Looking for an opinion on putting sound deadening mat on my 80. The door has the structure beams that float just above the outer shell. Should I put the mat under it as far as it will go and leave it (i.e. cut into two pieces and basically have a gap under the structure beam), or should I then wrap a third piece on TOP of (around) the beam, effectively covering the entire area? I’m a little concerned about water going under the mat if I don’t do this, but then again with proper rolling and so on I think it should be sealed well enough. Just not sure what the “proper” way to do it is.
Sound deadening question (1 Viewer)
- Thread starter t00manyuserz
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I just sound deadened my 80 with resonix CLd on the doors and trunk. On the doors I did a hybrid of both methods you described, fwiw. I stuck the pieces below that horizontal bar as close to the bottom of the bar as possible.
For the pieces above the bar I tucked the material as best as possible into the narrow spot between the top end of bar and outer door skin but left enough slack to drape over around one half of the circumference of the bar.
My reason for doing this, rightly or wrongly, is to mitigate vibration while also minimizing locations for trapped moisture. The first objective certainly means applying deadening across gaps, and the bar to skin contact is certainly one of those. I’ve seen pros install butyl rope between the crash bar and door skin. The material I used is butyl based and I used 40ft2 across 4 doors and trunk floor.
The material I chose was resonix cld. I selected that product despite the cost because a) it’s one of the few products whose web site actually had remotely scientific measurements of its product performance, and also had the heaviest butyl weight per square foot (1 lb) and also came in a self adhesive form that was easy to cut, peel and stick.
Since installing this product along with new door weatherstripping and seals, my interior noise at 65mph has dropped from around 75-76 DB to 69 DB. Decibels are logarithmic so the sound energy halves every 3 db. This means my truck is now 1/4 as noisy as before. And this is prior to applying any sound deadening to the firewall or passenger area floor and roof.
Hope this helps!
- Thread starter
- #3
That’s interesting - thanks for the writeup. As best I could tell, the skin doesn’t actually contact the bar except at weld points, so I’m not sure if force inserting behind the bar is needed or not, and I’m also unsure if the bar actually vibrates or not… which is where I’m a bit stuck. Water certainly will drop from the window though. So I almost wonder if completely covering that whole area will be helpful as it’ll isolate the metal from any possible moisture (though I can’t do a perfect job as the ends are hard to reach, so there WILL be open areas on both extremities).
Amazing on the sound reduction btw. I’m not sure I’m going to do the floor because that means removing the whole interior and I’m lazy, but my sunroof leaks so the headliner needs to come down, and then I might just do the roof. I should probably do the door weatherstripping while I’m at it.
By the way, side question: when you bought the weatherstripping, did it come with the little plastic clips or were those separate?
Amazing on the sound reduction btw. I’m not sure I’m going to do the floor because that means removing the whole interior and I’m lazy, but my sunroof leaks so the headliner needs to come down, and then I might just do the roof. I should probably do the door weatherstripping while I’m at it.
By the way, side question: when you bought the weatherstripping, did it come with the little plastic clips or were those separate?
From a resonance and vibration perspective, the fact that the bar is joined to the skin at welds only would obviate applying deadening across skin and bar. That was part of my reasoning.
As for water, the stuff I used claimed to be hydrophobic and given it’s made of this aluminum foil and butyl the claim made sense to me. I didn’t wrap the whole crash bar to prevent trapped water.
Weatherstripping came with clips. I ordered Toyota parts from ebay.
I don’t believe force needed as you’re dealing with vibration. But enough force depending on how thick the mat is so it folds adequately to fit in the crevice. Personally I just folded and jammed it in by hand.
Again, not claiming to have the holy grail but seems to align with the physics and logic behind how pros seem to do it.
- Thread starter
- #6
Yeah that’s what I was trying to figure out, basically wrap the bar or not. Sounds like the consensus is basically not to worry too much about it. Thanks!