[JUDGE3]

anyone use a good lower cost lighter weight alternative to the dynomat sound deadener?

nearing the need for this but I don't need a high end product or that heavy of material.

[455'73inElCamino]

I have used product from NAPA which is a dupont product and also product from eastwood but have no way to tell if it is better. They were definitely less expensive.

My understanding is that the weight of the product is needed to help dampen out noice. The weight aids in lowering the frequency of the vibration, so I understand, I assume to move to a non resonant frequency.

[crazycarlo]

I sis the whole interior of my mustang In a cheap product from Lowe’s called “frost king” it’s made for HVaC ducting. $18 a roll and I’m happy.

[428goat]

I used the Eastwood stuff and am happy

[Chief of the 60's]

Originally Posted by crazycarlo

I sis the whole interior of my mustang In a cheap product from Lowe’s called “frost king” it’s made for HVaC ducting. $18 a roll and I’m happy.

I know people that used roofing ice shield. They seem rather pleased with the end results.

[RA66GTO]

I used Kool Mat and have been very happy with the results.

https://www.koolmat.com/

[Jack Gifford]

Originally Posted by 455'73inElCamino

... My understanding is that the weight of the product is needed to help dampen out noice. The weight aids in lowering the frequency of the vibration, so I understand, I assume to move to a non resonant frequency...

Truth

[JLMounce]

There's a lot of confusion on this subject, so it kind of comes down to what you're wanting to do with the car. Dynamat is not inherently a sound deadener. It should be thought of as a vibration inhibitor (damper). It adds mass and some structure to otherwise thin paneling that can generate sympathetic vibrations.

If you take a look at modern luxury cars and how they are treated with three materials. The first is the damper which is typically a butyl based product like dynamat. Is dynamat inherently better than other butyl based products? Probably not, as long as the product you're applying actively damps resonance in metal panels.

The second product is a decoupler. This is designed to get your seat off of those panels that are resonating with the rest of the car. This product also acts as an insulation and to some extent a sound absorber for what's coming out of those panels you added the butyl product to.

Finally, you have a mass loaded vinyl product. This is the stuff that really does the work of knocking down sound waves. You want to put this stuff basically everywhere. The more you add, the quieter the cabin is going to become. You specifically want to target the doors, firewall and wheels wells, which tend to produce the most sound. There's a cost here though, the stuff is heavy. So your trading quiet comfort for a lot of mass, that's probably not particularly in a good spot if you care a lot about performance.

So you need to make some decisions on what you want the car to be. If you're going full out luxury and you want your muscle car to be a new caddy, go to the moon with this stuff. Do 50-70% coverage of a matt butyl product, full coverage from firewall to trunk panel with a decoupling material like DEI Undercarpet Lite and then go to town with as much mass loaded vinyl as you can shake a stick at.

Just search amazon for acoustic mass loaded vinyl. you'll also need a vinyl contact cement for install.

If however you're not after a modern caddy-like experience, but you're just trying to get rid of some vibrations and squeaks and possibly keep the cabin a bit cooler in the summer and warmer in the winter, You can go for just the matt product and the decoupler. 50% coverage on the matt product and at least full coverage in the cabin area with the decoupler. Then your carpet over that. This will be better than factory, but will leave some of the rawness of the car.

You can do anything in between on that as well based on what you're after.

For my '69 bird I'm going to be doing a bit more than 50% coverage from firewall to tail panel + doors and package tray in a matt product, followed by full coverage of DEI undercarpet lite. Because I'm concerned about weight, and where it's at, I will not be treating the roof with anything and I'm not going to be doing any mass loaded vinyl. I'll likely end up doubling up on the jute backing behind the seat however to try and knock down more road noise from the rear wheel wells and exhaust outlets.

[roy381]

I used nioco liner with good results

https://www.ebay.com/itm/Noico-50-mi...S!-1:rk:5:pf:0

https://www.amazon.com/Noico-deadeni...sound+deadener

[unruhjonny]

Originally Posted by Chief of the 60's

I know people that used roofing ice shield. They seem rather pleased with the end results.

wouldn't this be similar to what was used at the factory - but less than half the depth of the OE product?

I had understood that he OE stuff was a tar paper product - which is exactly what this is.

[rjpaige3]

Check out this site for a lot of good information and advice to maximize the efficiency of your soundproofing.

https://www.sounddeadenershowdown.com/

[GXPJim]

Had good luck with Rattle Trap.

Sent from my SM-G930V using Tapatalk

[mjc34]

https://www.b-quiet.com/

[rohrt]

What I used.

https://store.secondskinaudio.com/damplifier-pro



Wish I would have went all the way up the firewall. And as well as it works it doesn't work well enough to keep the heat out. I think If I had to do over again I would incorporate lizzard skin

[Tim john]

I spent the money and went with Dynamat Extreme. Installed it in the door shells, full floor pans and up the toe kicks to the dash pad, inside the rear quarter window wells (quarter panel insides) and on top of the rear wheel well tubs inside the rear quarter window openings. Amazing on how "solid" the car feels and sounds now. The doors close with an authoritative dense thud and feel rock solid. The exhaust tone is much milder and no uncomfortable heat issues coming for the floor. I am very pleased with the results for the money spent. No regrets to have not "tried" a questionable and possible lesser product.

Tim john---

[tjs72lemans]

I used Fatmat before in a couple cars and liked it. Ordered some for the Lemans and it came today.

[68 Firebird]

For mine I went all in. Used dynamat extreme on interior and firewall. And Dynaliner on top of that. Also covered trunk divider as well behind rear seat. Exhaust is MUCH quieter and very solid overall feel inside car. Too save cost used amazon since I get free shipping. Money well spent!!! Gerry

[389]

I'd like a quieter interior but breathing the chemicals that go into that stuff concern me and I pass...

[JLMounce]

Originally Posted by 389

I'd like a quieter interior but breathing the chemicals that go into that stuff concern me and I pass...

You can use the paper based insulation that the factory used and jute as a decoupling layer. It won't be quite as effective as some of the modern stuff you're seeing in this thread, but it should help quiet things down without adding the butyl rubber based products.

In this case without that constrain layer though, you're giving up basically any chance to limit harmonic and sympathetic vibrations in the floor pans.

What you could do at the expense of a bunch of weight would be to use a bed lining material on the bottom of the floor pans. That would keep the fumes on the outside and would serve as a constrain layer to dampen vibration.

[tjs72lemans]

I've used the Fatmat in two cars. With the foil up and sealing the butly rubber, I've never had a hint of the smell of anything. I have heard some people mention using some of the home improvement materials mention oders though.