Noise Control Project

[4xFUN]

I'm on day 3 of actually laying down Kilmat. I have lined the firewall and front footwells over the tunnel, left front kick panel, left rockers back and up the rear fender, and left B pillar.

I went overboard and I'm blaming it on you. You mentioned the door seals seemed to let lots of noise in. I saw lots of noise with my meter around the door seals as well. After looking at the door jambs, I think they were worth insulating too. But man, what a pain. I removed the harnesses and all the components on the B pillar. Also, the front kick panel has a shape like a speaker cone that I'm sure is the perfect road noise resonator, so I lined it as well.

Very impressive attention to detail and look forward to your feedback when finished! I am sure your hard work will pay huge dividends in reducing cabin noise. Do you currently have a headliner? They do really help, especially by trapping some of the higher frequencies that would otherwise be reflected.

As soon as the rest of the JL Audio gear (had everything on hand but then decided to order a second Stealthbox and a dedicated sub amp) arrives, I will also be dissecting my interior. In addition to upgrading the audio, I will also be adding various sound damping materials and replacing the door panels, top dash, console lid, brake lever and the red dash bezels with leather...I like the leather interior but wanted cloth seats, much nicer in Arizona summers when hopping in and out on trails-especially for girls who typically wear shorts or sun dresses here in summer

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[roaniecowpony]

Well, this is going slower than I thought. I used to be sorta fast. Well, maybe half fast.

At almost 2 weeks. I'm within an hour of finishing the aluminum/butyl damping layer. But, I ran out of material. Some more should be here today.

I only have a few square feet left to cover of mostly flat in the cargo area. Then I'll cover in Dynaliner foam absorbing material.

 

[zouch]

i ended up installing the Sound Assassin strips a week or 2 before i got around to finishing the Hothead Headliner install, and was impressed with how much the SA Strips took down the wind noise. didn't notice nearly as much of a reduction after installing the rest of the Headliner kit, but it sure looks a lot better!
coming from another J**p on MTs, this one doesn't' seem that bad.

 

[roaniecowpony]

Good thing we're on a stay at home executive order. But I'm making progress.

I finished covering the tub with Kilmat about as close to 100%as I could.
The B pillars are reassembled and only need the covers installed.


All the wiring is reattached to the rockers.

I've covered the front footwells and tunnel with 1/4" Dynaliner and I have front carpet down and the console installed and wired.

The rear footwells are also covered with Dynaliner on the flats all the way back to the rise in the floor to the cargo compartment.

It should go pretty quickly from here.

 

[roaniecowpony]

Of course, I finished and have the JL back together. I have driven it a few hundred miles, including a couple hundred on a trip up the state a hundred miles or so. The noise level is noticeably lower. It was a comfortable level on the trip. I have not taken a meter reading to compare to the reading I took prior to modifying it. However, it is lower enough to begin hearing other noise sources. Most notably is the drumming of the hardtop from flexing in the middle, when bumps in the road trigger it. I'm working on a solution for that. I'm also considering the CoverKing hardtop liner.

 

[4xFUN]

Of course, I finished and have the JL back together. I have driven it a few hundred miles, including a couple hundred on a trip up the state a hundred miles or so. The noise level is noticeably lower. It was a comfortable level on the trip. I have not taken a meter reading to compare to the reading I took prior to modifying it. However, it is lower enough to begin hearing other noise sources. Most notably is the drumming of the hardtop from flexing in the middle, when bumps in the road trigger it. I'm working on a solution for that. I'm also considering the CoverKing hardtop liner.

Nice! That was a hell of a lot of work, your attention to detail on this project was amazing!
Do you have any headliner now? The CoverKing looks like another great option...

 

[sf5211]

Omg I think I’d rather puncture my eardrums than do all of that work. Lol.
Just kidding RCP, that’s a beautiful job, I give you all the credit in the world.

 

[roaniecowpony]

Nice! That was a hell of a lot of work, your attention to detail on this project was amazing!
Do you have any headliner now? The CoverKing looks like another great option...

Thanks. We were locked down here in CA, so a covid project was better than watching Oprah. I don't have any headliner at this time. One of the other members here lined his top in Kilmat 50 mil then installed the Coverking liner. He reported very noticable results. I plan to do the same. But right now I'm upgrading our home PC/Monitor and spending a ton. Although I have no steady income, per se, being retired, my wife still has the idea that spreading out expenses means something. LOL. Besides, I need a break from rolling out Kilmat.

 

[Mike921921]

When you had everything apart, any interesting discoveries or 'ah ha' moments? Inquiring minds you know.....

 

[HeavyUser]

This is so ridiculous, I LOVE IT! Looking forward to before and after decibel readings!!

 

[roaniecowpony]

When you had everything apart, any interesting discoveries or 'ah ha' moments? Inquiring minds you know.....

No real big ones.

I did note that there are a number of central patches of sound deadening from the factory. They are the common asphalt patches that have been used by Detroit since at least the 60s. It's cheap, it's effective. If you are familiar with the JK (at least the early JK), you'll note that they have quite a bit more road and engine noise than the JL. Jeep put some effort into sound deadening the JL. The doors have a sound deadening patch in the center of the door panel that really changes the door noise. You can see the asphalt patches on the floor, in the picture below.
Also, Jeep didnt put any of the felt insulation, common in most street cars, under the carpet, in keeping with the theme that you can remove the carpet and rinse and drain the floor. Both of the products I installed will still allow for that, since neither will absorb water and I kept the drains accessible.

 

[Cuyose]

That's incredible work, and I can't knock that. But the difficult truth is the sound reduction is not going to be anywhere near what you would expect from the attention to detail and craftsmanship you put into your project.

I was amazed that taking the top and doors off made things so quiet at city speeds. The killer thing with the Jeep is the unavoidable wind whistles at seems that are necessary to allow all the cool things it can do.

Most of what you are doing seems to be to deaden road noise, which ironically is the only thing I notice that is new when I take top and doors off that I didn't hear with it buttoned up.

 

[Windshieldfarmer]

That's incredible work, and I can't knock that. But the difficult truth is the sound reduction is not going to be anywhere near what you would expect from the attention to detail and craftsmanship you put into your project.

I was amazed that taking the top and doors off made things so quiet at city speeds. The killer thing with the Jeep is the unavoidable wind whistles at seems that are necessary to allow all the cool things it can do
Most of what you are doing seems to be to deaden road noise, which ironically is the only thing I notice that is new when I take top and doors off that I didn't hear with it buttoned up.

Road noise is mostly affected by tire choice and tire wear. This is a cool project but I suspect the payoff may be limited by other factors.

 

[roaniecowpony]

Guys, all noise control efforts will have limitations due to space, weight, economic, and labor, and existing noise levels.

I've avoided doing a similar project in my trucks for years, due to the labor effort. It wasn't insignificant. But I had a good attitude going in. I didn't care about a deadline nor did I work on it when I didn't want to. I also wanted a project for our latest lockdown.

Are the results worth the effort? For me, yes. But if you have your doubts about it for yourself, you should not attempt this.

I can tell you I am very pleased every time I drive it. Ymmv.

 

[roaniecowpony]

...

Most of what you are doing seems to be to deaden road noise, which ironically is the only thing I notice that is new when I take top and doors off that I didn't hear with it buttoned up.

I put in two different materials. A sound deadener and a sound insulation. The butyl/alum material and the complimentary Dynaliner closed cell foam.

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