Which is better dampering mat or foam?

[5thgenaccord 10+ year member]

I was wondering which one I should do for sound deadening? Right now I have second skin damplifer (mat) and it works well. But I was told foam was great for keeping the sound in my car, because you can hear my music easily from the outside. If I were to use foam, which company should I go with, and is there anything special that I should be looking for with foam?

Thanks

Click to read more...

 

[luvinthebass 5,000+ posts]

keep your windows up then, the glass should keep most of the bass inside anyway...but not always, Second Skin products they are amazing and cheaper then Dynamat. give those a try

 

[jmanpc 5,000+ posts]

just depends on the application //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif

 

[reneeb7363 10+ year member]

what you are looking for is obviously 'insulation' from sound waves travelling to another environment from which they are produced. ANY kind of insulation will slow down the movement of sound waves... fiberfill or poly insulation (think pink! LOL) converts the sound waves to energy thusly reducing the available output. Because the nature of the fibrous material mentioned, it would take copius amounts to acheive the desired affect. They (the car industry) do make a vehicle insulation that uses a denser material, usually backed with a rubber sheet.

Matting, aka, sound deadener, increases the mass/weight of an object wich lowers its resonant frequency...in lamens terms, enuff matt = no audible vibration.

and yes, foam will restrict the exchange of distributed frequency but in the long run you would be better off making sure that:

1st- the area in question has been dampened properly with asphalt or rubber matting (dynamat, second skin, etc)

2nd- over said matting install an automotive insulation (like what you find underneath your cars carpeting.)

3rd- use the foam deadening agent in places you cannot apply the 'matt' material.

go to a lexus or cadillac dealer and ask them how they make the inside of the vehicle so quiet (from road-noise) you will see they basically use the same process.

 

[luvinthebass 5,000+ posts]

i remember havin my trunk with no deadener and it could be heard for blocks, put some deadener in the whole trunk area, sounded louder IN the car and no rattles or vibration from trunk lid, still could be heard outside though if my windows were cracked, and i used Second Skin //content.invisioncic.com/y282845/emoticons/biggrin.gif.d71a5d36fcbab170f2364c9f2e3946cb.gif

 

[skydeaner 10+ year member]

there was somebody that took a reading on their setup and gained like 1-2 db's just from installing damping mat of some sort. I **** at searching so I can't find the thread though.

 

[reneeb7363 10+ year member]

my long winded commentary basically meant...anything you use to slow/deaden the sound waves will improve internal sound reproduction due to less lost energy.

use the general search feature (in the toolbar above the advertisement)

http://www.caraudio.com/forum/search.php?searchid=1588187

lots of good stuff

 

[luvinthebass 5,000+ posts]

my long winded commentary basically meant...anything you use to slow/deaden the sound waves will improve internal sound reproduction due to less lost energy.
use the general search feature (in the toolbar above the advertisement)

http://www.caraudio.com/forum/search.php?searchid=1588187

lots of good stuff

Do low frequency waves go through metal or do they bounce off?

 

[reneeb7363 10+ year member]

Do low frequency waves go through metal or do they bounce off?

neither, well, kind-of, umm...no...well...depending on the resonant frequency of the surface in question, the sound waves vibrate the metal, ie: the enrgy of said sound is being expended on the object. And, any 'use' or obstruction of sound decreases it's energy. Even air exponentially reduces the energy of sound.

a few helpful links:

Sound waves, what are they?: http://www.fi.edu/fellows/fellow2/apr99/soundvib.html

http://en.wikipedia.org/wiki/Sound_wave

doppler effect: http://en.wikipedia.org/wiki/Doppler_effect

 

[luvinthebass 5,000+ posts]

hmm interesting thanks for that info

 

[skydeaner 10+ year member]

so if you filled the cabin of a car with helium how many db's would you gain? hehe, jus kiddin.,