Topic: How-To: Sound deadening

[Elias]

I had this description in my build thread but it didn't seem to be the right place for it, so here it is, my first DIY post.  This job is ridiculously easy but time consuming

After the interior panel(s) are out, you'll need a heat gun, roller, knife (with a lot of spare blades) and I like to use a scraper on the edges of the mat:



Pay attention to the components that need to be reinstalled (door clips, etc) and cut them out so everything sits nice and flush once you reassemble.  Note in this picture the backing is still on the butyl/foil mat, you want to make any small cuts or provisions for harnesses before exposing the sticky backing:



Heat up the metal of the door and the mat with your heat gun, the more the merrier.  You want to use the largest possible sizes of mats with the least amount of cuts as you can, this will make your life easy.  If you make long cuts to allow for wiring harnesses to pass through, apply the top of the door prior to exposing the backing for the bottom.  Some of the other products I've used in the past would become too brittle to allow for this:



If you end up with a seam on an opening:



Take a scrap and create a "stitch" by applying it to the sticky side of the mat:



Before:



After:

[Elias]

Floor install, way easier, minimal trimming

Here are the sheets laid out:



Install (don't remote factory deadening!)



Back together:

[Zaider]

Looks good. Something I wish I'd done when my car was apart. I've got the trunk and a couple of the doors all done but I was too lazy to remove the carpeting.

[Elias]

Thanks Zev.  It's really worthwhile to cut down on the road noise and help acoustic response, not to mention the thermal barrier!  I was actually pretty surprised the night I did the floors and finished the front doors I closed the car up, the garage was nice and warm plus the heatgun and heat retention of the mats heated up the interior.....I shut the car and didn't open the garage for a few days....after it got down to -10 outside.  Garage was cold, interior of the car was still warm  .  I'm thinking it'll stay cooler in summer and warmer in winter when its parked outside and more amenable when racing through the desert (more on that in another post)

Back to sound deadening...

Front doors, cover the outside skin as best you can (this wasn't conducive to pictures) and finish the inside skin like the rears.  I opted for a bit less coverage up top on the inner door skin vs. the rears just in case I ever had to replace window parts:



If you're going this far, add acoustic baffles or extra sound deadening directly behind any speakers:



There's roughly 12 sq ft of deadener in each front door

Front tires and fenderwells are notorious in our cars for transmitting noise inside the cabin, so I triple coated the tops of the fender liners in sprayliner:



I'll finish the front fenders with sound deadening on the inside of the metal, they are paper thin!

[Elias]

reserved for pics

[Jay89]

So what material did you use and where you get it? Is it heavy?

Sent from my LT30a using Tapatalk 2

[Elias]

I'm using a product called Damplifier Pro from Second Skin Audio http://store.secondskinaudio.com/.  It is hands down the easiest CLD product to work with that I've ever used.  I've installed Dynamat Xtreme, Brown Bread, and Roadkill and the Damplifier is significantly thicker, and has an additional butyl layer on top of the foil which makes it superb for stretching and conforming to curves and angles.

All sound deadener is heavy, there's no way to really get around this, but for the minimal weight addition, I feel the benefits greatly outweigh the negatives.  Damplifier Pro is .6 lbs per square foot and I ordered a 100 sq ft pack directly from the manufacturer in Tuscon.  The cost, even with shipping, brokerage and duty was way less per square foot than buying a competitive CLD product north of the border.  I doubt I'll use all 100 sq feet even once the trunk area and the roof are finished as our cars are pretty small.  The weight addition should be roughly 50 lbs total for all deadener. 

[jvd]

I'd like to add that you don't need 100% coverage with a CLD. The manufactures usually recommend about 25%. It is also most effective towards the centre of large flat spots. Most curved areas won't need any. Knock on the specific areas and you'll see what I mean. Nothing wrong with applying more however.

Also, a CLD prevents panels from resonating. If you want to BLOCK sound from entering cabin of the vehicle you need a barrier material like mass loaded vinyl(MLV).

The most appreciable difference I've noticed with these cars is adding CLD on the inside of the outer door skin. Sealing up the holes in the inner door skin will also greatly improve midbass from your speakers. MLV if you really want to quiet down the interior.

Thanks for sharing!

[HowFast]

how long did all this take, like you've gutted the interior of the car lol, for a guy like myself (considerably lazy on a weekend) what am I getting into to do a significant job?

[flipincanadian]

Nice write up.  I followed a similar tutorial on subaruforester.org to get me started.  I used B-quiet extreme in the rear hatch area. I still need to order some B-quiet v-comp to go in the door skins. 

[krisr33]

How much of a difference does this make for highway driving? I just did a 10h drive to vernon, and felt like my ears were going to bleed.

[funk32]

it will do a lot, the earlier cars did not have much sound deadening. and by earlier I mean 02+... My STi had none attached to the floor or doors just the carpet lol

[Fry]

Can you throw up a video of how it sounds inside the cab now? and if you have a before video that would be sweet.

[funk32]

I don't have anything done, but I'm sure other members could help out.

[KennyB]

I did my floor and front doors, rear parcel shelf, and some spread around in door panels quarters, roof etc and it's done quite a bit to cut down exhaust noise, road noise, wind noise, maintain cabin temprature as well as make my stereo sound better. I did it fairly sparingly and strategically to avoid adding too much weight, I see how BMW's and other manufacturers place it from tearing them apart all day and it's not hard to see why Subarus are so much louder, thinner metal and no noise deadening make it like sitting inside a vibrating tin can compared to something German. I don't have a video any before and after video though and an after video isn't going to do much good without a before video to reference. My car is still loud, between the exhaust, intake, and all the suspension/drivetrain bushings and mounts there is all kinds of noises and buzzes but are all much more muted than before and not as overwhelming when they all combine.

[AdamMc]

I wonder if there is some kind of spray on material that could achieve some of this effect but in an easier way.    Masking a few things and then spraying the inside of a door would be pretty handy.

[Unholysavage]

there are tons of spray-on/paint-on sound deadeners on the market. google is your friend.
I've never been a fan. they're messy, and needing to tape things off eliminates time savings.

sound deadening mat/tile isn't hard at all to install. and like JVD said, one doesn't need full coverage with good deadeners like CLD tiles etc, making the job even easier.

[otakusan]

Very good write up, I think I'll order some and line at least the trunk to reduce some of that exhaust noise.

Thanks