Soundproofing Education?

Hello,
I have just put money on a contract for a 2023 Offroad and trading in my 2021 sport. I never got around to soundproofing my 21, but always noticed how loud the road noise is and would say to myself that gee, I really have to get that done someday. Well, it is now high on the agenda of things to do to this new offroad.

Is dynamat the best or something else is better? Is it better to focus on only certain areas or is it better to go ahead and do the entire floor and doors? How good of a job can you do with soundproofing before added weight becomes relevant?

 

Soundproofing is done in layers. Heavy butyl is done in squares. It doesn't need full coverage, it's just there to stop the vibration of the panels. On top of that are layers of closed cell foam in two different densities. Neither are nearly as heavy as the butyl. There are plenty of online tutorials about this.

Now, let's talk locations. Doors. Doors are essential. Sound dampening the doors will knock out half the tire noise and a significant amount of wind noise. After that, do the back of the cab. Look up the "pool noodle mod." This is where most people stop, myself included. I did butyl, foam, and pool noodle on the back wall.

Hardcore people who want a true acoustic paradise that would win against the Mormon tabernacle itself will continue on. They'll do the floor pan next, followed by the roof. I'm impressed by these people. I chose to compromise and be happy with my "mostly there" reduction. Just doors and back wall, and my truck sounds like a typical sedan. It's not whisper quiet, but it's whisper quiet...for a truck.

In all, I spent about 30 pounds worth of butyl and who knows what in foam. Foam is the electron to butyls proton - it's negligent in weight but highly important in function.

 

https://resonixsoundsolutions.com/r...-deadening-material-independent-testing-data/

This link graphs & tests all the big hitters in multiple tests & comparisons, theres multiple tabs mid way down the page.....
Start studying....

 

Any good TW build threads that show this "mid-level" soundproofing solution? Pls. share.

 

I knew this would be the right place to bring this question. I will check out that link and i definitely appreciate hearing that 100% coverage isnt absolutely required.

 

I wish I could point to a single build. It's kind of scattered.

The butyl mat + foam top layer is pretty generic and can be found in most tutorials. Basically the butyl goes on the outer door skin plus a few small squares on the inner door skin (directly underneath the stock vapor barrier plastic):



The closed cell foam gets jammed between the vapor barrier and the door card (the plastic interior panel).

The pool noodle (personally I found that black pipe insulation works better) gets wedged between cab and bed; it sits on top of the frame right at the base of the cab/bedliner. Here.




There are a few threads about it. I thought it was silly when people first started reporting it. But it was three dollars to experiment, so I tried it. And by golly, it did reduce a lot of road noise.

 

Thanks, that'll get me started.

Re: the pool noodle, it makes sense based on standard architectural soundproofing practice. In a room-sized sound-blocking wall built to say, STC 55 or 60 (a standard wall is around STC 30,) a through-hole just size of golf ball can double the amount of sound leaking through. I.e. all it takes is a small gap to allow a lot of sound through, and that cab/bed gap is the only direct, open channel straight from the noisy (highly turbulent air, transmission, and exhaust noise) up to the cab rear glass and inside the cab.

I can see how blocking that would make a significant difference. I guess the downside is that it probably tends to trap rain, moisture, and random organic matter down in there over time, making it a potential long-term rust trap?

 

Resonix is fantastic stuff, run by good people. Lots of good information beyond the product too.
I did my roof, doors, back wall with their products. Did my previous cars doors and trunk, plan to use it on my project car when it comes time for it.

 

I kinda like the noise.

Keeps me awake.

Reminds me:
I wanna die when I'm asleep just like my grand-pappy....
Not like the screaming passengers in his car.

 

Amazon basic or nvx is a happy compromise...

 

Most proponents wave it off and say its fine; I personally prefer to drop the noodle and inspect the area every spring. I have not seen evidence of moisture or debris trapping, but I'm still going to take the few minutes to inspect it periodically.

 

May be able to use the rubber seal that comes on Ram trucks - part number 68309888AA. Kind of funny the Ram guys don't like the seal and remove it.

Edit: For those worried about the rubbing of paint may be able to use something like this instead:

$36 ESI ROK BLOCK Tailgate Gap Cover 4.25" width

https://www.amazon.com/BLOCK-Tailgate-Cover-4-25-width/dp/B00BPE4AP6

 

just my experience with the pool noodle. i installed it and thought i could maybe hear a difference for the year i used it.
i removed it and examined the paint as best i could and noticed some grime accumulating. doubtful there was any paint damage...yet.
since my hearing is diminished on the high end, but not terrible, due to age and stupidity, i have decided the very minor benefit was not worth putting it back and risking damage in a very inaccessible place. i don't miss it.
removing it showed it deformed very nicely to the ribs. it sealed pretty well, just did not result in the noticeable benefit i was hoping for (ie very little effort and noticeable reduction). 20 year old ears might disagree.

 

+1 for ResoNix. Not only do they make great products, but their support (and educational content) is top-shelf. Their prices stung a bit, but I figured if I'm going through the significant effort of application, might as well use top-shelf product. I lined doors (shell / trim panel) + rear wall with butyl, then used their fiber mats on rear shelves + door trims. The fiber mats were really the secret sauce for noise reduction in my application.

It was a lot of frustrating work, but I'm very pleased with the results. Much less road noise + tire hum, but more importantly for me my stereo sounds absolutely incredible.

The only thing that I still haven't solved are the rear vents flappin' when playing bass-heavy tracks loudly :/

 

There's a build thread where the guy put a ton of effort into this and took readings after each mod. he was even putting material in the fenders, etc. I'll edit and link if i find it.

I had great luck(for the money) in my silverado by putting down 2 layers of peal and seal and a layer of felt over it.


this one:

https://www.tacomaworld.com/threads/ultimate-sound-deadening-project.836242/