Sound deadening

[Garrison]

I'm going to be trying some sound deadening this weekend on my wagon. I've been doing some research around on RS25 and NASIOC and both say very similar things about the location of the material, doors, strut towers, shifter surround, flooring, trunk area, etc. I downloaded a DB meter on my droid, which read a constant 72db +/- 2. I am hoping to cut down on road noise, as well as improve the "feel" of the doors.

I'll be using 3/8" (10mm) thick yoga mat (closed cell foam, CCF), which is very similar to ensolite, which has nothing but positive reviews all over. I've got about 34ft^2 which should do both front doors, shifter surround, and shock towers. Dunno how much I'll have left over, if any.
https://sl-i.net/FORUM/images/imported/2012/02/505020376_ojpgnc80-1.jpg

http://www.ebay.com/itm/250917667044?ss ... 577wt_1139 (http://www.ebay.com/itm/250917667044?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1497.l2649#ht_2577wt_1139)


I'll be following the basic guidelines from these two threads:

http://www.rs25.com/forums/f105/t169712 ... jects.html (http://www.rs25.com/forums/f105/t169712-d-i-y-inexpensive-light-weight-noise-reduction-projects.html)

http://forums.nasioc.com/forums/showthr ... ?t=1076510 (http://forums.nasioc.com/forums/showthread.php?t=1076510)


Just wanted to let you guys know about the project, just in case you had some helpful advice or tips to avoid headache.

Thanks :smt023

[mlitz]

Closed cell foam is great for High frequency noise but if there is any type of rattle it might not help that much... using a materal like dyno mat or hush mat will be a better bet... and using them both will be best of both worlds.

[bulldozer24]

I used a product called frostking, it is a duct insulation. It is a self adhesive foam with a foil backing. it greatly reduced road noise and made the car feel so much more solid. I put it on all the doors and covered the floor and trunk. Its about 11 bucks a roll at lowes, takes about three rolls (for a sedan).

[Wiscon_Mark]

I used a product called frostking, it is a duct insulation. It is a self adhesive foam with a foil backing. it greatly reduced road noise and made the car feel so much more solid. I put it on all the doors and covered the floor and trunk. Its about 11 bucks a roll at lowes, takes about three rolls (for a sedan).

Interesting, I'll have to check that out.

If you prefer to go with the more purpose built stuff, the online reviews suggest that http://www.raamaudio.com is the place to go. Their website isn't the best, but the tests on their products for effectiveness and durability showed they were the most balanced product, and cheaper than Dynamat Extreme.

[Huffer]

You'll want to use something that is self adhesive and has a foil backing. Noise is sound waves and vibration, so you dampen the metal that is vibrating, and that kills the noise. That's the basics anyway.

[Garrison]

You'll want to use something that is self adhesive and has a foil backing. Noise is sound waves and vibration, so you dampen the metal that is vibrating, and that kills the noise. That's the basics anyway.

So this would be cool?

I used frostking. It is a self adhesive foam with a foil backing.

[bulldozer24]

just make sure your panels are super clean before you apply any product, I used mineral spirits. Also I have had this stuff on for nearly a year, so its been in the hot and cold, and its still stuck.

[Huffer]

^^ Frostking would work. Basically, anything that is adhesive, has a foil backing and has SOME kind of foam or high density layering will reduce sound escaping and entering the vehicle.

Here's the thing to understand about sound deadening a car - the more glass and metal and seams and joins you have, the more difficult it is to eliminate noise.
And it's not necessarily about blocking noise from exiting the car, as it is from blocking noise from coming IN. This is why manufacturers coat the underside and and the floorpan interior with sound deadening. They are actually adding a vibration damper, not a noise block. Dampers take noise vibrations (kinetic energy), and transform them into heat. They absorb the vibration. Similar to how music sounds when you put your hand on the speaker cone, that's what the factory spray on deadener does to your car's floor pan. But it's heavy stuff and when you combine the soft foam and fabrics of an interior, there isn't any need to spray more on the doors and roof skin.

So, here's what adhesive noise deadener (like Dynamat Xtreme) does:
1. It stops the metal panel from vibrating by absorbing the vibration via it's adhesive side
2. It reflects sound waves coming from the other side via it's foil backing.

That's about it.

The other way you can prevent noise transference is to fill voids in the car with a high density foam - but you have to completely fill a cavity (like a tooth cavity) for it to work 100%. A classic example is taking the empty areas in the trunk, and spraying space-filler foam. Keep in mind if you have any electrical or other lines in there, getting access to them is extremely difficult once the spray foam has covered/expanded.

My personal preference for sound deadening in a vehicle is to apply the adhesive deadner/damper to the interior of the EXTERIOR door panel. This requires getting in behind the guts of the door and going in as far as humanly possible. It's not easy. When that's done, I do the same thing to the metal facing the interior of the car (when the door is closed). If you're really serious, you could add more material to the back of the door cards.

