A soundproof room that is free-floating won't transmit vibrations from the rest of the house.
If you don't have a suitable space in your home to turn into a soundproof room, you can build yourself a separate room inside a larger space. This is a good project for a basement with the space for a booth but without a separate, pre-existing room. You can build a new room in the house and tie it into the existing structure or build a stand-alone, enclosed space. Does this Spark an idea?
Making Your Plan
Mark out the area you want to devote in your existing room to the new soundproof room. Use tape to carefully mark out the space you want the soundproof room to occupy. If possible, build a room without any perfect 90-degree corners. Angles of 100 to 120 degrees provide a better acoustic shape. One option for achieving this is to build the room in a diamond shape in the corner of your space.
Framing
Build the floor, walls and ceiling out of two-by-four lumber. Place the boards 16 inches apart in all elements of the structure. Build an opening for a door in the wall you want to be the front of the room. Cover the floor and top of the ceiling with three-quarter-inch plywood. Install a 1-inch strip of neoprene rubber between the floor and each wall, the ceiling and each wall and at each corner to prevent sound vibration transmission. It is possible to use at least one existing wall or the ceiling of your existing room to create the new room, but this requires alterations to the structure that require more experience, labor and potentially building permits. Building a stand-alone structure also gives you better soundproofing and the option of dismantling or moving the room at a later date.
Finishing
Cover the exterior walls in a double layer of drywall. Stagger the drywall so that the gaps of the previous layer don't line up with the gaps in the top layer. Next, fill the wall cavities with sound-blocking insulation. Repeat the double layer of drywall on the interior of the room and on the ceiling. Caulk all of the seams with a sound-proofing silicone sealant. Install a solid-core door on the front of the room. Also, because a soundproof room is very nearly airtight, buy a ventilation system from a studio-supply company and install it according to the manufacturer's directions to ensure that an adequate fresh air supply is provided to the room.
Sound Treatments
Treating the space is partially a matter of trial and error. Place a recording source inside the room and experiment as you install sound-proofing foam on the walls and ceiling until you get a sound that you're happy with. Purchase high-quality acoustic foam from a studio-supply store and install it on the walls, ceiling and the interior of the door. Put a layer of carpet down on the floor to muffle any noise from walking on the wood surface. Finally, add any additional sound treatments such as bass traps that might become necessary to treat emerging frequency problems, such as too much low-end reflection.
Tags: build room, soundproof room, walls ceiling, double layer, double layer drywall, each wall, existing room
