What about cork?

Hi Do you have experience with the material cork to reduce reflexions? Eventually this may be a good material even for low frequencys? Thanks Olivier

Olivier, > Do you have experience with the material cork to reduce reflexions? < I have no direct experience with cork, but I'm pretty sure it's not a very good absorber. Certainly not as good as rigid fiberglass which is more commonly used. --Ethan

Olivier - I've had experience with cork back in the late 60s early 70s when it was the main acoustic treatment in the studios of the time here in Australia. We used to use sheets of dark brown cork that was 1" thick and came in sheets 2' x 1' but it was also available in 2" and 3" thickness. Obviously the thicker the better but normal 1" has a NRC of around .85. So it's a reasonable absorber. For those who don't wish to have fibreglass in their rooms because of it's toxic effect (which it isn't but some think it is) it's a reasonable alternative - looks good too :) I am a fan of cork floors though - they wear extremely well, especially around heavy areas like the console and it has some give so cups, glasses and expensive gear doesn't break when dropped. cheers john

Thank you for your answers. I too like the feeling of cork - but the problem is, that cork has a negative eco-balance (as we say in Switzerland :-), I was told. So maybe Im looking for other materials like cotton or flax (shall be a very good absorber). Thanks again, greetings Olivier

John, > 1" thick and came in sheets 2' x 1' but it was also available in 2" and 3" thickness. Obviously the thicker the better but normal 1" has a NRC of around .85. So it's a reasonable absorber. < Thanks for clarifying. The cork I usually see is a very thin veneer meant to be put over a normal wall for appearance only. --Ethan

Yes, Ethan - most people don't realise it's available in thicker sizes. Now that we are dropping the wine corking and going to screwtop there should be plenty on the market. It can look very nice as a wall treament and its easy to lift it off the wall for greater depth. cheers john