Then, my next angle is to do the firewall - either the inside of the cabin or in the engine bay. The cabin side is harder, but the results are better and the deadner doesn't get dirty.

After that, you start laying material behind the plastic cabin trim over the rear wheel wells, into the hatch or trunk area. If you're really serious, you lay another layer over the factory damping in the floorpan, under the seats etc. Then you start on the roof, and the pillars.

When you reinstall the plastics and interior, any of the plastic rivets or pins that hold the interior would get replaced if they are loose and cause the panel to move around.
If you have a sedan, installing a deadened trunk wall that physically separates the trunk from the cabin will help seal out noise, and it means you won't have to deaden the trunk.

As you can see, you could spend THOUSANDS of dollars and time (with the right materials) to get it "right". At the most, you'd be adding a full 150-200lbs of weight to the car. So basically a dead body. :)

[Garrison]

Hahaha, yeah I'm definitely not going to be spending $1000's on this project but a big thanks for the advice.
I picked up this, this morning. They didn't have any $11 rolls, only $4 and $20. So I went with the $20 roll. Between the two, I should be golden right?

https://sl-i.net/FORUM/images/imported/2012/02/IMAG0394-1.jpg






More updates: I turned the Db meter on again whilst driving around today. I saw as low as 62db when at stop-lights, and as high as 76db when accelerating w/ windshield wipers on. Db meter calculated an average of 72db, so I'm aiming to lower that to a more civil 68db or lower if possible.

[Huffer]

Just by insulating the exterior door skin like I suggested above will reduce your noise rating considerably. Bonus will be that your speakers will sound much clearer and have more punch. I've never required a subwoofer in my car when I used speakers that had a frequency response range down to 25Hz.

[Garrison]

My top 3 places are front doors, rear strut towers, and shifter surround.
Following that, firewall, floormats (I heard it makes an incredible difference), and then rear hatch.

If I can hit all of those spots, I'll be happy. Also, any wagon-specifics you can think of?

[Huffer]

Wagons are tough - there is so much more glass and empty space in there. My best recommendation is the under the rear seats, rear strut towers, top of the strut towers, spare wheel area.

[bulldozer24]

Hahaha, yeah I'm definitely not going to be spending $1000's on this project but a big thanks for the advice.
I picked up this, this morning. They didn't have any $11 rolls, only $4 and $20. So I went with the $20 roll. Between the two, I should be golden right?

I may have been wrong about 11 bucks, but that was about a year ago, anyways im lucky to remember to put pants on in the morning :grin:

what do you mean by between the two? did you get both kinds?

[Garrison]

Hahaha, yeah I'm definitely not going to be spending $1000's on this project but a big thanks for the advice.
I picked up this, this morning. They didn't have any $11 rolls, only $4 and $20. So I went with the $20 roll. Between the two, I should be golden right?

I may have been wrong about 11 bucks, but that was about a year ago, anyways im lucky to remember to put pants on in the morning :grin:

what do you mean by between the two? did you get both kinds?

No sir, I meant a combination of the yoga mat, CCF foam; and the frost king roll. Though now that I think about it, 2 rolls may have been a better idea :/

[Huffer]

Be careful with that much thickness of foam etc. You're going to have issues with bolt lengths if you install this stuff under/behind anything that has be bolted back down.

Ideally you want a one piece solution; multiple layers means revisiting the area to glue etc. This is why I like Dynamat Xtreme - or similar products. Ease of installation.

[Garrison]

Be careful with that much thickness of foam etc. You're going to have issues with bolt lengths if you install this stuff under/behind anything that has be bolted back down.

Ideally you want a one piece solution; multiple layers means revisiting the area to glue etc. This is why I like Dynamat Xtreme - or similar products. Ease of installation.

So, in lieu of lining the interior (closest to the passengers) of the door with CCF, what about lining each door card to absorb the vibrations instead?

Thanks for all the help, Huff. I wanted to ask these questions, but well... you know how inaccessible NASIOC can be.

[Huffer]

Lining the doorcard is a good idea. You just have to be careful with the push rivets and screws on the doorcard because they're very short.
Making sure your door wiring isn't flopping around too is also a good way of stopping any weird buzzing sounds.

No worries about the help - I think many moons ago I gave similar advice to Grafton in this same subsection. The advice hasn't changed because sound waves still travel in the same manner. :)

[Garrison]

Update:

Project is completed! For now. I lined the inside of both front doors with wrap, did the doorcards with CCF mat, did the shifter trim with CCF mat, and did the trunk area, strut towers, and trunk hatch; all with frostking mat. It was almost 8 hours of work with my buddy Greg. But it all turned out well. I'll let him give his impressions.

