I'm trying to find out options for soundproofing a very large industrial garage. The room is roughly 76000 cubic feet (45w x 38d x 20h). There is a large wooden rollup garage door and two large windows (4 x 12 ft). The construction of the walls is brick on two walls and masonry on two walls. I'm looking for a fairly inexpensive way to soundproof the rool up door and the windows so we can keep sound in. We run heavy duty machinery with sound levels that run up to, I'm guessing, 95 db. Any ideas?