When deadening isn't enough.
Thread Starter
Team Owner
Joined: Feb 2000
Posts: 51,504
Likes: 6
From: Sacramento CA
When deadening isn't enough.
The back wall is really bugging me.
So far I have 6 layers of liquid, and 1 layer of sheet damping. This is THICK, and probably about as thick as I can go, but... The panel is still really bad. It has a nice low thunk, but my IDMAX will vibrate this thing like a reed, I know it.
And what's worse, is the section behind the seats that I haven't even started with...
This car is going to flex like a balloon if I don't do something...
Has anyone affixed balsa wood to the bad sections? I know the floors are very stiff, and GM sandwiched balsa in. My thought is to apply liquid damper, a layer of balsa, then a layer of sheet damping. This might allow a combination of damping and barrier that could make these panels "not so bad."
But I'd need to find 1/8" balsa wood sheets, which I'm having trouble finding...
Has anyone done something similar to this? Maybe something better than balsa? Cork?
Furthermore,
Wouldn't a cork gasket under the speaker rim, as well as a cork gasket around the MDF speaker mount reduce vibration that the door panel is subject to? This stuff is probably better than using dynamt type material for such an application. Though there has to be a reason people aren't using it.
So far I have 6 layers of liquid, and 1 layer of sheet damping. This is THICK, and probably about as thick as I can go, but... The panel is still really bad. It has a nice low thunk, but my IDMAX will vibrate this thing like a reed, I know it.
And what's worse, is the section behind the seats that I haven't even started with...
This car is going to flex like a balloon if I don't do something...
Has anyone affixed balsa wood to the bad sections? I know the floors are very stiff, and GM sandwiched balsa in. My thought is to apply liquid damper, a layer of balsa, then a layer of sheet damping. This might allow a combination of damping and barrier that could make these panels "not so bad."
But I'd need to find 1/8" balsa wood sheets, which I'm having trouble finding...
Has anyone done something similar to this? Maybe something better than balsa? Cork?
Furthermore,
Wouldn't a cork gasket under the speaker rim, as well as a cork gasket around the MDF speaker mount reduce vibration that the door panel is subject to? This stuff is probably better than using dynamt type material for such an application. Though there has to be a reason people aren't using it.
Last edited by Kale; Dec 18, 2006 at 11:37 AM.
Safety Car
Joined: Jan 2006
Posts: 3,566
Likes: 4
From: Mt Laurel NJ
St. Jude Donor '06-'07
There is a book, "101 Projects for your C4" in which the author recommends putting cork under the rugs in the rear of a coupe to reduce the sound levels and make the car quieter. I think it would work well. Have you thought about adding a Crazy Cowboy kit over the liquid sound deadening?
Thread Starter
Team Owner
Joined: Feb 2000
Posts: 51,504
Likes: 6
From: Sacramento CA
There is a book, "101 Projects for your C4" in which the author recommends putting cork under the rugs in the rear of a coupe to reduce the sound levels and make the car quieter. I think it would work well. Have you thought about adding a Crazy Cowboy kit over the liquid sound deadening?
Racer
Joined: Mar 2006
Posts: 366
Likes: 1
From: Esparto ca
Hi kale, I agree, these fiberglass panels are thin. I think you'd be better off starting where the factory left off. Scuff the panels with 24 or 36 grit use epoxy resin and fibrglass mat. 2 layers of mat and epoxy resin will give you more stiffness than the balsa. You could go even further by getting some 1/8 or 1/4" thick strips of fiberglass and put them on top of the mat between the ridges.
Thread Starter
Team Owner
Joined: Feb 2000
Posts: 51,504
Likes: 6
From: Sacramento CA
I'm not sure I'm up to tearing it down that much. 
I think the liquid stuff did an OK job of stiffening, for what it is. It dries inflexible, which is one of the reasons I like it over dynamat type material.
I think the liquid stuff did an OK job of stiffening, for what it is. It dries inflexible, which is one of the reasons I like it over dynamat type material.
Melting Slicks
Joined: Dec 2004
Posts: 2,394
Likes: 0
From: Bay Area CA
EG no one will ever call "under engineered" on your projects 
The cork is acting as a decoupler I am guessing? I just am not sure that wood, which resonates in its own way especially at that thickness is the answer. I guess if you went and decoupled each layer (IE factory glass > liquid deadener > "dynamat" > closed cell > wood > dynamat? )
Have pics of the install yet? Kinda curious what it looks like ... might be easier to help
Fej
The cork is acting as a decoupler I am guessing? I just am not sure that wood, which resonates in its own way especially at that thickness is the answer. I guess if you went and decoupled each layer (IE factory glass > liquid deadener > "dynamat" > closed cell > wood > dynamat? )
Have pics of the install yet? Kinda curious what it looks like ... might be easier to help
Fej
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
Top 10 Most Expensive Corvettes Ever Sold on Bring A Trailer
Brett Foote
10 Things Every Corvette Owner Needs (2026 Edition)
Michael S. Palmer
8 Most "Only Corvette Owners Understand" Quirks and Problems
Pouria Savadkouei
10 Reasons the C6 Z06 is Still A Performance Benchmark After 20 Years
Joe Kucinski
How Much Horsepower Every Corvette Engine "LOST" in 1972
Joe Kucinski
Top 10 DOs and DON'Ts for Protecting Your Convertible Top!
Michael S. Palmer
Top 10 Most Explosive Corvettes Ever Made: Power-to-Weight Ratio Ranked!
