FYI: This isn’t really a sound “proof” box, but I didn’t think sound dampening box had the same ring to it.
The construction of this box was done entirely with components from my local Home Depot. The total cost was about $200 for this 3ft x 3ft x 3ft box. The main components were:
- 2x4s for box frame
- 1/2 inch plywood for top/bottom (had Home Depot cut these free of charge)
- 10 sheets of 1/8 inch hard board for sides and top/bottom (again Home Depot cut these for me)
- Insulation to help sound proof the box
- Lots of screws and nails
- Hinges and a bolt lock for the door
- 2 8×12 inch pieces of Plexiglass for the door’s window
- Bathroom ceiling fan to suck out hot air from top (surprised that this was only $10)
- Vent to let in air on the bottom
- Cheap light for the box
- Carpet or cloth to attach on the inside to help deaden the sound
I’m not going to detail the exact construction since it will vary depending on the size and options you need. For instance you might not need the fan, vent or window that my project needed.
The first main point about construction that I want to mention is that you should pick insulation that’s at least twice as think as the space between your walls. When you’re using insulation for heat you want to have it loose, but when using it for sound proofing you want it compressed. Another trick is to make sure a large part of the box’s interior is covered with cloth or carpet. I think carpet would be best, but I had some extra felt at home so I just used that.
Here are some pictures of a single wall’s stages of construction.
Here are some pictures of the finished box. I was quite happy with how much quieter my CNC machine is after I put it in this box.