acoustic flooring underlay
12-15-2008, 05:19 PM
#1
0 Watt CAFz'r
Thread Starter
Join Date: Nov 2008
Posts: 5
acoustic flooring underlay
Anyone have any thoughts on using acoustic underlay for sound deadening doors. Closed cell and claims of impact sound reduction up to 21 dbs has me wondering if these products might be useful for budget conscious installs.
here's an example
http://www.envoyflooring.com/en/products/envoy-sonic
here's an example
http://www.envoyflooring.com/en/products/envoy-sonic
12-15-2008, 06:56 PM
#2
Yankee
Join Date: Oct 2003
Posts: 3,599
1. no such thing as sound deadening (it is an ad-copy term that means everything yet says nothing), what you are looking for is called sound isolation. Sound isolation provides what is commonly referred to as 'transmission loss'. The amount of transmission loss (TL) is determined through ASTM E90 and is represented by an STC number the higher the number the better (as you read through the misleading ad-copy make sure they use ASTM E90 to develop their STC number and not some other test) this way you can compare apples to apples
2. The product described is probably used in your car already, I have a foam and hard plastic sound isolator. Some cars use a hard shell on the underside of their carpet over a foam. Many use jute which is essentially used blue jeans. Most TL is constrained layers soft foam then hard plastic.
3. This is not what you think of when you hear the brand dynamat (though their trunk and hood kits use stuff like this), dynamat (brown bread, second skin) is famous for damping materials. You will also find this on many new cars. There is a TL factor though in the dampers especially with the metal skin.
4. To answer your question it will make your car less susceptible to road noise, it is a good thing to have (though the products your looking at are for home theater). The impact noise it is trying to remove BTW is foot steps. Lots of good retail products out there that do what your looking for.
Their claim of 21 dB is near fantasy in a house (and I am being kind), and in a car I think you would be lucky to get 5 dB and that is if you used a lot of $.
2. The product described is probably used in your car already, I have a foam and hard plastic sound isolator. Some cars use a hard shell on the underside of their carpet over a foam. Many use jute which is essentially used blue jeans. Most TL is constrained layers soft foam then hard plastic.
3. This is not what you think of when you hear the brand dynamat (though their trunk and hood kits use stuff like this), dynamat (brown bread, second skin) is famous for damping materials. You will also find this on many new cars. There is a TL factor though in the dampers especially with the metal skin.
4. To answer your question it will make your car less susceptible to road noise, it is a good thing to have (though the products your looking at are for home theater). The impact noise it is trying to remove BTW is foot steps. Lots of good retail products out there that do what your looking for.
Their claim of 21 dB is near fantasy in a house (and I am being kind), and in a car I think you would be lucky to get 5 dB and that is if you used a lot of $.
Last edited by JohnVroom; 12-15-2008 at 07:04 PM.
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