Sound Deadening Pattern?

[Zonaman]

I've been told that sound deadening does not need to be applied wall to wall in the truck cab to be effective. That a certain pattern of patches applied in strategic locations will work. Can anyone verify this or (better still) post up the correct pattern if so?

Thanks

[cj847]

I am not sure I am right but I put sound deadener on unbraced sheet metal. Also, you can tap areas with your fist or something.

For example, there is no need for sound deadener on the cab floor directly above the floor supports or along the seam where the firewall and floor meet. But it is needed anywhere basically 2-3" from such a structure. Basically, anywhere two pieces are welded together or there is a formation in a flat sheet of metal there is no need within 2-4"

Another example the back of the cab - you can just put a chunk of deadener maybe 2"x 8" in each of the "vallys" and "hills".

The outer door skin needs a piece about 8" x 8" or whatever you can fit. The inner door has enough form, it doesn't need anything.

[ItWillBeSlow]

I installed mine similar to the advice above. I only had one box and it is obvious it won’t ad value at weld seams and structured supports. It is not a science and doesn’t need to be perfect or cover every panel completely.

[LockDoc]

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I would think if you were using a product that was also considered a thermal barrier it would have to cover the entire surface. At least from the front of the seat forward to the firewall insulation.

LockDoc

[ItWillBeSlow]

Originally Posted by LockDoc

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I would think if you were using a product that was also considered a thermal barrier it would have to cover the entire surface. At least from the front of the seat forward to the firewall insulation.

LockDoc

I agree with this. You can go over everything with an insulation as well. I covered the whole pan and footboard with insulation on top of the deadening.

I used Noico products and they seemed pretty decent for the price.

[SRU1436]

This is what I did. As for if it really helps, I’m not sure.

[Rich72C10]

flip

More has to be better in this case, especially if it is also a heat barrier. It also looks cooler LOL

[SRU1436]

Originally Posted by Rich72C10

flip

More has to be better in this case, especially if it is also a heat barrier. It also looks cooler LOL

Thanks for the flip. I believe mine is a sound barrier and heat barrier.

I used Noico 80 mil (2 mm). I still have a bunch left so I’m going to use it on my chevelle.

[Dieselwrencher]

Originally Posted by Rich72C10

flip

More has to be better in this case, especially if it is also a heat barrier. It also looks cooler LOL

Which brand did you use?


I also agree I would just cover the entire area. You are already there so why not do it all? If you spray sound deadening on, you just don't to the non backed areas IMO.

[BASE]

Originally Posted by ItWillBeSlow

I agree with this. You can go over everything with an insulation as well. I covered the whole pan and footboard with insulation on top of the deadening.

I used Noico products and they seemed pretty decent for the price.

That's the general approach used by our acoustics guys on the aircraft I have worked on. Lead impregnated polymer stuff in the frame bays, then thermal insulation on top of it all. I'm a structures guy but I think the theory was that it damps out the lower frequencies that the panels would resonate at. The thermal insulation probably helps with the higher frequency stuff. I do know it worked well, the aircraft were dead quiet after the treatment.

[Peanut74]

X2 If it is sound dealer and thermal cover all the floor. Also, the toe board, back of the cab and the I side of the door.

[Pekoe1111]

Originally Posted by Peanut74

X2 If it is sound dealer and thermal cover all the floor. Also, the toe board, back of the cab and the I side of the door.

The opening on the inside of the door is pretty small. Any tricks to putting the deadening panels like Dynamat or Kilmat inside the doors? I would imagine small pieces at a time, window in the up position.

Thanks

[Zonaman]

Thanks for all your help, much appreciated!