I can't take full credit for this, because I just phoned a guy at a ducting supply place. He suggested that I use the plastic dryer output tube as heating ducts for my upcoming home theater. You know, the plastic 5 or 6" pipe with wire spiralling around it for the full length? Or, how about the metal dryer tube, aluminum, but like and accordian and I would assume it will help reduce sound transmission through the duct, but it may also introduce turbulence to the airflow. Perhaps slow down the airflow too much. This all stems from my desire to find a way to inject warm or cooled air from my furnace, into the theater, without allowing sound an easy escape route. I have tried looking for acoustic ducting, or foam and cork material that might be used as a tube liner, but I'm not having the success I'd hoped for. I also thought about taking a long metal section of my ducting, and cutting a section in the middle, then replacing this with a soft sewn material. Sort of like an airport wind sock, but not tapered. I have a bunch of artificial leather, (I used to make hockey equipment in another life) and I could sew a large tube, 3 or 4 feet long, and clamp it onto metal ducts. This would hopefully act like a sound barrier, or a "disconnect" and the vibrations wouldn't travel the full length of the duct. So, as always, I'd like to know, are these ideas workable, or would they fail. And does anyone else have methods of moving air in/out of the movie room without ruining the acoustic containment that the wife will ultimately demand? What have you master builders done to solve the problem? Thanks, Tom, Ottawa Canada.