Correct me if I'm wrong here, but to my understanding the idea behind using the clay is to isolate the speaker from the door itself. Clay works well for this because it's dense. I don't think you will get the same results from foam and silicon do to the density difference. //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif