47-55.1 sound deadining

[nvrdone]

ok, so any one care to recommend their favorite sound deadening material? im ready to do the floor and back of cab to insulate from sound & heat. any ideas would be appreciated.

[Black_Sheep]

Full coverage inside the cab with FatMat Rattletrap and an extra layer of FatMat floor liner from the top of the firewall to the seat riser. On top of that is some heavy jute padding and carpet. It drastically reduces road noise and heat.

[joedoh]

there are three methods of sound intrusion, direct (air leaks) resonance (panel vibration) and reflected (hard surfaces).

adding an extra layer of deadening material usually isnt needed. asphalt and weighted sound deadening works by lowering resonance. resonance is sympathetic vibration. sound travels better through solids than through air, because of density. you dont "hear" the sound in a sealed cab directly, you hear the sound vibrating the panels of the cab and recreating the sound in the cab. there is a special frequency that takes the least amount of input vibration to create the loudest output sound, that frequency is called the resonant frequency, its usually in the speaking tones (100-4000hz) and that is why road noise is the most annoying, it can cancel out your speech or at least make it very hard to hear what someone is saying.

adding mass to the panel with asphalt or heavy padding lowers the resonant frequency significantly, usually it doesnt even take a complete coverage to half or even quarter the frequency. adding mass beyond that point isnt useless, it does serve to lower the resonant frequency even more, but the costs of extra layers and complexity of installing more make it a diminishing return. meaning if you half or quarter the noise on the first application, a second application may only half again the first half or quarter again the first quarter. lowering the resonant frequency means it will need much more input "power" to make the same amount of noise. ever bought a subwoofer amp? they are huge, because reproducing lower frequencies takes a lot more power than higher frequencies. it is the same with panel vibration. the more mass in the panel, the more power it takes to make it vibrate, the less vibration, the lower the noise.

people will often say " the doors shut more solidly with a THUD", but that is just a description of a heavier door shutting, it has nothing to do with the transmission of sound.

in my trucks I usually tackle the air leaks first, new door seals and window channels, and especially holes in the firewall. that takes care of direct sound intrusion. then I apply foil backed asphalt material to the floor and trans tunnel to dampen resonance, focusing on large flat panels, applying material to corners has no effect. then I apply a heavy jute to the floor under the carpet to take care of reflected sound. I can usually have a quiet conversation in the truck at highway speeds with just that amount of work.

by the way, mass adders are all the same, they add mass. fatmat and dynamat might have better glue, but they are still adhesive asphalt material. I use peel and seal from lowes, its about 16 dollars a roll.

[65blackfleetside]

2nd vote for rattle trap. Its cheaper than some of the other brands and basically the same product. I also used 2 extra layers of carpet insulation. and rattle trapped the inside of doors. Cab is very quite inside.

[nvrdone]

ok, thanks for the info so far. ive got new door & window seals and all the holes are welded or plugged. I did throw some jute rug padding under the carpet and that has helped. just trying to get the best level of quiet I can.

[Iceman_70]

looking into this subject myself for my 56 truck ...
Did some research on the net, and I think I will be going for Noico 80 mil sound deadening mat with a layer of Noico Red 150 mil liner.
It's butyl based like Dynamat, but at 1/3 of the price... saw some good feedback on Noico here on the forum as well.

[mr48chev]

Sound wise, lurking around om some of the car audio boards brings up some good info and methods.

The same material doesn't always do best with sound and heat though.

I have had Fat Mat on my watch list on Ebay for years waiting for when I am ready to buy it. It seems like a pretty good material for the buck.

[Tempest67]

how do you guys 'sound deaden' the doors?

Do you just add material to the inside of the passenger compartment under an interior door panel?

OR

Do you apply some kind of material INSIDE the door cavity?...and if yes, to the outer or the inner door skin?.......... or will this hold moisture and cause rot??

[nvrdone]

I had some old poly styrene (?) board glued inside my doors. its on the out side surface. seems to kill a lot of noise. its been in there for over 40 years and when I pulled it off there was no rust on the door surfaces.

[_Ogre]

Originally Posted by Tempest67

how do you guys 'sound deaden' the doors?

Do you just add material to the inside of the passenger compartment under an interior door panel?

OR

Do you apply some kind of material INSIDE the door cavity?...and if yes, to the outer or the inner door skin?.......... or will this hold moisture and cause rot??

i did both methods. since i have full door panels i was able to cover most of my door with raammat, my door panel probably blocks some noise too. i also cut smaller pieces to go inside the door on the outer skin. you don't need 100% coverage to block noise. anything inside helps

on the floor i have rhino liner bedliner underneath, raammat and ensolite foam. where my heal rests on the carpet while on the go pedal, the foam and raammat has been displaced. i would suggest something else only in this are. even a piece of 6x6x3/16" plywood under the carpet would work. as is i have a big divot under my heal

[1project2many]

I have owned two TF trucks and in their old, beaten condition the noise in the cab was too high for comfort. When I built my '57 I made sure to seal the doors tightly and used undercoat inside the door skins. I sealed the back of the cabs with new cab corners, sealed up all the seams, and used jute liner under the mat as well as on the firewall pad. The truck was sealed so well the doors wouldn't close unless a window was open. The wind and road noise were gone but the windows couldn't be lowered more than about an inch on the highway. The back of the cab would start to flex and create a low frequency vibration that drove me out of the cab! Folks suggested a number of fixes for the vibration but the real issue was lack of proper cab venting. I have no intention of cutting up the cab at this point.

The only other problem is that 20 years have passed and my door seals seem to be shrinking. I can hear more wind noise than when I restored the truck.

[my56chevytruck]

I used a product I found on this truck forum; CARINSULATION. Very good price for our trucks, great people to talk to and easy to install. I did the floor and inside the doors.

[Chris(NJ)]

Originally Posted by Tempest67

how do you guys 'sound deaden' the doors?

Do you just add material to the inside of the passenger compartment under an interior door panel?

OR

Do you apply some kind of material INSIDE the door cavity?...and if yes, to the outer or the inner door skin?.......... or will this hold moisture and cause rot??

If you're looking to kill the rattles and want more coverage than the little access port provides, Second Skin Audio makes a liquid "damplifier". They sell it in a spray or in a sludge.
I've used it before on an old S10. Works great.
I guess it depends how crazy you want to get and what stage youre at w/ the truck (is it on the truck or off). SSA suggests a minimum of 60% coverage with a butyl rubber mat to effectively kill the noise resonance.
If you're looking to do more than just rattles, you'll have to start applying layers of sound blocking and absorbing material to knock out the noise.

Since deadening that s10 years ago, I've stuck with their line of products and have been happy w/ them. I just finished using Damplifier Pro, Luxury Liner Pro, Heat Wave Pro on my Toyota Tacoma and have starting applying the extra to the floor of the 3100. I already did the doors, applying Damplifier pro to the lower sections of our doors. Applying to both the outer and inner skins, as much as I could reach.
For my purposes, thats good enough on this truck. I drive w/ the windows down, so killing road and wind noise isn't a priority on the 3100. Reducing rattles and heat is more important to me here.

Anyway. No affiliation, but I checked the second skin audio site and they're running 20% off for the holiday. I'm sure other manufacturers probably are too, but figured it was worth mentioning because these kinda projects can get pricey. I think I dropped around 700.00 on my Tacoma.

[Chris(NJ)]

Originally Posted by mr48chev

Sound wise, lurking around om some of the car audio boards brings up some good info and methods.

The same material doesn't always do best with sound and heat though.

I have had Fat Mat on my watch list on Ebay for years waiting for when I am ready to buy it. It seems like a pretty good material for the buck.

Yea, usually a Jute Insulation pad for heat, but there'll always be some slight crossover benefits. Heat insulation material will still manage to absorb some noise frequencies, it just won't excel at it.

[72Mountaineer]

I used the Noico 80ml seems to work good. Get yourself a good hard plastic roller. I did my doors with the Noico, takes the oil canning out. Also lets you know if your door hinges are getting weak.

[fisherman420]

Noico for the sound deadining. As others have stated, eliminating road/ wind noise through the doors and firewall are just as crucial to a quiet cab

[MidLifer]

This guy retired a year ago but his site is still up. IMO required reading before you go spend a bunch of money on "mat". I've used his methods on my vehicles with great results.

https://www.sounddeadenershowdown.com/

"Mat" is not sound deadener, it's vibration dampener, and as an earlier poster said, you don't need to slather it all over your metal. 30-40% coverage is enough to achieve the goal of reducing vibrations..

What's more important is actual deadening material, meaning mass loaded vinyl. It's what they use to create soundproof rooms. It's heavy as hell, but actually blocks sound waves from traveling.

If anyone here is in touch with Don, the former owner of that website, please DM me. I've been trying to reach him. All good, I want to give him some money.