Sound deadening

[D'Ecosse]

Here is a great article on Sound Deadening and review of the different materials available on market. http://www.sounddeadenershowdown.com/
If you think that is perhaps biased towards the 'winners' in the conclusion, see here - look down to post #6 by the author of that report.

After reviewing this article I did further research & was impressed by Second Skin products. I discovered that there is a substantial incentive (-20% discount!) just for joining their forum! The forum itself has a lot of good information about sound damping & deadening.

This is next phase of my project to do a substantial program in damping, insulation & isolation! Floor, roof, firewall & a re-do of the doors are all on the agenda. We're fortunate that the NSX has a small cabin - this can get expensive in a hurry!
Look for pics in a while!!!

Usual disclaimer applies - absolutely no affiliation of any kind with these products other than I am about to be a customer. All of my opinions are purely from research & as yet unproven!

 

[mr_spanners]

Great website.... read it all... and I need to spend money now!!! :biggrin:

On a serious note though - sound deadening makes a MASSIVE difference in sound quality. I'm planning to do a comprehensive job on the NSX and earlier today I used my 'beater' to test the effects of sound deadening using some basic (very thin) materials....

The results are remarkable! Firstly, the doors now shut with a resounding 'thunk' and the bass response is much deeper and more precise. There is now no resonance, buzzing or rattles coming from the doors and I've also found I don't need to crank the volume up quite as much as I used to. Given I've only used some cheap matting I expect the results from using the Damplifier Pro to be nothing less than spectacular!!!

~Phil.

 

[Autophile]

Thank you D'Ecosse, this is great information. :smile:

 

[sjones]

I just have my doors dynamat'd and it made a huge difference with the stock system.

 

[Malibu Rapper]

I've used McMaster Carr products in the past with great results. They had a product that was exactly the same thing as Dynamat, just without the logo. They stopped carrying it for whatever reason, maybe Dynamat bought the rights to it. It was significantly cheaper.

However, they do still carry a lot of sound products. If you go to their website and search for 9709t19, it will take you to a page with several sound products. The 9709t19 is an asphalt based damping sheet with .07" thickness and an adhesive backing. The sheet runs $14.62 which works out to be about $1.21 per square foot. Very cheap and effective! Do a search on "sound" and you will find several other sound damping products.

Damping a car is a lot of work. I hate doing it.

 

[D'Ecosse]

.... The 9709t19 is an asphalt based damping sheet with .07" thickness and an adhesive backing. The sheet runs $14.62 which works out to be about $1.21 per square foot. Very cheap and effective!

Worth reading the report Bradley .....

Re Pricing -

Dampifier Pro is ~ $3.33 / ft^2
Damplifier is ~$1.87 / ft^2
BXT is ~ ~$1.90 / ft^2

So yes, the McMaster Carr product is 33% cheaper than Damplifier or Raammat BXT but those are Butyl vs the asphalt of the McM-C.
Certainly though the McM-C product is indeed probably comparable with regular Dynamat so please don't spend the extra money on Dynamat just to get the blue logo! So if you are satisfied with asphalt based then yes, good find Bradley.
However if you live in extremes of temperature (very Hot or Cold or both!) then recognize the limitations - not to mention the smell!

Extract from the report conclusion (but please read the whole review)

Highest Quality

Second Skin's products live up to their "Over Engineered to Over Perform" motto. They are clearly a higher quality alternative to Dynamat Xtreme - designed for greater heat tolerance, with higher quality materials.
If quality is your most important requirement, Second Skin Damplifier or Damplifier Pro are the obvious choices. Dynamat Xtreme is close, but being more expensive and not as good isn't a winning combination. I congratulate Second Skin Audio for their obvious dedication to providing the best product possible.

Best Value

RAAMaudio's RAAMmat BXT is a high quality product priced to compete with asphalt mats. If you are considering an asphalt sound deadener based on price, please reconsider.

If you really need to do this in the absolutely least expensive way and are not convinced or concerned by the demonstrated inferiority of asphalt based sound deadeners, go to Home Depot or Lowes and get a roll or two of Peel & Seal. This is the least expensive option and you won't have to worry about shipping costs. I can see no difference in Peel & Seal and the asphalt based aluminum skinned products in this review. If you are going to live dangerously, do it right.

 

[Malibu Rapper]

I just skimmed through the report, nothing really surprised me. I am aware of the differences between butyl and asphalt as far the material superiority goes. But when you try to deaden sound, you want to add weight to it and the weight on the Second Skin product is about 40% lighter than the Dynamat/McMaster product. The other method of sound absorption is turning the waves into heat which is something that none of these products would do very well.

