Reduce 04 STI Cabin Noise

Discussion in 'Modifications & DIY how-to' started by chuglobal, Jun 22, 2010.

  1. chuglobal

    chuglobal Member

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    I have an 04 STI w/ 120K+ miles. I've noticed over the last 1yr+ that the inside cabin noise has gotten louder ... I'm not sure if it's due to the age of the car, age of the driver ;), etc. I do have aftermarket engine mounts, tranny mounts, sub frame bushings and differential bushings however they've been on the car for way more than one year.

    Are there "things" that I can do to reduce the cabin noise? Can I drop it by a performance shop to install "things" to make it quieter? Will any of these "things" reduce performance? Thanks.
     
  2. Trey

    Trey Active Member

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    Bose Quiet Comfort 3 headphones.....or trade it in on a Lexus. :p
     
  3. Matt

    Matt Think before you post
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    dynamat

    /thread
     
    #3 Matt, Jun 22, 2010
    Last edited: Jun 22, 2010
  4. Weapon

    Weapon 90lbs of dynamite
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    its what makes a Subaru a Subaru
     
  5. Alex

    Alex Community Founder
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    I'll be playing with this over the summer as I work to lessen some of the overall road noise in the car. This is all in an effort to improve SQ inside the vehicle while listening to tunes.
     
  6. Matt

    Matt Think before you post
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    I said /thread!!

    :)
     
  7. Mad Mallard

    Mad Mallard the mad mallard

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    syntax error. ;p

    To answer the original issue, every mount or bushing that's firmer has the potential to increase all noises in the car.

    Increasing rigidity almost always lowers overall dampening. Meaning vibration flows more easily from one object to the next. There are exceptions around certain resonances, but if you run a firmer engine mount, more vibration will travel thru the stronger mount and on into the rest of the car.
     
  8. Matt

    Matt Think before you post
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  9. Matt@Topspeed

    Matt@Topspeed Member

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    Theres a few different things that can be done, dynamat, spray in insulation, and changing the bushings will usually help more than anything.
     
  10. Cool_____

    Cool_____ Banned

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    Go back stock?
     
  11. chuglobal

    chuglobal Member

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    So here's more details ...

    The reason for the whole "exercise" is that 1. We're having a kid 2. I've bought a set of Surefire EP4 (... not the Bose headphone suggestion but close ;)) a month+ ago for some hwy use.

    1. I would prefer to keep the "performance" bushing, mounts, etc so I'm assuming the only option is the Dynamat/Stinger type products.

    2. We actually contemplated picking up a new car for Lynn. We test drove the following cars over the last few weeks in the below order according to faster travel path from our place:

    2009 Accord EX - It's an Accord ... nothing too fancy, Spacey interior, Transmission does not shift cleanly
    2010 Rav4 (4 & 6 Cyl) - Wouldn't touch again
    2011 Sonata SE - Interior/exterior design is much better than previous versions, Low headline especially w/ sunroof, Smaller interior than expected
    2007 GS330 - Most quite, Nice torque to handle heavy body, Most expensive, Smaller interior than expected
    2010 Forrester (4 & XT) - 1st & 2nd Choice
    2010 Legacy (4 & 6 Cyl) - 1st & 2nd Choice
    2010 Fusion (4 & 6 Cyl) - Most "features," Terrible handling (Feels heavy)
    2010 Civic LX - Least Expensive, Best MPG, Least quite, Non-ergro interior
    2010 Outback (4 Cyl) - Quite for a pseudo SUV, Drives/Handles quite well

    We were looking at the following areas: cabin noise, interior space (passenger areas), driving/handling (acceleration/turning), ergonomics, mpg. The Legacy 3.6R and Forrester XT are the top two choices. The Legacy has the 2nd most quite cabin behind the GS330 and has the most interior room, even against the Accord. It also handles quite well. However I'm debating between the 4 w/ CVT for MPG or 6. I did not get a chance to drive the Forrester XT but Lynn seems to like it the best. Ultimately I was suprised at how Subaru dominated the competition ... I guess "It's what makes Subaru and Subaru." :)

    I think we'll try plan A and then go to Plan B as a last resort ... interesting, two Subaru's in the same garage.
     
    #11 chuglobal, Jun 30, 2010
    Last edited: Jun 30, 2010
  12. Cool_____

    Cool_____ Banned

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    Try this stuff Second Skin’s Damplifier… I think it’s more expensive than Raammat… but much cheaper then Dynamat Pro.

    http://www.secondskinaudio.com/

    What makes it good is that it’s a true vibration dampener… not just a mass loader like any of the asphalt-based products.

    It’s now produced in a variety of weights and thicknesses… there’s a Lite version now as well. The stuff is very easy to work with and holds up very well… no issues even with all this heat we have been experiencing.

    It works really well.
     
  13. Matt

    Matt Think before you post
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    after driving a 2010 Forester over the weekend, I was VERY impressed with it. Except since it was the base model, it was turd slow. That thing needs a 3.6 H6 in it, bad....or the turbo. :)

    Oh, and a 6speed :D
     
  14. Alex

    Alex Community Founder
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    Some of the Subaru owners on DIYMA suggest that you remove the carpeted pieces from the trunk and apply an acoustic foam to it rather than actually applying anything to the sheet metal back there. They report good things.
     

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