Has anyone install sound deadening for the front half of the cabin?

[I'm Tony Danza]

Curious if anyone has installed sound deadening for the front half, up the firewall as much as possible without dash removal? I am aiming to cut down on low frequency road noise, which is just exponentially worse on a lowered car with larger wheels (obviously). I won't mind the weight from MLV, as this particular Stinger is more of a "looks over speed" cruiser.

If yes, did you notice an improvement in lowering low frequency general road noise?

 

[G70LEbyAdoom]

@byebyeSTI has I do believe.

 

[byebyeSTI]

Curious if anyone has installed sound deadening for the front half, up the firewall as much as possible without dash removal? I am aiming to cut down on low frequency road noise, which is just exponentially worse on a lowered car with larger wheels (obviously). I won't mind the weight from MLV, as this particular Stinger is more of a "looks over speed" cruiser.

If yes, did you notice an improvement in lowering low frequency general road noise?

i have fully sound deadened the stinger , up as far as i could go on the fire wall and every part of the rest , with 2 layers some places 3 , and a lot of spray and memory foam in the rear wheel wells , as well as foam based deadner above the wheel well plastics ,, makes it a new car , est lower inside doors and under the rear seat and trunk , i used resonix products for the job

 

[StingaGT]

I installed kilmat on all doors and trunk area. Also, sprayed 3M rubber undercoating around wheel well and I love the result.
so much reduction in road noise

 

[Aarvix]

You won't have much luck with road noise below 1khz or so without throwing a ton of mass that the problem.
I see so many people saying that just CLD makes a huge difference, and exactly zero evidence to back that up.

I took measurements in my build thread, and while there was a big difference in road noise, it's all in the upper frequencies (still totally worth doing).

The doors made a huge improvement in blocking outside noise (adjacent cars).

The wheelwells made the biggest difference for tire noise.

I saw nearly no difference after doing the floor, and it was by far the most work.

Build Log - Sound System Upgrade

Been taking bites at this build for a while now, thought I might share it in case it helps other stinger owners, and and see if anyone has any comments/suggestions/advice. The car: 2019 KIA Stinger GT2. This is my daily driver and I've already put 50K on her. The HK system is pretty good for an...

stingerforum.org

 

[I'm Tony Danza]

i have fully sound deadened the stinger , up as far as i could go on the fire wall and every part of the rest , with 2 layers some places 3 , and a lot of spray and memory foam in the rear wheel wells , as well as foam based deadner above the wheel well plastics ,, makes it a new car , est lower inside doors and under the rear seat and trunk , i used resonix products for the job

Did you notice a decent reduction in front end noise or mostly doors/rear? Did you spray the entire inside of the plastic wheel well liners (not the road facing side)?

You won't have much luck with road noise below 1khz or so without throwing a ton of mass that the problem.
I see so many people saying that just CLD makes a huge difference, and exactly zero evidence to back that up.

I took measurements in my build thread, and while there was a big difference in road noise, it's all in the upper frequencies (still totally worth doing).

The doors made a huge improvement in blocking outside noise (adjacent cars).

The wheelwells made the biggest difference for tire noise.

I saw nearly no difference after doing the floor, and it was by far the most work.

Build Log - Sound System Upgrade

Been taking bites at this build for a while now, thought I might share it in case it helps other stinger owners, and and see if anyone has any comments/suggestions/advice. The car: 2019 KIA Stinger GT2. This is my daily driver and I've already put 50K on her. The HK system is pretty good for an...

stingerforum.org

Great write-up! Given your dB chart and comment, I may just start with the wheel wells instead of the floor/firewall and see how it goes.

About your front wheel well coverage...Did you just cover the back half of the front wheel wells? If yes, any reason not the front half?

And would the combo of Thermozyte plus a 1/16" MLV be the best bet for tire noise and wheel echo? Would adding a bit to the metal frame of the wheel well make any difference?

 

[Aarvix]

Definitely put deadener on the wheelwells. Anything to lessen the vibrations in the sheetmetal should help.
As byebyeSTI said, resonix is by far the best, but quite expensive. I used Dynamat Xtreme.

