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randywebb Samba Member
Joined: February 15, 2005 Posts: 3815 Location: Greater Metropolitan Nimrod, Orygun
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Posted: Sun Jun 19, 2011 10:11 am Post subject: |
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re "create a sealed enclosure for the speaker"
My concerns about that are that enclosure one creates is unlikely to be the correct size for either an acoustic suspension design or a ported one (Thiel alignment IIRC).
Cascade also said that car speakers were usually designed to work into free space. I don't know if that is true or not, but if so, then there seems to be no reason for enclosing the door space (tho the interior panel will necessarily enclose it somewhat). _________________ 1986 2.1L Westy 2wd Auto Trans. |
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Second Skin Rep Jon Samba Member
Joined: June 09, 2011 Posts: 11 Location: Nampa, Idaho
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Posted: Sun Jun 19, 2011 10:19 am Post subject: |
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Yes most speaker makers design their products that favor IB (infinite baffle) or free air mounting. Even if sealed the air space is too large for the cavity to act as a suitable enclosure for the speaker (unless you are running multiple speakers or a fairly large mid range driver).
However not once have I heard a door panel that wasn't sealed sound good as one that was sealed.
If you can, try it both ways and see which has better speaker output. |
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randywebb Samba Member
Joined: February 15, 2005 Posts: 3815 Location: Greater Metropolitan Nimrod, Orygun
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Posted: Sun Jun 19, 2011 11:27 am Post subject: |
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Thanks. _________________ 1986 2.1L Westy 2wd Auto Trans. |
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Second Skin Rep Jon Samba Member
Joined: June 09, 2011 Posts: 11 Location: Nampa, Idaho
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Posted: Mon Jun 20, 2011 9:26 am Post subject: |
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No problem, always glad to give people my 2¢s. |
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tclark Samba Member
Joined: November 21, 2005 Posts: 926
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Second Skin Rep Jon Samba Member
Joined: June 09, 2011 Posts: 11 Location: Nampa, Idaho
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Posted: Thu Jun 23, 2011 4:33 pm Post subject: |
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I'm not entirely sure what compounds are used in all of those different products, but chances are there probably isn't much of a difference. Or at least not enough to tell or have an audible difference.
I've used three of those products (LizardSkin, Noxudol, and SS Spectrum) and all have lived up to their claims and have performed awesomely.
Personally I like the look of Noxudol for areas that aren't covered up. The white just looks better than the gray/black that most of the others have.
So I would say go with whichever product you can get for the best price and like the looks of (if the area you are applying it to is going to be seen). |
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tclark Samba Member
Joined: November 21, 2005 Posts: 926
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Posted: Fri Jun 24, 2011 12:38 am Post subject: |
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OK well I was wondering if there were different formulations in the industry other than the elasto-polymer based products
due to the drastic price point between
http://www.soundtechco.com/damping/vibration-damping-compound/
and the rest see the per gal cost above _________________ 89 Westy with TDI AHU 1.9 manual lots of mods
85 GL 1.9, auto (for sold) |
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Second Skin Rep Jon Samba Member
Joined: June 09, 2011 Posts: 11 Location: Nampa, Idaho
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Posted: Fri Jun 24, 2011 9:01 am Post subject: |
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There are different formulations.
Most significant differences would be the ones that are thermal blocking products. These typically have ceramics or glass beads added instead to them. This increases their ability to withstand higher temps, absorb, block and dissipate the heat, but reduces their ability to control vibrations.
Depending on your goal if you want to block more heat, use the thermal based product. If you want to control the vibrations, use the other product. |
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Classicvibe Samba Member
Joined: August 03, 2009 Posts: 743 Location: Salt Lake City
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Posted: Fri Jun 24, 2011 11:08 am Post subject: |
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tclark, what is your timeline for this job?
I am doing a write-up on the second skin product, with testing before and after. I think I still have a couple of weeks until it is finished, but the resulting data should be very good as a basis to judge this and other products.
