How much sound deadening (dynamat etc) is needed?
- Thread starter SadbutTrue
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Cobra5.0Jeep
Member
Z06, where are your seat pan risers? Doesn't look like they're there in that pic
They're not there. He must have removed them, i cut mine down. Tall guys don't sit well in Classic Mustangs.
Z06killinSBF
Member
68stang351
Founding Member
I would call and talk to Dynamat again. I just recently saw and ad that said they have pre-cut dynamat for the interior of classic Mustangs now. I would see if they are available yet because then you would get exactly what you need, you wouldn't even have to cut it. Just peel and stick. They said they would sell it in the whole interior kit form, or in separate parts like just the doors, or just the floors or whatever.
Just something you might check into, seems like it could simplify your project quite a bit.
Just something you might check into, seems like it could simplify your project quite a bit.
Not a bad idea. If they don't really destroy me on the price the time I'd save might be worth it.
Also gotta find a source for the closed cell foam, it seems that most people highly recommend that stuff too...
Z06killinSBF
Member
Check the higher end car audio forums to see what they are using. There is a lot of research already out there.
Any issues with structural integrity? I have a set of 07 Shelby seats I want to put in my 66 coupe but they are way too tall. Even at only 6'1" I don't like my head hitting the metal roof...
Z06killinSBF
Member
Not really. The floor flexes if someone heavy moves around. I plan to make braces from my subframe connectors like the fox body guys have.
oz
Founding Member
I have worked on sound deadening materials for Ford (both as a supplier and now at Ford) and can give you some suggestions for quieting any car.
You first need to understand the materials and what they do:
- Damper (Mass - i.e. DynoMat, etc): Controls low frequency noises like road noise and frame/chassis noise. Mass does very little to control high pitched noise.
- Absorbers (foam, fiber products): Control high frequency noises like wind noise but very little to control low pitched noise.
The best scenario is for you to put the materials in the following order:
Source of the noise --> Absorber --> Barrier --> Absorber --> You.
The theory is that the noise passes through the absorber the first time and much of it is absorbed. What gets through, hits the mass where some of it is damped, some gets through but much gets reflected back into the absorber where it has a second chance to be absorbed. What's left has one more chance to be absorbed before getting to your ear.
This isn't always easy to do so putting a barrier on the body and then covering it with foam or 'shoddy' (shreded clothes formed into a sheet or blanket) works pretty well.
A word on using foam - you want OPEN CELL foam, NOT CLOSED CELL! An abosorber works when a high frequency vibration enters the material and is dispersed as it bounces around the interior of the material (via heat). If you use a closed cell foam, the vibration can not penetrate past the first 'closed' cell. This type of foam acts more like a barrier - a very bad one - since it has little mass.
In our cars, dampers are most beneficial because we have lots of body/frame noise that is easily controlled with mass. We also have so much wind noise that can't be controlled (single weatherstrips, body formations that cause wind noise, large body gaps, exposed wipers, etc) that you're really fighting a losing battle. Concentrate on adding mass.
Hit the areas with the biggest undamped areas. Put mass in the doors, on the fire wall, on the floor, wheel wells, and finally the roof if you have any left over. Put absorbing material in the dash and use a good insulator under the carpet. This will be the best bang for the buck while not adding too much weight.
You first need to understand the materials and what they do:
- Damper (Mass - i.e. DynoMat, etc): Controls low frequency noises like road noise and frame/chassis noise. Mass does very little to control high pitched noise.
- Absorbers (foam, fiber products): Control high frequency noises like wind noise but very little to control low pitched noise.
The best scenario is for you to put the materials in the following order:
Source of the noise --> Absorber --> Barrier --> Absorber --> You.
The theory is that the noise passes through the absorber the first time and much of it is absorbed. What gets through, hits the mass where some of it is damped, some gets through but much gets reflected back into the absorber where it has a second chance to be absorbed. What's left has one more chance to be absorbed before getting to your ear.
This isn't always easy to do so putting a barrier on the body and then covering it with foam or 'shoddy' (shreded clothes formed into a sheet or blanket) works pretty well.
A word on using foam - you want OPEN CELL foam, NOT CLOSED CELL! An abosorber works when a high frequency vibration enters the material and is dispersed as it bounces around the interior of the material (via heat). If you use a closed cell foam, the vibration can not penetrate past the first 'closed' cell. This type of foam acts more like a barrier - a very bad one - since it has little mass.
In our cars, dampers are most beneficial because we have lots of body/frame noise that is easily controlled with mass. We also have so much wind noise that can't be controlled (single weatherstrips, body formations that cause wind noise, large body gaps, exposed wipers, etc) that you're really fighting a losing battle. Concentrate on adding mass.
Hit the areas with the biggest undamped areas. Put mass in the doors, on the fire wall, on the floor, wheel wells, and finally the roof if you have any left over. Put absorbing material in the dash and use a good insulator under the carpet. This will be the best bang for the buck while not adding too much weight.