Joe Kucinski
150 hp to 1,250 hp: Every Corvette Generation Compared by the Specs That Matter
Joe Kucinski
8 Coolest Corvette Pace Cars (and Replicas) of All Time
Verdad Gallardo
Le Mans Master
Joined: Aug 2005
Posts: 7,201
Likes: 0
From: DP(oh you know where) IL
St. Jude Donor '06
is the idmax gonna be in a box? what im thinking is that with the weight of the sub and box, that could be enough mass in itself to reduce vibrations. Am I thinking right? or am i just not anywhere near the right direction. 
I also remember that once th ecarpet is all back on. it does a descent job of absorbing vibrations.
I also remember that once th ecarpet is all back on. it does a descent job of absorbing vibrations.
Thread Starter
Team Owner
Joined: Feb 2000
Posts: 51,504
Likes: 6
From: Sacramento CA
Yeha, I'd only apply the extra material to the back wall and behind the seats anyway, the rest isnt as bad, so far.
It's going into a 3/4 mdf box, but the IDMAX is easily capable of distorting body panels.
of course, this may all be useless, since if I make those panels PERFECTLY stiff, there isn't anything I can do about the roof...
It's going into a 3/4 mdf box, but the IDMAX is easily capable of distorting body panels.
of course, this may all be useless, since if I make those panels PERFECTLY stiff, there isn't anything I can do about the roof...
Last edited by Kale; Dec 18, 2006 at 02:03 PM.
Supporting Tuner
Joined: Sep 2004
Posts: 51,896
Likes: 39
From: ================== Houston, Texas www.englandgreen.com ================== Necessary Evil™ __________
CI 6-7-8-9-10 Veteran
St. Jude Donor '05-'06-'07-'08-'09-'10-'11-'12-'13-'14
I removed my gas tanks so I could eDead v3 plus 1SE on both sides of the panels behind the seats. I covered the entire bottom of my car in eDead v3 (liquid)
Le Mans Master
Joined: Aug 2005
Posts: 7,201
Likes: 0
From: DP(oh you know where) IL
St. Jude Donor '06
I was thinking about doing that too actually. But i just havent gone through with it yet too many idea and plans, but no budget to do it 
Thread Starter
Team Owner
Joined: Feb 2000
Posts: 51,504
Likes: 6
From: Sacramento CA
I'm planning on painting the bottom under the seats with v3 as well.. .curious how its going to hold up, though. I'm definitely removing the mufflers and getting the "bulges" since I didnt do much damper on the inside of them.
Edesign said not to apply to exterior surfaces, so the worst it can do is fall off, I guess.
Edesign said not to apply to exterior surfaces, so the worst it can do is fall off, I guess.
Last edited by Kale; Dec 18, 2006 at 02:57 PM.
Melting Slicks
Joined: Dec 2004
Posts: 2,394
Likes: 0
From: Bay Area CA
Probably better to use an underspray material than the edead .. or maybe edead then some sort of underspray specific, or bedliner type spray for the outside.
Put a 1" face (sub mount) on that box bro .. its gonna need it
Fej
Put a 1" face (sub mount) on that box bro .. its gonna need it
Fej
Thread Starter
Team Owner
Joined: Feb 2000
Posts: 51,504
Likes: 6
From: Sacramento CA
Good point. I'm at 3/4 right now, but I'm going to space it out with a ring. I'd best put some supports in at least.
I think I may also drill through the car and bolt the box in.
I think I may also drill through the car and bolt the box in.
Supporting Tuner
Joined: Sep 2004
Posts: 51,896
Likes: 39
From: ================== Houston, Texas www.englandgreen.com ================== Necessary Evil™ __________
CI 6-7-8-9-10 Veteran
St. Jude Donor '05-'06-'07-'08-'09-'10-'11-'12-'13-'14
I'm planning on painting the bottom under the seats with v3 as well.. .curious how its going to hold up, though. I'm definitely removing the mufflers and getting the "bulges" since I didnt do much damper on the inside of them.
Edesign said not to apply to exterior surfaces, so the worst it can do is fall off, I guess.
Edesign said not to apply to exterior surfaces, so the worst it can do is fall off, I guess.
I used v1SE first then v3 over that - so I figure if v3 falls or flakes off, v1SE will still be there 
Supporting Tuner
Joined: Sep 2004
Posts: 51,896
Likes: 39
From: ================== Houston, Texas www.englandgreen.com ================== Necessary Evil™ __________
CI 6-7-8-9-10 Veteran
St. Jude Donor '05-'06-'07-'08-'09-'10-'11-'12-'13-'14
Drifting
Joined: Oct 2006
Posts: 1,701
Likes: 0
From: Heath Texas
St. Jude Donor '12-'13-'14-'15-'16-'17
I have used the products from Second Skin and been very impressed. http://www.secondskinaudio.com/cgi-bin/index.cgi They have a three step process. I have used the Damplifier Pro (plus a speaker kit) and the Overkill Pro, but nothing from the Silencer series. I have the Crazy Cowboy Kit in and then the Overkill Pro. Mainly because of weight issues, I haven't put down dampener over the entire car. I have the Damp Pro in the doors and plan on covering it with Overkill, just haven't done it. The Crazy Cowboy Kit and the Overkill Pro are pretty light comparatively, so that is what is in the rest of the car. The front stage sounds great. No real rattles except the trunk lid and the mirror with hard base hits. You can hardly hear the stereo outside of the car with the doors closed. If the rattles are from distinct frequencies then the different products designed to kill those freqs might be helpful. Second Skin has a forum that might be helpful also http://www.secondskinaudio.com/forums/index.php There are some pretty knowledgeable guys on it, certainly more than I; and the owner is quite helpful as well.
Speed
Speed