How noisy is your TJ really?

When I bought my '05 Unlimited, I pulled everything out of the interior and had the inside of the tub Line-X'd. HUGE difference in noise reduction. As an added bonus, the interior is pretty much indestructible. The Unlimited comes from the factory with an under-hood blanket, and the rear carpet has 1" of sound deadener, so when I'm running the hard top with full doors it's amazingly quiet. When I get a chance I'll run a sound meter and see just how quiet.

Dyna-mat and other sound material is pretty expensive to do the whole interior, before spending the money I'd definitely recommend looking into Line-X or something similar. Plus you can hose the interior out if you need to.

Before & After:

LineX1.jpg
LineX2.jpg
 
RubiconMike said:
When I bought my '05 Unlimited, I pulled everything out of the interior and had the inside of the tub Line-X'd. HUGE difference in noise reduction. As an added bonus, the interior is pretty much indestructible. The Unlimited comes from the factory with an under-hood blanket, and the rear carpet has 1" of sound deadener, so when I'm running the hard top with full doors it's amazingly quiet. When I get a chance I'll run a sound meter and see just how quiet.

Dyna-mat and other sound material is pretty expensive to do the whole interior, before spending the money I'd definitely recommend looking into Line-X or something similar. Plus you can hose the interior out if you need to.

Before & After:

View attachment 62462View attachment 62463
Click to expand...

The Line-X looks really nice. Perhaps the PO took mine out, but I have neither the added padding in the rear or hood blanket (only 50k miles and no mods, so seems unlikely they’d strip those out). Do you know if the Rubicon Unlimited would be different than a non Rubi?
 
rasband said:
The Line-X looks really nice. Perhaps the PO took mine out, but I have neither the added padding in the rear or hood blanket (only 50k miles and no mods, so seems unlikely they’d strip those out). Do you know if the Rubicon Unlimited would be different than a non Rubi?
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Interesting:

I don't know, mine's a Rubicon Unlimited also. My '03 Rubicon had the blanket under the hood, but not under the rear carpet. The sound deadener in the rear cargo area of mine is part of the carpet, not a separate item - is your rear floor carpet as thin as the front? Did yours come with a hardtop or soft top? I wonder if that would make any difference.

I'd be interested to hear from other Unlimited owners, both Rubi and Non-Rubi: Did your Jeep come with a sound deadener blanket under the hood, and is there sound deadener material under the rear carpet? Did yours come with a hard or soft top?
 
My noise is from the Tires, I don't hear the engine over 15 mph. Makes shifting by sound impossible.

Tigerman said:
Hi all,

I took some noise level readings while driving the Jeep to see what contributed the most and least to the noise level. Would you be able to do the same so we can quantify and compare?

Test vehicle: 1998 4.0 TJ with full doors and factory hard top.

Phone: Samsung S8

1. 70 mph, freeway, under power: 74/75 dB
View attachment 61469
2. 70 mph freeway, coasting in neutral:
69 dB
View attachment 61470
I am deducing that engine under power adds extra 5dB.
3. 35 mph on the street: 70dB
View attachment 61471
Wind noise from going 35 mph vs 70 mph 4, 5 dB.
4. Stopped, idle: 60 dB.
View attachment 61472

5. Engine off: 39 dB
View attachment 61473
Wow, the largest contributor in my configuration is the motor!!! Not the wind. It adds 20 dB.

Conclusions:
Motor sound is the largest contributor at 20dB.
Idle motor vs under normal power +5dB
Wind noise increases liniearly and at +10dB at 70 mph calculates to +0.14dB/mi.

Your biggest concern is the motor so engine compartment and firewall sound proofing should have the largest impact.

What are your numbers?
Click to expand...
 
With a soft top and hard doors. 4.0 manual with 33" all terrain tires , I'm 72 decibals at 63 mph with fan on the second setting .

I installed an asphalt sound deadener from home Depot , found in the Roofing department , for 35 bucks , thoroughly , to the tub from seat forward .

It is awesome.
 
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AndyG said:
With a soft top and hard doors. 4.0 manual with 33" all terrain tires , I'm 72 decibals at 63 mph with fan on the second setting .

I installed an asphalt sound deadener from home Depot , found in the Roofing department , for 35 bucks , thoroughly , to the tub from seat forward .