We are testing panels individually, and the car as a whole, at different frequencies and decibels. Removing interior and doing it right (I hope). _________________ On a mission, the destination is just an excuse.
Syncro Solstice 2022...see you there!
1986.5 Wolfsburg Syncro Westfalia Poptop Weekender Transporter |
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Second Skin Rep Jon Samba Member
Joined: June 09, 2011 Posts: 11 Location: Nampa, Idaho
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Posted: Fri Jun 24, 2011 2:47 pm Post subject: |
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Johnny, keep me posted too. I'd love to see what the results are! |
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tclark Samba Member
Joined: November 21, 2005 Posts: 926
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Sir Sam Samba Member
Joined: July 19, 2009 Posts: 1690 Location: Fort Collins Colorado!
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Posted: Mon Jul 09, 2012 4:00 pm Post subject: |
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Well I'm back for more, got the front carpet out for carpet replacement and sound deadening, once again I am using the quiet car product all around on the front, currently tackling the inside front, later I think the underside will get some coating.
I took a before video tapping around with a hammer, after all is sprayed and done I will tap around before putting the carpet back in.
I wish I had done a road drive with the decibel meter on the iphone to see if I could record any difference in level of noise.
Some pics:
_________________ '91 Carat Westy
87' Syncro + '87 Westy conversion coming soon |
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BetaVan Samba Member
Joined: September 14, 2011 Posts: 209 Location: Redwood City, CA
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Posted: Fri Aug 17, 2012 9:31 am Post subject: |
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Sir Sam - Wow. Wondering if you've driven the car since applying all the coating? How does it compare to before? Also, maybe this has been touched on, but can these spray on noise dampers serve double duty as a moisture barrier to condensation? Say if you have some rust in the seams, but have taken the time to properly remove it as best as possible using the best known methods, is rust a thing of the past?
Thanks for the video and images! |
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BetaVan Samba Member
Joined: September 14, 2011 Posts: 209 Location: Redwood City, CA
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Posted: Fri Aug 17, 2012 9:33 am Post subject: |
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Quote: |
Wondering if you've driven the car since applying all the coating? |
Er... Van
Don't hate me, my lips just touched my first cup of coffee. |
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ZanaEvyPapa Samba Member
Joined: July 31, 2010 Posts: 255 Location: Gainesville, FL
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Posted: Fri Aug 17, 2012 12:32 pm Post subject: |
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vote for sticky. I know there are a ton of threads on sound abatement, but this one seems to be the most in terms of an actual consensus with facts to back it.
What I would want out of a sticky is a real plan and method for all of us to follow. Something that could be updated as technologies improve and testing is done. Perhaps I'm naive at us coming to a consensus, but the one thing we all have in common is the baseline: a Vanagon, so that should help us at least come up with specific strategies based on the types of products that are available. _________________ 82 Diesel Westy
03 Jetta TDI
Gainesville, FL |
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dubbified Samba Member
Joined: March 03, 2010 Posts: 1406 Location: Redmond, WA
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Posted: Fri Aug 17, 2012 12:43 pm Post subject: |
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I opted for all peel and stick with a heat gun..
The van is so quiet, I cannot hear the engine when on the road, or at idle, all I hear is the stereo and the lady whining its too loud!!
Course, I did the XXtream, fatmat threatment to every bit, Behind the dash, above the front sill under the window, doors, pulled those little bits of dynamat on the rear 1/4s, put in full sheets on inners of doors, and where the doorcards touch the door, hatch, slider, then went to work with Raptor liner on all window frames and jambs, that shut it up.. next to no vibrations. I also think the underbody Wurth underbody did good, used about 10 cans under the van.. next to no road noise, course the tires are quiet too. i think a combination of things is ideal.
a shot after I did the floor..
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grokinthebox Samba Member
Joined: September 24, 2010 Posts: 23 Location: santa rosa, ca
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Posted: Fri Aug 24, 2012 7:04 am Post subject: clarification and wrong part number |
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tclark,
thanks for putting together the great summary. is this still your plan or have you decided to do something else?
