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The Sub kit guy
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Discussion Starter #1 (Edited)
One complaint many people have about the Forester is how loud it is. I'm going to see what can be done about that.

My XT is currently torn apart as I've been busy making sub kits and designing parts. Now it is time to put my car back together and I want to make it quieter while I'm at it! I'm going to document what I do and what the results are.

I'll be using the following to quiet the car:
RAAMmat
Ensolite
polyfiberfil (pillow stuffing)
expanding spray foam

Everything I do will be with commonly found items available to everyone, and I want to keep the costs to a minimum too. Nothign exotic or fancy will be done or used.

To document everything I have a Radio shack digital SPL meter. I will be using the same roads, same speeds, and same SPL meter placement to record the sound levels. It will be recorded "A" weighted with a slow response to eliminate the highs and lows and get more of an average.

Current condition:
Rear hatch interior stripped, nothing extra added yet-
Idle: 62 db
30mph: 72 db
60mph: 76 db
1st gear WOT to redline: 72 db
2nd gear WOT to redline: 76 db

Compared to RAAMmatted X:
Idle: 53 db
30mph:
60mph:

I will update and things progress...
 

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The Sub kit guy
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13,100 Posts
Discussion Starter #2 (Edited)
The results:

Begining:
Idle: 62 db
30mph: 72 db
60 mph: 76 db

Notes:
The car is LOUD. Exhaust and road noise dominate the cabin when driving.

Completed driver side of hatch:

Idle: 61 db (-1 db overall)
30mph: 71 db (-1 db overall)
60 mph: 75 db (-1 db overall)

Notes:
The car is still loud, but it is mainly road noise I hear. The exhaust noise is greatly reduced.

Completed Rear hatch door:
Idle: 59 db (-3 db overall)
30mph: 71 db (-1 db overall)
60mph: 75 db (-1 db overall)

Notes:
At idle the exhaust was cut down even more, and all I can hear is the engine. Even though the 30/60 dbs remain unchanged, the sound of the road is different. Not as annoying as before.

Completed passenger side of the hatch:
Idle: 58 db (-4 db overall)
30mph: 69 db (-2 db overall)
60mph: 74 db (-2 db overall)

Notes:
Even with the foam floor still out, the car is MUCH quieter. The road noise from the rear is nearly non-existant, and now I notice more rattles and noise coming from the doors that I di not notice before. The noise from the hatch no longer drowns them out.

Completed the floor install and I added a Whiteline rear strut bar. Basically the entire hatch is back together and looking stock:
Idle: 54 db (-8 db overall)
30mph: 68 db (-3 db overall)
60mph: 73 db (-3 db overall)

Notes:
the car feels tighter, closing the hatch gives a more solid thud, and there is no noticable noise coming from the back now. The road noise thru the doors and the window wind noise is now much more apparant. Now on to what should make the biggest difference...THE DOORS!

The front doors have been RAAMmatted and covered in ensolite. Here are the new results

Idle: 54 db (-8 db overall) ~ 55 db (with new exhaust and snow tires)
30mph: 65 db (-6 db overall) ~ 68 db (with new exhaust and snow tires)
60 mph: 70 db (-6 db overall) ~ 73 db (with new exhaust and snow tires)

Notes:

The road noise has been greatly reduced, and now I notice the wind noise alot more now. Overall I'm very happy with the results and I expect another 1-2 db decrease when I finish the rear doors.

The rear doors have been RAAMmatted and covered in ensolite. Here are the new results

Idle: 55 db (-8 db overall)
30mph: 67 db (-7 db overall)
60mph: 72 db (-7 db overall)

Notes:

I took new baseline measurements before I did the rear doors so I could still get an accurate evaulation of doing the rear doors.

The addition of RAAMmat and ensolite to the rear doors netted about a 1 db drop at both 30mph and 60mph. This does not sound like much and did not show up as much on the SPL meter, but to the human ear it was a very nice difference in road noise tone. There is less low octave resonance (drone) and a much mellower note to the noise. In addition the midbass response from the door speakers was greatly increased (I did add new speakers), so much so that I had to adjust some settings. That's a good thing. The last few rattles I had have dissapeared, and the rear doors now close with a very nice "thud".