It is awesome.
Click to expand...

Hey Andy, can you post a link to the "asphalt sound deadener" at Home Depot? When I search for that I end up with a roll of "90 mil Premium Peel and Stick Crack and Sound Membrane" for $189.

Thanks,
Rob
 
Robnfl said:
Hey Andy, can you post a link to the "asphalt sound deadener" at Home Depot? When I search for that I end up with a roll of "90 mil Premium Peel and Stick Crack and Sound Membrane" for $189.

Thanks,
Rob
Click to expand...
Hey man , I don’t have a link ....but the product is sold only in roofing and gutter ....u.s. seal is the manufacturer , and it 12.5 square feet I think for 16.87. It’s foil coated and has a yellow wrapper ...6” wide rolls.

I saw guys using it on you tube for cars ....it’s essentially the same thing as Dynamat....works fantastic.
 
AndyG said:
Hey man , I don’t have a link ....but the product is sold only in roofing and gutter ....u.s. seal is the manufacturer , and it 12.5 square feet I think for 16.87. It’s foil coated and has a yellow wrapper ...6” wide rolls.

I saw guys using it on you tube for cars ....it’s essentially the same thing as Dynamat....works fantastic.
Click to expand...

Ok, I found it on their website. Thanks!
 
jjvw said:
I'm driving around this morning and trying the app out.

Engine off 49-51db.
60db parked at idle.
78db at 3000rpm parked in neutral.

Today I have the hard doors with the windows rolled up. Some highway driving at 60mph. No rear windows. I haven't seen anything louder than 78db.
Click to expand...
jjvw said:
To add to my data...

78-79db at 75mph

There were a couple brief spikes into the low 80s, but I didn't notice what caused them. Ambient noise is my best guess. The Jeep noise is pretty steady and consistent.
Click to expand...
The hard top went on today.

77-78db at 75mph.

It's odd, because the cab is noticably quieter. I guess the loudness is nearly the same, but there is less ambient noise like wind and outside traffic.
 
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jjvw said:
The hard top went on today.

77-78db at 75mph.

It's odd, because the cab is noticably quieter. I guess the loudness is nearly the same, but there is less ambient noise like wind and outside traffic.
Click to expand...

Really interesting--no change then. I am hoping to put mine on today and take readings in the morning.
 
jjvw said:
The hard top went on today.

77-78db at 75mph.

It's odd, because the cab is noticably quieter. I guess the loudness is nearly the same, but there is less ambient noise like wind and outside traffic.
Click to expand...

THat's what I meant when I noted that most noise is not from the wind but from the engine :)
 
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Tigerman said:
THat's what I meant when I noted that most noise is not from the wind but from the engine :)
Click to expand...
I suppose this is the noise difference between a bunch of screaming children and just one screaming child.
 
tworley said:
Honestly I notice no sound difference. Though the minute i started driving I could feel the weight difference.
Click to expand...
When I put mine on yesterday, the side windows were in, but the rear was wide open. Each step in closing off the outside decreased my perception of noise, but the decibel readings all stayed about the same. It's really interesting.

I noticed the weight difference too.
 
Has anyone posted readings for no doors, no top on the highway?
 
jjvw said:
When I put mine on yesterday, the side windows were in, but the rear was wide open. Each step in closing off the outside decreased my perception of noise, but the decibel readings all stayed about the same. It's really interesting.

I noticed the weight difference too.
Click to expand...

I'm wondering if my smittybilt soft uppers contribute noise. One has a slice from theft, and neither fit underneath the hard top towards the rear. They seem sealed well enough, but maybe not
 
I have found this topic somewhat interesting also.
I too have been disappointed in the noise when driving my LJ at speed.
2006LJ Hard top & full doors with BedRug throughout.
I decided to do the sound test both before and after getting new tires.
I expected my Cooper MTPs were the biggest problem with noise.

MTP KO2
Engine off 18db
Idle 43db
30mph 62db 59db
50mph 63db 60db
70mph 81db 72db

It is like driving a different vehicle. Now I can hear the wind noise at 60mph and exhaust tone.

Next will be some kind of sound mat under the BedRug and the same test.

Thanks to the OP for all the good information and starting this thread.
 
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