticking it back). I may just be paranoid, but even though the paint itself is waterproof, the bond is bad enough that I would worry about erosion from the back if water had access to a free edge. I wouldn't use it inside doors, on the exterior of the vehicle, or anywhere in a rig that I planned in submerging.

Shortly after I ordered mine, the product was supposedly reformulated, I guess to use more ceramic and less glass filler. It may just be that I had higher expectations than the product could deliver, but there's that little voice in the back of my head that wonders if I didn't fall for snake oil (usually I'm pretty good about that sort of thing). In any case, I would not spend money on this product or on any similar product until seeing some unbiased test results and comparisons.

lilredwagn said:

Secondskin Firewall. Latex base loaded with vacuum filled ceramic beads. Presumably similar to Cascade TG and HyTech SC#1000. Supposed to be an excellent insulator against heat and noise.

Did not notice an appreciable difference in noise, and the tranny tunnel still gets hot enough to cook on.

Also, while it does adhere to painted metal, it doesn't stick a whole lot better than a post-it. (except that once you break the bond, there's no sticking it back). I may just be paranoid, but even though the paint itself is waterproof, the bond is bad enough that I would worry about erosion from the back if water had access to a free edge. I wouldn't use it inside doors, on the exterior of the vehicle, or anywhere in a rig that I planned in submerging.

Shortly after I ordered mine, the product was supposedly reformulated, I guess to use more ceramic and less glass filler. It may just be that I had higher expectations than the product could deliver, but there's that little voice in the back of my head that wonders if I didn't fall for snake oil (usually I'm pretty good about that sort of thing). In any case, I would not spend money on this product or on any similar product until seeing some unbiased test results and comparisons.

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Wow, very ambitious project. That must be your Jeep on the Second Skin forum?

Is it back up an running yet? How do you like it? I did a 1/2-assed attempt to cut the road noise by adding an extra bit of carpet pad in the storage area behind the back seat. Then I picked up some rubberized undercoating and hit the insides of the door skins pretty heavily. This actually did help quite a bit, I don't have the stereo turned up as much anymore and the sound is much better. I'd like to try some more of something, but I think I'll focus on making the exhaust a little more toned down (Flowmaster 70 & 2 1/2 pipe), if I can get it a little toned down it will help a lot, but I don't want to sacrifice performance so it's a balancing act.

Some of the things that have REALLY made a difference though was removing the roof rack rails (crossbars, rails are still there if I need them) and replacing the clutch fan with an electric. I was surprised how much difference that made.

Will I'm looking for something to improve the sound from some outdoor speakers with a metal housing. They sound tinny but otherwise good.

Lilred.... If you had to choose between the Damplifier layer and the third layer, which would you do? I can't afford both. I'm thinking of doing the damplifier and then buying some extra carpet padding or some local open cell foam to add to the carpet padding....

SCW said:

Wow, very ambitious project. That must be your Jeep on the Second Skin forum?

Is it back up an running yet? How do you like it? I did a 1/2-assed attempt to cut the road noise by adding an extra bit of carpet pad in the storage area behind the back seat. Then I picked up some rubberized undercoating and hit the insides of the door skins pretty heavily. This actually did help quite a bit, I don't have the stereo turned up as much anymore and the sound is much better. I'd like to try some more of something, but I think I'll focus on making the exhaust a little more toned down (Flowmaster 70 & 2 1/2 pipe), if I can get it a little toned down it will help a lot, but I don't want to sacrifice performance so it's a balancing act.

Some of the things that have REALLY made a difference though was removing the roof rack rails (crossbars, rails are still there if I need them) and replacing the clutch fan with an electric. I was surprised how much difference that made.

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yup, same nick over at ss forums. It's still looking about like it does in the last pic in my OP. I was able to put adhesive under most of it yesterday, but didn't get near what I wanted done because I can barely move my head - I think I got a sore neck from bending over wrong while scrubbing all of the interior trim on Fri eve.

Definitely saw the most improvement with the vinyl barrier, and most of that with the section up by the firewall and passenger floor. Of course, there's currently a hole in the firewall blocked off only by a piece of cardboard, so I'm sure that had something to do with it. Everyone says the doors make the biggest difference and I haven't even taken those apart yet.

