Also tossed in some Boston ambient tweets. Basically I filled all of the hollow cavities with a two part closed cell foam, used some 80 mil Fat Mat on areas of vibration, and covered most everything with Mass Loaded Vinyl and CCF. The very large cavities were filled with R-19 fiberglass insulation. All products were weighed before install. less than 100 lbs of material was installed and total cost was less than 200.00. Enjoy the pics.