Greg:

Hello all,

I just wanted to point out a few things to watch out for. I suppose the first to mention would be something that I believe is just good habit to have.
-Hold on to your nuts! trust me, you don't want to lose these sons-of-bitches. Nuts and bolts are easy to lose and keeping track of them just helps.
-Keep track of your holes clearly marked. It's easy to lose the hole when you put down the insulation and foam.
-Speaking of insulation; after you have laid down the frost king insulation in the rear of the car, replace the side carpeted-paneling before you lay down the insulation on the spar tire flooring.
-With the first door, lay the insulation in strips and get an idea of how you would apply it for the other door. The practice helps, the second time around went much smoother/quicker.



My impressions:
Now that I've been able to drive the car for a little while, I can comment that audio quality has jumped dramatically. Before 15-20 was adequate, now 3-8 is adequate :grin:
As far as noise reduction, the db-meter shows only moderate drop (61db idle, 71db +/- 1 driving); scientifically a failure, but in terms of tactile feel; it is a marked improvement. The car feels SO much more solid now. You barely have to whisper to be heard in the cabin, where before you had to speak to be heard.
Finally, the shifter feels crisper and better contained.

We also swapped back to OEM headers. I missed my mid-range :D

https://sl-i.net/FORUM/images/imported/2012/02/DSC_4031-1.jpg
https://sl-i.net/FORUM/images/imported/2012/02/DSC_4028Copy-1.jpg
https://sl-i.net/FORUM/images/imported/2012/02/DSC_4035-1.jpg
https://sl-i.net/FORUM/images/imported/2012/02/DSC_4042-1.jpg
https://sl-i.net/FORUM/images/imported/2012/02/DSC_4043-1.jpg
https://sl-i.net/FORUM/images/imported/2012/02/DSC_4047-1.jpg
https://sl-i.net/FORUM/images/imported/2012/02/DSC_4053-1.jpg

[Wiscon_Mark]

An improvement is an improvement - Are you thinking of attacking the firewall at all? I have a lot of engine noise intrusion and was pondering how to go about that.

[Garrison]

Mark,

I really want to, but I am not going to tear out the dash. Period. So, that leaves the engine side, which I think would need a layer of something over it in order to keep it clean/undisturbed. But, as Reason said, it is 1000x easier that tearing out the dash. I really can't imagine that it's worth that. The floorboard/under-carpet in the front however, absolutely. Adding a layer underneath the front carpet would be a grand idea.

I think I'm going to do the skins of the rear doors, and the carpet/floor/engine firewall next time I do this and I'll take more measurements to see if there is any actual improvement.
Now that I've lived with it for a bit, I'll say this. The front doors close more "solidly" than before, though I now hear strange rattles and squeaks every now and again. Nothing terribly irritating, but still apparent.

[Wiscon_Mark]

FWIW, the vertical part of the firewall does have some insulation, unlike underneath the carpets on the floor. The the floor panels would be the best place to start.

[Garrison]

FWIW, the vertical part of the firewall does have some insulation, unlike underneath the carpets on the floor. The the floor panels would be the best place to start.

All the more reason to do them. That's what my next afternoon of play will be. Engine-side firewall, floorboards, and rear doors.

[Wiscon_Mark]

I went to Lowes today and bought a roll of it and started myself. I can't wait to get more done and see the results!

[Huffer]

The dB scale isn't linear. So a drop in 2dB isn't like say a change in height from 5ft to 4'10".

What you have done is actually begun to muffle and suppress sound waves from outside the cabin area. The reason your music sounds better is because your speakers are not having to combat the vibration of the door metal to produce their sound. You are actually beginning to hear what those speakers would do in the lab environment that they were constructed in.

Good job.

[Wiscon_Mark]

Here are some pictures from my work in the rear:
https://sl-i.net/FORUM/images/imported/2012/03/20120301161222-1.jpg

I might throw some of the leftovers (if I have any) in the missing spots in the spare tire well when I'm done with the tailgate & doors.

Also you can see my fender rust from the inside, ewwww:

https://sl-i.net/FORUM/images/imported/2012/03/20120301161231-1.jpg

[Wiscon_Mark]

After doing my wheel bearing job in the rear, I notice a HUGE difference in noise level. I did:

- Doors, inside & outside panels
- Under the rear bench seat
- Around the strut towers, and inside & outside panels
- Every square inch of the trunk bottom, including the spare tire well
- The hatch, inside & outside panels

The only thing I really didn't do, was underneath the carpeting in the front & rear seating areas, and the firewall - both which require a lot more work.

The Frostking stuff probably isn't as good as Raamat or Dynamat, but it's a little less expensive and doesn't require me to ship anything. It was very easy to cut with a blade, and stuck well. It certainly shouldn't have any temp issues as it's made for heater ductwork. Overall, good stuff. I spent almost 100 bucks to get the coverage on the areas I listed above.