# Carpet padding for damping material?



## mrstampe

Seems like just about everything under the sun has been stuffed into speaker enclosures for damping. Has anyone ever used, or heard of, carpet padding being used? I have new 5/8" carpet padding left over after my house was recarpeted. I've actually doubled it up and stapled it into my Nat P cabinets, but have not sealed everything up and taken a listen yet. Any experience with this?


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## Seaxe

mrstampe,I have indeed heard ofdouble layer corrugated foam carpet underlay used as you describe,for cabinet wall damping.The user thereof stated that it performed very well,and saved on build costs in addition.Sorry,I cant recall where I read this,or provide a link, Hope this helps,Mike.


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## fbov

I've used the same in part of my NatP's, along with some of the good stuff, with no complaints. 
Frank


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## ktaillon

It works great for the money in vented boxes. It works much better than box (packing) foam.

A lot of people are using poly foam, which yours may be made out of.


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## ktaillon

You can also try a roofing product called weatherguard, it sticks directly to the wood. Then apply the foam over it. 

This will deaden the panel nicely. It did a great job on my sub.


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## WmAx

I am not certain of the co-efficient of this material. However, the most highly effective (thickness vs. bandwidth) known materials, and used for premium sound control treatments, are high density (4-8lb/ft^3) fiberglass and rockwool board, such as Owens Corning's 703-705 selections of fiberglass or various brands of the rock wool. Assuming the carpet padding above is as efficient(which it probably is not) as these materials, then it needs to layered to far more thick than is shown in the photographs above. For example, the high density OC board at 2" thick would absorb nearly all reverberant/reflective ability from 250 Hz and above, with gradual decreasing ability under this approximate frequency, when mounted directly to a hard/solid backing surface.

Calculate your primary acoustic resonances related to the internal dimensions of your cabinet and apply absorption in sufficient thickness to each specific wall, in accordance to the co-efficient properties of that material.

-Chris


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## 1Michael

I would go with the fiberglass because the carpet padding has alot of chemicals that can leach out...


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