What do you experts make of this how-to-video on preventing sound from passing through ducts? http://www.ehow.com/video_4971322_soundproofing-ventilation.html This is the first time I've heard [or read] anyone suggesting sticking multiple 4ft. long fiberglass ductboard panels lengthwise into straight ducts - rotated at different angles as baffles to keep sound from traveling through round ductwork. Seems plausible, but you guys are the experts... << The author's homepage >> http://www.acousticsciences.com/ Any of you Pacific Northwesterners familiar with the company, studio designs, or the author? Thanks!