Labor time for this was about 2 hours, and that includes making spacers and installing new speakers. Pix will be added shortly to post #3.
 

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The Sub kit guy
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13,100 Posts
Discussion Starter #3 (Edited)
Hatch area:

Sides of hatch (more pix to come)



The trim panel comes with a very minimal deadening and foam trim, so I decided to add a bit myself...

before-



After- I added squares of RAAMmat to the open spaces, and I trimmed the entire panel in foam gasket material.






On both sides of the hatch I completely packed the fenders with polyfil. If I was not adding sub kits to both sides I would have put down a layer of RAAMmat, stuff the entire area with polyfil, then reinstalled the OEM pockets. I also isolated the "vent" with a piece of closed cell foam (blue stuff). I didn't completely block the vent off, but I did make it more difficult for noise to enter the cabin.





Hatch door:

The rear hatch is a big hollow shell, and it is covered in a big hollow trim piece.



All the openings you see in the first pic were completely stuffed with polyfill, and then RAAMmat was placed over it all. I didn't completely cover the hatch door, but I did seal up nearly every opening. I also placed some pipe insulating foam around the lock area to keep the polyfill from jamming it up.



The hollow hatch trim piece was cover in RAAMmat, then I spray glued a 1/2" thick closed cell foam over that. The foam (blue) is from an old sleeping mat I used when camping.


► Edit - moderator's note - the images on this post are not recoverable. :frown:

Bobby...
 

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The Sub kit guy
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13,100 Posts
Discussion Starter #4 (Edited)
How I did the doors:

1) here is the stock door. There is zero sound deadening and it is a hollow open shell behind the door panel. This is why our cars are so loud!



2) I started off my covering as much of the outer door skin as I could reach.



3) Next I marked the door panel mounting holes with a sharpie, then I cover EVERY other hole I could find with RAAMmat on both side, then I completely matted the entire door.



4) Next I ran new wires for my speakers and crossover, then I covered the entire door in ensolite. Since I was putting a 7" mid in the stock location, I made a set of custom spacers to accommodate them.



Rear door with plastic removed. Look how hollow the door is. It's like a big empty tin can.



I RAAMmatted the inside and outside of the door and sealed up nearly every hole.



Ensolite and one of my spacers (baffles) was added to give the new speaker an airtight seal. The sheet metal is shaped so odd it is nearly impossible to get a good fit without it.


► Edit - moderator's note - the images on this post are not recoverable. :frown:

Bobby...
 

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The Sub kit guy
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13,100 Posts
Discussion Starter #10
Cant wait for the results. Ive been contemplating stocking up on RAAMAT for a while now. Wheres a good place to buy it from?
There is only one place to get it...

Contact Rick @ www.raamaudio.com. tell him your a member here and recieve a discount!
 

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I know that deadening the doors alone made a noticeable difference in how quiet the car rode. Then I did the rear hatch area a ton and then stuffed polyfill into every nook and cranny I could find, including all around the spare tire. That also made a huge difference. It's always the sum of the parts when doing deadening. Don't forget to put a layer of foam on the doors and floor!

-Steve
 

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The Sub kit guy
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Discussion Starter #13
My X has all 5 doors, the kickpanels and both rear fenders done. I'll get some measurements of it soon as a comparison. The X is pretty quiet, but my goal is to get the XT even quieter.
 

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My X has all 5 doors, the kickpanels and both rear fenders done. I'll get some measurements of it soon as a comparison. The X is pretty quiet, but my goal is to get the XT even quieter.
i installed a ton of sound deadening myself, it is in my opinion one of the nicest mods you can do. it makes the car a nicer place to be. I've put dyna mat everywhere you have, and the hood. I recommend doing the same, thats where all the real loud noise comes from...
 

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I'll be keeping an eye on this as well. I'm hoping to do my cargo area and rear hatch in the next week or two.

Starting with the back to cut down on exhaust noise in the cabin (more for passengers than for me).
 

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The Sub kit guy
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Discussion Starter #19
I'll be doing the rear fenders and the hatch door first since it is already torn apart. I've already stuffed a huge bag of polyfil and RAAMmatted the driver side fender (inside and out) and I can already notice a difference. When I get the driverside upholstry and panels back together I'll take more measurements.
 
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