Procedure

Think of sound waves in a similar way to how you would think of light waves. They radiate from a source into a room, reflect off some surfaces, are absorbed by others, and lose energy as they travel further from their source. Sound waves are more challenging though, in that they cannot be seen. This makes it is very difficult to predict how a given room will act acoustically. So, try to build a room minimizing acoustic reflections at the source. 

A baffle wall will reinforce low-frequency energy without increasing the amplifier power. This increases efficiency and creates a better sounding system. 

1. The best way to build a cinema baffle wall is to think of it as an interior stud frame partition wall. 
2. Add several layers of 5/8-inch gypsum with overlapped joints, each layer screwed individually to studs.  
3. Face the final layer with at least 1 inch of sound absorption material, such as Johns Manville Permacote Linacoustic RC-HP duct liner (1.5 lb per cubic foot), installed with the black side facing the screen. 
4. Any hardware used to attach the duct liner to the gypsum must be spray-painted flat black. 
5. Wall to wall and floor to ceiling is optimal, since it prevents any sound reflections from penetrating the screen and invading the seating area, which can affect dialog intelligibility decrease low-frequency output.