# Knaf EI 475 -- Good acoustic Material?



## 4U2NVME (Aug 20, 2010)

I am looking for different materials to absorb sound and prevent it from reflecting. I found some material that they make Air Vents out of and its properties are below. I have no idea what it all means, does this product work well? I would be putting it up on the wall on top of the Dry wall front wall behind screen. Cutting it and putting it into cloth panels to hang on the wall.










-NV


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## bpape (Sep 14, 2006)

Looks very similar to OC703 specs. It should work fine. If it's for ductwork, there will be a film/coating on one side which is designed to smooth airflow and stop any particles from coming loose in the air stream. That may reflect a bit of high frequencies so I'd likely turn that toward the wall and expose the other side.

Bryan


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