Rubber Vs Mastic Sound deadner

[MikeStang 247]

Okay Gents now that my car has been on the road a while I have decided that even tho I have lizard skin sprayed on inside and out on my car along with Dynamat on the entire inside that I still need the thick underlayment that goes on under the carpet.

Here is my problem however.

I see kits that are made of rubber and kits that are made of Mastic.... If I understand correctly our cars had a Mastic or Asphalt type of sound deadener under the carpet which also was supposed to help prevent rust while at the same time stopping sound.

I could care less about stopping the rust since I have the entire undercarriage coated in POR 15 under the lizard skin.

I want the MAXIMUM sound killing material that I can put.... SO... Whats everyones thoughts on Mastic kits Vs Rubber kits that are cut for our cars.

There is only about a 25.00 price difference to go from rubber to mastic but once again I want the best thing for stopping the noise

And GO.....

[MikeStang 247]

No one?

[Shep69 149]

I was thinking about using dynamat . I'm currently have the underlay with the bitumen inner and it's not great . Are you saying dynamat isn't much chop either.

[indianfiremach 170]

It's hard to stop the sound, products like Dynamat do help out with the vibration though. I used Dynamat on my car and a layer of heat insulation and the vibration and heat were both cut down noticeably. Night and day difference. Sealing your firewall will make the biggest difference to keep noise from getting in. Also spending extra time to make sure your windows are propertly aligned also helps.

[Ridge Runner 1,113]

The factory sound deadener was a type of tar mat ,the problem was the jute fibers on one side. If the mats were in the car with the jute down they would hold water and rust out the floors .If they were tar side down they would keep an oily film in the floor pans and the floors were usually preserved . I like the tar type my self .I have had a couple of Mach 1s that had double sound deadener in the floors from the factory .

[Alan_Mac 48]

I used B-Quiet Ultimate on my floor front to back.  I would like to add Vcomp .  Stuff is great at a fraction of the cost of big name brand and is comparable.   

 

http://www.b-quiet.com/pages/product-comparisons

[69RavenConv 286]

I used the asphalt type carpet underlayment that's been available from the usual vendors for years. I can't say the sound deadening is anything special but then I don't have anything to compare it to. Add to that I always have the top down and I get the "Mustang drone" from the cheap turbo mufflers I installed.

[MikeStang 247]

I Have the following done.

 

1. Inside and out Coated with POR15

2. Lizard Skin inside and out to include the trunk sprayed, along with the roof and inside the doors

3. Dynamat from 1/2 way up the  Firewall to the trunk... But Trunk isn't dynamatted just Lizard Skin...Also have a layer of Dynamat on the roof, and in both doors and over wheel well humps.... I figured with this much mat it would be quiet and cool but I can feel the heat on the floor boards after driving for an hour or so through the carpet getting warm, and my exhaust isn't even tucked up close lol.

I was wanting to use the rubber or Mastic mats in the floor on top of my Dynamat and then install the original firewall insulation up the firewall even tho its sprayed with lizard skin from top to bottom.

I get exhaust noise and I want this thing to be Graveyard quiet AND COLD with the windows up.... The AC can barley keep up with the outside temps in the high 90s.

[Mach1 Driver 560]

I Have the following done.

 

1. Inside and out Coated with POR15

2. Lizard Skin inside and out to include the trunk sprayed, along with the roof and inside the doors

3. Dynamat from 1/2 way up the  Firewall to the trunk... But Trunk isn't dynamatted just Lizard Skin...Also have a layer of Dynamat on the roof, and in both doors and over wheel well humps.... I figured with this much mat it would be quiet and cool but I can feel the heat on the floor boards after driving for an hour or so through the carpet getting warm, and my exhaust isn't even tucked up close lol.

I was wanting to use the rubber or Mastic mats in the floor on top of my Dynamat and then install the original firewall insulation up the firewall even tho its sprayed with lizard skin from top to bottom.

I get exhaust noise and I want this thing to be Graveyard quiet AND COLD with the windows up.... The AC can barley keep up with the outside temps in the high 90s.

I too like the car quite and getting it cool is always a problem. How well did you achieve your goal? What else have you tried?

