Another confirmation of the optimal value of the duro 70 sorb for me : i replace many sorbathane pieces duro 50 and 40 that were under the granite plate that are on top of my speakers +3concrete slabs ( i have already put some days ago 5 pieces of duro 70 under each speakers with great results) The replacement made a superlative difference more clarity and definition....I have duro 70 pieces under and on top of my speakers now rightly compressed...The proof is hearing... The result is so evident then my wife (who hate my audio obsession) hears it immediately, is there a need for better proof? Anywhere on all piece of gear where i put it sorbothane duro 70 is better than the other duro he replace , the problem is that this 70 duro is more dense and it works really better compressed...But on an headphone 1/4 duro 70 correctly glued is better also than any other duro for me, even not compressed, but better if compressed. It is a pity that the message is going out very slowly, for all the poor audiophile like me sorbothane is miraculous...More precisely i will say now sorbothane duro 70 rightly applied is miraculous. By the way all my gear now sound superlatively good and i cannot pick one of them et absolutely prefer it to the 2 others, each of their own potential is optimally stage by the sorb.