I believe you listed the wrong part number below:
should be 032090
Are you intending to spray this compound into the door (at the back of the exterior door panel?
thanks |
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randywebb Samba Member
Joined: February 15, 2005 Posts: 3815 Location: Greater Metropolitan Nimrod, Orygun
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Posted: Fri Aug 24, 2012 2:03 pm Post subject: |
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most spray on materials use micro-ceramic beads embedded in a visco-elastic matrix to dissipate sound into heat
they offer ease of application for large shops, and maybe less wt., but may not dampen as well as a butyl pad treatment
no matter what, you will want to float a layer (usually MLV) over the top of the actual dampening layer
it looks like the stuff dubbufied used is a combination material (foil on top instead of MLV) - it should work well but similar results can be obtained with less material and cost, tho maybe more labor _________________ 1986 2.1L Westy 2wd Auto Trans. |
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PDXSyncro Samba Member
Joined: August 25, 2010 Posts: 135 Location: Portland OR
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Posted: Thu Aug 30, 2012 1:36 pm Post subject: |
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Folks,
I'm restoring my syncro and am working on the next phase of sound proofing. I've got the entire interior (floor, ceiling, and side panels/doors) sprayed with a couple of coats of CAE dampener. I'm now working on getting some composite sound barrier. I've been looking at a number of places and am currently targetting CAE's SB-DFB-20R Closed Cell Foam w/ Vinyl Barrier as the best cost/benefit option.
I'd like to get opinions of anyone who's done an install of composite sound barrier. I chose closed cell over open cell because of the water absorption (5% closed cell/80% open cell). I was also told that closed cell rebound from compression better than open and compresses less because the air is trapped in the cell.
I've calculated about 117 sq ft for the entire install which means 2 rolls of 90 sq ft for me at about $600. Expensive but I could not find a better deal. I could go 90ft roll and some vb-4 sheets that bring me in at about about $500 but for $100 more I could have a lot of excess for other projects so I'm keen to do that.
Anyway comments would be welcome on other products, materials, approaches, etc...
Thanks! |
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denwood Samba Member
Joined: July 29, 2012 Posts: 1047 Location: Thunder Bay, Ontario, Canada
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Posted: Thu Aug 30, 2012 2:17 pm Post subject: |
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There was a post kicking around here by a fellow who did tests before and after sound treatment with not much difference. After doing a ton of research on wall systems and building both a 1000 sq/ft sound studio, as well as 3d projection room in our new building... I have a much better grip on why.
1. To get to the 65 STC rating of our studio, we required double decoupled 2x4 walls, rocksul insulation and resilient channel drywall mounting on both sides. We also installed automatic door jams which drop and seal 100% as the door is closed.The weak point in the studio is however the door and trim due to air leakage. A small air gap (1% of the door) can increase sound transmission via the gap by ~ 40% to 50%.
So first, you must air seal for the best "buzz for your buck". Then the best strategy adds mass to both sides of a double wall, and decouples these masses. Note that metal studs are better than wood in reducing sound..which is pretty much the vanagon body.
I'm going out on a limb here but I suspect that the best strategy would be something like this:
1. Add mass to both inside and outside metal surfaces (the spray stuff would be my choice here to dampen them. The less one surface vibrates, the less you'll see in resonance in the corresponding surface.
2. Add insulation. Rocksul, or what's used in sound control panels, Owens Corning 703 or 705 very high density glass. This is quite effective at lower frequency dampening. We know however that this is good way to trap moisture in interior cavites...so good for sound, not good for rust.
3. Air seal as best as you can. I would postulate that just air sealing the body would be the cheapest way to reduce the most sound.
I'll also stick my neck out and say that anything beyond with respect to products is going to provide a diminishing rate of return. _________________ Cheers,
Dennis Wood
The Grape |
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