Whatever you use, MAKE SURE THAT IT'S FIRE-RETARDANT (or is treated with a fire retardant spray)! As the tragedy in Warwick, R.I. showed, some accoustic material can ignite and burn like napalm, while also spewing a variety of toxic fumes (phosgene which is similar to "Mustard Gas" of W.W.1, and cyanide). Enjoy, but be safe!
Cork as an acoustical ceiling block
I'm trying to come up with a cost effective solution for my existing HT ceiling. It is only 100" high so I really don't want to add a channel and drop new sheetrock to minimize the noise to the family room above. I'm thinking about going with cork - Seems to have great absorbtion qualities and looks cool too? Has anyone tried this?