A Soundproof Door consists of two parts: Mass and a tight seal. By adding mass to a door, you take the first step to increasing its STC. This mass is what is needed to break up sound waves as they travel through the door. This mass is then reinforced with a tight seal that prevents sound leaking around the edges of a door. These doors are heavily insulated to reduce and block noise pollution. Soundproof Door is made available by us for commercial applications.