MLV is a sound blocker, but it needs as near to 100% coverage as possible. One good analogy I read is to imagine your neighbor is mowing their lawn outside. If your windows are closed then most of the sound is blocked, but crack the window even a tiny bit and it gets much louder.
The front wheel liners have a giant notch around the suspension, so frankly I have my doubts that MLV will do anything here, but I guess there's no harm in trying. The rears are much easier to get good coverage.
There's also a giant cavity behind the driver side wheelwell, definitely stuff it with something.

Honestly the best thing would be to use 3M acoustic thinsulate (not the stuff in your jacket) instead of thermozyte. It's expensive but has better noise reduction coefficient. The stock wheelwells actually have small patches of it already. Most auto OEMs use it, so I'm considering just going to a junkyard and grabbing some from the "quiet" cars like Lexus/Mercedes/etc. There's likely a bunch behind the door cards and above the headliner.

Notice in the graph below how quickly the performance drops in lower frequencies. Absorbing bass takes lots of space or lots of mass, it's up to you how much weight and money you want to throw into this project. As a point of reference, my MBRP exhaust drone is about 150hz.

Even though my tires still have most of that low frequency roar, killing the whine was a huge QOL improvement.


ps: I also added MLV to the interior wheelwell liners.

 

[I'm Tony Danza]

Definitely put deadener on the wheelwells. Anything to lessen the vibrations in the sheetmetal should help.
As byebyeSTI said, resonix is by far the best, but quite expensive. I used Dynamat Xtreme.

MLV is a sound blocker, but it needs as near to 100% coverage as possible. One good analogy I read is to imagine your neighbor is mowing their lawn outside. If your windows are closed then most of the sound is blocked, but crack the window even a tiny bit and it gets much louder.
The front wheel liners have a giant notch around the suspension, so frankly I have my doubts that MLV will do anything here, but I guess there's no harm in trying. The rears are much easier to get good coverage.
There's also a giant cavity behind the driver side wheelwell, definitely stuff it with something.

Honestly the best thing would be to use 3M acoustic thinsulate (not the stuff in your jacket) instead of thermozyte. It's expensive but has better noise reduction coefficient. The stock wheelwells actually have small patches of it already. Most auto OEMs use it, so I'm considering just going to a junkyard and grabbing some from the "quiet" cars like Lexus/Mercedes/etc. There's likely a bunch behind the door cards and above the headliner.

Notice in the graph below how quickly the performance drops in lower frequencies. Absorbing bass takes lots of space or lots of mass, it's up to you how much weight and money you want to throw into this project. As a point of reference, my MBRP exhaust drone is about 150hz.

Even though my tires still have most of that low frequency roar, killing the whine was a huge QOL improvement.


ps: I also added MLV to the interior wheelwell liners.

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Appreciated. So I have been looking into the Thinsulate idea and it looks fantastic. However, I am curious as to if using it on the front wheels is the best idea? I know it's hydrophobic, but maybe it could trap too much moisture in there, causing further problems down the line?

Resonix has a waterproof option, their Blackhole tiles, but they seem a bit thick.

Maybe I am sounding picky and overthinking it, but I don't want to half-ass this It's tough to find decent solutions/results for front wheel wells that are open to the salt/water.

 

[Aarvix]

That's a valid concern, especially if you live somewhere where they salt the roads (TX doesn't).

There isn't much space between the liner and sheetmetal, so you're gonna have to decide for yourself whether to run that risk. I think CLD is pretty safe, the butyl sticks so well I don't see any way for water to get trapped underneath it.

FWIW, the OEM rear liner has some kind of thinsulate-like material from the factory.

 

[globalrebel]

For someone who is just looking to quiet down the noise a bit, but not tear apart the entire car flooring and such . . . Are the simplest spots the rear trunk area where the battery is and then under the rear seat?

I'm really just looking to cut down on noise without spending an entire day doing this lol.