Rockwool in your doors?

Curious: I know you can use rockwool on the outside of your house for exterior insulation and reducing thermal bridging, but wasn't sure how it would work installed in a vehicle door. Rockwool is moisture resistant, but haven't researched how much so. I can see some huge benefits of a proper installation: greatly reduced road noise, improved acoustics within the door panel, obviously be thermal insulation, etc. One would have to insure it doesn't interfere with the window of course.

There are several types of this insulation, ranging from loose and lofty to dense and stiff. Safe N' Sound is a common one I see a lot. Would be rather worthless to try and attach to the skin of a door, but some of the Roxul 60 or 80 boards might work. Unsure of how to adhere it best to the skin of a door, but if you could, it would work really well I'd bet.

Anybody tried this before?

Moisture resistant doesn't mean moisture proof. If you're going to do something like that in a door with roll-down windows, you'd want to encapsulate it in some heavy plastic. Several people have use rigid fiberglass wrapped in heavy-mil plastic and taped on the edges.

I used some roxul rockboard 60 in my last car and this car I'm doing now. I cut it in half so it's about one inch thick and placed some across the top, middle, and a thicker piece behind the midbass. It's wrapped tight in 1 mil plastic drop cloth to keep the moisture off of it. Attached to door with 3m super 77 spray adhesive and some HVAC ducting tape. Attachment 7305

OK, looks like I know what I must do then!

What differences did you notice by doing this?

I'm using two layers of 1" Roxul AFB in my passenger door. I randomly placed scrap pieces of mlv between the layers and wrapped the whole thing with 3.5mil plastic sealed with gorilla outdoor tape.

Here is a link to more info and my vein attempt to measure it's impact: https://www.diymobileaudio.com/forum...all-plots.html

I recently put 19 squares of Focal Black Hole Tiles in my driver's door also. I have no measurements to back any thing up but I will say the Roxul/mlv sandwich does seem to do a better job then the Black Hole Tiles. I only say this because the mirror on the driver's door still dances violently with heavy midbass while the mirror on the passenger door does not. I can also feel, with my hand, the door trim panel vibrations are less on the passenger door.

I put about an inch thick layer of Safe N Sound in my doors years ago thinking it would have some sound absorption properties too. It is held in place with some chicken wire. I can't say for certain I hear a difference, but I certainly think it sounds better since I put all the work into it : )

I checked on in a few years after installing it and it's still in good shape without obvious mold or water problems. I did make sure it was hydrophobic by dunking some in the pool before I installed it though, so maybe that helped me get lucky with not wrapping it in plastic like others have done.

https://photos.smugmug.com/photos/i-...-B9jtrxw-L.jpg

I can't say for sure I heard a huge difference before and after but it's certainly helping some because it is absorbing some frequencies and helping that metal door become anechoic. I'm no expert but I feel like it may help more in a two way setup where the door speaker is playing up to 2-3khz than in a 3 way where midbass is only playing up to 300hz. Either way, I have a bunch of this stuff laying around anyway so I just throw it in there.

would wrapping up the insulation hurt its ability to properly absorb rear waves?

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Originally Posted by The A Train

would wrapping up the insulation hurt its ability to properly absorb rear waves?

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Try putting a plastic shopping bag in front of your ear and see how much sound it will block (spoiler alert: not much). Similarly, wrapping rockwool in some plastic won't make it less effective.

The user keep_hope_alive is an acoustics engineer and swears by plastic-wrapped insulation in the doors

https://www.caraudiojunkies.com/show...ll=1#post16355

cms983,

Anechoic chambers are great for testing drivers. Music listening not so much, preferably, not at all.

I’m also a huge proponent for absorption wrapped in plastic. Made a huge difference in clarity and also I believed helped a lot of backwave issues and door car energy along will sealing the doors well.

https://uploads.tapatalk-cdn.com/201...87cfef14.plisthttps://uploads.tapatalk-cdn.com/201...db700b09.plist


Sent from my iPhone using Tapatalk Pro

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Originally Posted by Queef

cms983,

Anechoic chambers are great for testing drivers. Music listening not so much, preferably, not at all.

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He's talking about making the inside of the doors anechoic not the cabin. Pretty sure it would be a good thing in the door.

Anechoic = sucking out everything after initial response.
In a vehicle the antinodes couple making output "more" . Lowering resonant frequency of doorskin is desirable to get rid of vibrations.

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Originally Posted by Justin Zazzi

I put about an inch thick layer of Safe N Sound in my doors years ago thinking it would have some sound absorption properties too. It is held in place with some chicken wire. I can't say for certain I hear a difference, but I certainly think it sounds better since I put all the work into it : )

I checked on in a few years after installing it and it's still in good shape without obvious mold or water problems. I did make sure it was hydrophobic by dunking some in the pool before I installed it though, so maybe that helped me get lucky with not wrapping it in plastic like others have done.

https://photos.smugmug.com/photos/i-...-B9jtrxw-L.jpg

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I just want to say. What a beautiful door to work on.

Quote:

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Originally Posted by Justin Zazzi

Try putting a plastic shopping bag in front of your ear and see how much sound it will block (spoiler alert: not much). Similarly, wrapping rockwool in some plastic won't make it less effective.

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If the plastic is soft enough it would allow most mid and bass through, but the higher frequencies would bounce right off the plastic. The rockwool works by allowing the air to come in, and then get “tangled up” in the diffusion and the “limpness”. Although the difference may not be considered substantial, there would be a difference.

Hi, This looks like your first post here? Welcome to the forum!

At some level you are right, there would be some difference. You might be able to measure it with a microphone. But would you be able to notice the difference after it is installed inside your door?

If you can, come work with me and teach me how.

If there was a video on this topic it would be so much better.