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I just noticed this pic of the door panel on the 240sx on Hybrid's website and noticed that some of the sound deadener is applied in little overlapping strips, kind of like overlapping tig weld pattern. Has anyone else done something similar?

 

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not sure there is any advantage to that. seems like alot of work for very little gain.
 

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They probably put on a few medium/large pieces and then used those small strips to fill in all the gaps.
 

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Agree that it is much more difficult to install continuous pieces of dampening material than tiny strips. Looks like a job done by a novice to me. On the high quality professional installs, I have never seen the dampening layed in that manner.

If a professional shop did an install like that im my car, I would not be pleased with the result. While I know that its more a matter of how it works instead of how it looks with mat, it would still bother me.

I dont think Dynamat would use that photo in their marketing materials. :)
Then again, for this forum it is afterall DIY.
 

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That is indeed a very good job. Also, notice there are no speakers in that door, they are in the kicks. It looks like those little strips are extra pieces as well, layed on top of a solid layer underneath. Either way, in this case the panel is deadened to keep it from making any noises, not to support the speakers, since there are none in the doors. BTW, if thats the car I think it is, that is Scott Buwalda's old car.
 

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I have a few installers that install it that way. I don't think you gain much , but it is indeed easier to apply some of the deadeners in that fashion for sure.
 

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Good luck getting at the window track!!!
If that photo is more than a couple of years old I'd bet it doesn't look like that anymore. It's the "no maintenance will ever be required" approach that many of us followed early on.

I'll never need to get inside that door again.
The fuel pump will last forever.
I'll never get a ding in that quarter panel.

:D



Oops.
 

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Obviously not an adherent of Don's 25% coverage theory. :laugh:
Not only that, but he isn't familiar with the theory that the backing material is part of the damping structure, and the ideal backing material would be equal in thickness to the panel to achieve the same resonant characteristics. When you cut up your material like that, I would imagine it destroys any resonant quality at all and makes the backing totally useless.

Dan
 

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Not only that, but he isn't familiar with the theory that the backing material is part of the damping structure, and the ideal backing material would be equal in thickness to the panel to achieve the same resonant characteristics. When you cut up your material like that, I would imagine it destroys any resonant quality at all and makes the backing totally useless.

Dan
If his goal is to reduce road noise and quiet the cabin, he probably succeeded with his install.

For me, that is one major purpose of deadening the doors. I like quiet car interiors regardless of the sound system.

The added improvement to the sound system quality is bonus.
 

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Not only that, but he isn't familiar with the theory that the backing material is part of the damping structure, and the ideal backing material would be equal in thickness to the panel to achieve the same resonant characteristics. When you cut up your material like that, I would imagine it destroys any resonant quality at all and makes the backing totally useless.

Dan
In reality, that backing was never part of the damping system - .5 mil foil.
 

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If his goal is to reduce road noise and quiet the cabin, he probably succeeded with his install.

For me, that is one major purpose of deadening the doors. I like quiet car interiors regardless of the sound system.

The added improvement to the sound system quality is bonus.
It would certainly help for that. Less effective than a decoupled barrier layer with more mass to it.
 

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That "novice" installation was done by me. LOL You guys kill me. Wanna see some of my other "novice" work? Welcome to the Buwalda Hybrids International Website - Home of the Triple Threat!

That photo is about six years old, and looks the same today as when that photo was taken six years ago. Well, there's a little red overspray where the car was re-painted. If a door lock plunger or window motor fails, what's the problem with taking a razor knife and 30 seconds to cut that access hole back open? Having a pseudo-sealed enclosure to abate tactile effect, road noise, and etc. for six years certainly outweighs the incredibly laborious 30-second project of cutting an access hole back open.

And since when do we encourage resonant structures in the door panels? We're not trying to achieve "resonant characteristics." We're trying to achieve an aperiodically arranged mass-loading structure to selectively ELIMINATE resonant structures. With unequally sized and asymetrically placed pieces of damping, the resonant structure is eliminated because of the periodic and aperiodic ordering and varying thicknesses of the damping strips. With one solid sheet of deadening, there might actually be resonant communication there.

No, this was not done to save scraps. And no, this is not easier or less time-consuming than a simle sheet of deadening.

There was one glimmer of hope above...yes, the strips were laid down across the two center points of the door frame where I purposely placed a seam. The thought process was that a resonant structure would be most likely manifested through the center of the door frame, not on the edges where the metal is thicker, rounded, and reinforced.

I would be tickled pink if an installer did this to my car.
 

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My general rule for applying deadener is to cut it up into small, easy-to apply pieces, and then keep adding them until rapping on the sheet metal with my knuckles produces no more "ring". This usually leaves me with about a 75%+ coverage ratio with some small gaps here and there. I think the "25%" thing is a minimum, not an ideal.

That having been said, the OP picture seems a bit overdone. But, hey, its not my car. Lots of stuff I have done has been "overdone". Right now I am modelling the bracing for my new sub box in google sketchup... :)

 

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