I'm building a multipurpose media room and bar in a 400 sq ft L shaped room where the larger space is for AV and the rest is for the bar. This is in just under half of the basement of a house built in 1962. It's a wood framed construction with 2x4 walls 16 OC and 2x8 joists 16" OC, with forced air heating. Above this space is 3 bedrooms. I'm removing the duct work supplies and returns to the room in favor of electric baseboard heaters to eliminate a weak point in soundproofing. I plan to insulate, double drywall with green glue the walls and ceilings, and I might use clips and channel on the ceilings. However, for the remaining ducts in the joist cavities above this room that are feeding the 3 upstairs bedrooms, as well as the main trunk in a soffiit within this space, should I dampen them somehow? I'll be insulating, but that's only absorption. Here's the HVAC layout: I was thinking of dampening all the duct work with this, which I can get in a 5 gallon pail for $150 plus shipping and just paint brush on: http://acousticsubfloorpanels.com/pipesandducts/Dampingmaterial/3603.pdf Kineticsnoise.ca has something similar but it's $255 a pail plus shipping. http://www.kineticsnoise.ca/industrial/pdf/kdce162.pdf Thoughts? Experiences? Am I wasting my money?