I think what started this all was that after 2(?) years I got tired of my Magnaflow. I went to Midas and told them I was sick of it, and wanted QUIET. Whatever they put on toned it down some, but definitely not stock. It's alright around town, but it bothers me on the highway. My personal experience was that the muffler had not effect on performance, but ymmv. Thanks for the tip about the rack and fan- I'll have to check those out.

langer1 said:

Will I'm looking for something to improve the sound from some outdoor speakers with a metal housing. They sound tinny but otherwise good.

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Outdoor speakers outdoors, or in your jeep? What kind of metal housing, and how are they set up?

knottshawk said:

Lilred.... If you had to choose between the Damplifier layer and the third layer, which would you do? I can't afford both. I'm thinking of doing the damplifier and then buying some extra carpet padding or some local open cell foam to add to the carpet padding....

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Tough call. I saw a result with both. The barrier was a more noticeable difference, but it was on top of two other layers of material, so the effect may have been synergistic. If I had to pick one or the other, I would probably go with the barrier material for the floor of the jeep.

However, everything I've read about sound deadening always says you will get the most noticeable results from doing the doors - and you don't want to use open cell foam in the doors. I haven't done mine yet, so I can't comment on the difference. To keep costs down, you may want to consider using damplifier in your doors and adding just barrier or just carpet padding to the floor. Might want to budget for a can or two of 3m super90 spray adhesive at $12 a can, depending on how flexible the padding is.

The jeeps actually come from the factory with a foam/vinyl barrier on the firewall, so you wouldn't have to take apart the dash and do the firewall area like I did, just up to (and maybe a little behind) the mat.

Great looking project. What is the status on the XJ now?

BTW I would recommend closed cell foam over open cell foam. Closed cell is used typically in athletic and packaging applications. Unlike open cell it won't suck up water and moisture. Open cell smells ones it becomes damp...

FRAM said:

Great looking project. What is the status on the XJ now?

BTW I would recommend closed cell foam over open cell foam. Closed cell is used typically in athletic and packaging applications. Unlike open cell it won't suck up water and moisture. Open cell smells ones it becomes damp...

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It's still apart. The dash and carpet are back in, but none of the trim is. I still haven't done the doors.

I definitely agree about the closed cell foam. It should never ever be used inside doors or anywhere else prone to water (which is everywhere in a jeep.

However, I seamed up all that material in the first pics like so:


...and then hit ALL the seams and edges - including drainhole and bolt cutouts - with GE Kitchen & Bath Silicone II - with the exception of the very top of the rear wheelwells. I had already gone through 5 tubes when I ran out there, and decided that if the top of the wheel wells got submerged, I would have bigger problems than moldy carpet smell

Also, I removed the stock jute behind the carpet and replaced it with the same ensolite foam I put on the roof. While that will prevent moldy carpet smell, I think the jute is better at absorbing sound, and the fit is better too (the foam causes the carpet to be a bit puffy and not go well around corners).

I didn't take any pictures, but if you really want to see my caulk ...

wow ive been looking for this! Do you have any pics of the rear hatch im looking to sound deaden but not this extent. Probably some floor and def the hatch due to rattling from speakers. I was going to use Edead but you said dont use it. Whats the reason? just curious. thanks and great pics def going to help me out a lot.

sorry just noticed the date well coming up from the dead lol. If you are done the project how is it?

The new edead is butyl, so it should be better than the last version, which was just peel-n-seal. After reading through some forums, I did not get a good impression of ED with respect to any of their products. I went with Secondskin because Anthony had several times recommended a competitor's product to people on a budget, and I felt that this indicated not only honesty over marketing, but a confidence in the quality of his own product. There are plenty of people happy with their peel-n-seal, but as this is a permanent installation, I did not want to chance it. Incidentally, the product he recommends to those on a budget too tight for damplifier is RAAMAT. IIRC the difference between the two in price was not that great.

The jeep is definitely much quieter. The fuel pump is rather audible at times, and it's still definitely a jeep, not a cadillac.