[MikeStang 247]

Well I installed Dynamat in the trunk and on the deck lid and on the package tray, as well as built a new package tray out of foam board, and covered it with a padded black vinyl and it helped reduce the noise SOME but at 60-80 Im still getting the exhaust drone and road noise that I hate...MAy try some different mufflers, as these Borla Pro-XS mufflers are a bit loud for my taste I think.

May be time for some Dynamax Super Turbos like I had on my Trans Am

[Mach1 Driver 560]

Well I installed Dynamat in the trunk and on the deck lid and on the package tray, as well as built a new package tray out of foam board, and covered it with a padded black vinyl and it helped reduce the noise SOME but at 60-80 Im still getting the exhaust drone and road noise that I hate...MAy try some different mufflers, as these Borla Pro-XS mufflers are a bit loud for my taste I think.

May be time for some Dynamax Super Turbos like I had on my Trans Am

Wow it sounds like you've insulated and deadened about everything you can. Please let us know how this goes with the mufflers.

 

I got into a discussion about this about 20 years ago with another engineer who thought some car manufacturers were using the car's sound system to actively cancel unwanted noise. I think he may have been prescient. This is being done today but only at the OEM level as far as I can tell. Go to silentium.com and check out their Quiet Bubble. They use microphones situated around the car and speakers in the headrests to cancel the noise.

[MikeStang 247]

Wow, now that is interesting.

 

I learned a bit about sound deadening and panel loading...

Essentially Dynamat and all the other stuff like it generally are just used to Panel load, which to me makes the panel feel more dense and it cancels vibration and harmonics to a point, the tin foil also helps to reflect heat to a small degree.

The Lizard Skin may have been a waste of money IMHO because of the prep work, the mess, and having to tap every damn bolt hole I came across that the stuff got into.

My best friends 69 Mach has just Dynamatt in most of the same spots as mine, but he didn't do it on the Roof panel and on the insides of the doors like I did his carpet is the same as mine and he has a Fold Down to boot and his car still sounds quieter than mine, altho he has Magnaflow mufflers not Borlas.

[Mach1 Driver 560]

MikeStang, I was just wondering if Dynamat in the doors will hold water and promote rust, or is it sealed in some manner?

[MikeStang 247]

I put it on the inside of the door only on the Backside of the Door Skin vertical surfaces.

Its an oil based product so I cant see it helping to promote rust...If anything it should help protect it.... It really doesn't matter tho because I coated the entire inside of both doors with POR 15 after I had the new shells blasted so the POR 15 would adhere, and then scuffed the POR 15 and sprayed lizard Skin in the doors as well...

I don't think you guys understand LOL If it was metal it got blasted, POR 15, Lizard Skinned, and almost every surface inside the car ALSO Got Dynamat.... The underside of the car actually has POR-15, Lizard Skin and another Layer of POR 15 Sprayed on the lizard skin because the lizard skin is a nasty gray color.... I really think I went a bit overboard on the sound deadening but its not as quiet as I want it to be.

[Mach1 Driver 560]

I put it on the inside of the door only on the Backside of the Door Skin vertical surfaces.

Its an oil based product so I cant see it helping to promote rust...If anything it should help protect it.... It really doesn't matter tho because I coated the entire inside of both doors with POR 15 after I had the new shells blasted so the POR 15 would adhere, and then scuffed the POR 15 and sprayed lizard Skin in the doors as well...

I don't think you guys understand LOL If it was metal it got blasted, POR 15, Lizard Skinned, and almost every surface inside the car ALSO Got Dynamat.... The underside of the car actually has POR-15, Lizard Skin and another Layer of POR 15 Sprayed on the lizard skin because the lizard skin is a nasty gray color.... I really think I went a bit overboard on the sound deadening but its not as quiet as I want it to be.

Yep, no doubt about it, you're an engineer! My motto is: "Too much is never enough".

[MikeStang 247]

Guilty as charged :p

[buening 63]

Have you looked into sourcing mass loaded vinyl and closed cell foam?  Thats what the pro's use atop the dynomat. The closed cell foam isn't too hard to find, but MLV is heavy and shipping gets expensive so you'd have to find it locally.

 

You may have read it already, but this may help:  https://www.sounddeadenershowdown.com/faq-questions-top