The Second Skin product looks good and I think you'd have a very easy time installing it vs the thicker McMaster Carr product. Maybe I missed it but the website did not go into which product absorbed sound better, it was more of a physical comparison. I use Dynamat Extreme on my doors but I know full well that it doesn't work as well as the Original because of the mass factor. But it is a lot easier to install. Soundoff cars will use double or triple layers for that reason. When Original is installed properly, it doesn't fall apart in most conditions but it does stink for a while. It takes a lot of patience with a roller and a heat gun to do it right.

I used to have a roll of this butyl roofing product that was really easy to install, I'll have to find the info on it too. But it was easy to install because it was soft and thin and you would need two or three layers for it to be effective. Mass should be an important consideration to take as well...

 

[D'Ecosse]

Another important step:

I believe that they (damping mats) are better barriers than they are absorbers. In most situations the best step after damping unwanted energy transfer with our mat is adding some sort of absorbing material, both on top of the deadening material and in places that adding weight will not help. Acoustic foam is the usual way go. The object is to absorb those unwanted sounds that are not blocked or damped by the previous step and to reduce sound reflection inside the vehicle, resulting in a more inert environment.

 

[WOODY]

do you think putting these products on the firewall between the engine and cabin would reduce cabin noise significantly? It would cover ECU, tcs and the other components back there.

 

[D'Ecosse]

do you think putting these products on the firewall between the engine and cabin would reduce cabin noise significantly? It would cover ECU, tcs and the other components back there.

I am going to use the Luxury Liner or OverKill under the trim panels.
I'm on the fence regarding application of either a mat or liquid dampner product there - lot of work to strip everything off first!
I may try the acoustic barrier & see how that goes by itself first.
The OverKill is going in the doors and the Luxury Liner for sure on the roof & maybe also the floor and then one of those products behind the rear trim panels

 

[WOODY]

Can't you just cover all the stuff attached to the firewall with the dampner and then replace the panels over it? It seems as though you could put a couple layers thick and the panels would still snap into position.

 

[D'Ecosse]

Can't you just cover all the stuff attached to the firewall with the dampner and then replace the panels over it? ....

Are you talking about laying the mat directly over the components & wiring harnesses etc? Ouch!
(I'm not sure if you're confusing dampner & acoustic inhibitors)
To do it properly you need to disconnect everything, remove the electronic modules & lay the mat (or paint on the liquid stuff) on the firewall, then re-assemble.
You can certainly lay acoustic foam between the components & the trim panels if that's what you meant. If your main object is to isolate the engine noise then the acoustic foam will probably achieve that by itself - particularly if you use the luxury liner.

 

[WOODY]

Is the dampner the sticky silver stuff vs. the foam matte inhibitor? what is the problem with just covering all that stuff (ECU etc..)...heat?, or does the dampner stick permenantly the everything beneath it? I was hoping to use a combination of both inhibitor(foam) and dampner (silver tape)to maximize the effect.

 

[Briank]

There is already a foam insulation on the bulkhead and I would not apply anything over any of the control equipment. You may be able to add a layer under the ecu, ...

 

[D'Ecosse]

Is the dampner the sticky silver stuff vs. the foam matte inhibitor? what is the problem with just covering all that stuff (ECU etc..)...heat?, or does the dampner stick permenantly the everything beneath it? I was hoping to use a combination of both inhibitor(foam) and dampner (silver tape)to maximize the effect.

Well subsequent access to those components for one and certainly heat would be another.
Yes the dampner is the butyl/foil membrane or alternatively you can paint on a liquid material which subsequently hardens. Either of those should go directly on the substrate (the firewall skin) and the components & harnesses on top of that. It will also look a whole lot neater & professional that way!
I would apply the foam acoustic inhibitors to the trim panels themsleves .

 

[WOODY]

I was thinking add the luxury liner to the back of the panels with adhesive , and also line the entire firewall with 2 sided tape around the perameter and cover with a second single large piece of luxury liner. the panels would still fit easily even with the double layer and I hope to not have to access that stuff in there very often.

 

[D'Ecosse]

I think one layer on the panels should be sufficient and either method will work. Onthe panels makes access easiest as the material will come out when you remove them.
You know of course you won't need access in there .... until you cover them up! Sod's Law

If you want to do something on the firewall, use the Damplifiier (or Pro) mat or Spectrum liquid, but remove the components first and don't cover anything up.
Check out the forums at Second Skin and you will get some tips there. Also good for 20% discount for joining the forum so worth it just for that!

 

[ryans]

Ace Hardware sells rolls of weatherstripping for $7. According to a famous NSX stereo guru it's just as good as Dynomat.

 

[D'Ecosse]

Hey I thought I recognized those speaker mounts, then got the source on your sexygarage site - Craig Hardy.
Does nice work from what I have seen.

 

[johnny010]

Any update here?

 

[ryans]

Any update here?

Updates for what? My speakers rock!