Almost without exception, the most common challenge recording engineers face in any professional or home studio is isolation of sound. Even the slightest noise picked up by a microphone can make any recording sound unprofessional, even though it may be made with music being recorded by a professional musician or artist. The answer to this problem is to build a quality isolation booth where no sound entering the booth from outside it is likely to be picked up and recorded. However, building this kind of room takes specialized material and knowledge. If you plan to build your first sound isolation booth, the information below will be of help to you.
Choose your Booth Location
Noise is a factor to consider when choosing your booth location. You will absolutely need to avoid building your booth in any location that will be near any noise producing equipment or material such as HVAC equipment or ducts, water pipes, heating vents, etc. The best place for your booth will be in some quiet, out-of-the-way place.
Generally, a room 6x8-feet with an 8-foot ceiling will work fine. You can build a larger room, but in comparing use versus expense, you'll be better off if you keep the room smaller.
Place enough pieces of 4x4-inch boards around the perimeter of the room so that they extend completely around the room, except for doorways. These boards will be the floor plates you attach the wall studs to. The narrow edge of these boards should be facing upward. Cover your floor with tarp or plastic sheets over the entire floor area of your booth.
Next, spread enough sand on top of the plastic or tarp that the top surface of the sand is at the same level as the top surface of the 2x4-inch boards you laid around the edge of your booth area. Finally, lay your plywood across the sand with their edges resting on the boards at the edges of the booth area.
Install your wall studs against your walls, spacing them 18 inches apart and nailing the bottoms of the studs to your 2x4-inch floor plates.
Drywall, Insulation, and wiring
If you'll need wiring or cable to run through your walls, do that now. Drill 1-inch holes through your wall studs and run your wiring through these holes. Then, place insulation between the studs, attach drywall to the studs, and cut out pieces for needed electrical, speaker, or microphone cable outlets.
Attach the last of your plywood against your ceiling, cutting holes for lighting fixtures, etc.
Soundproof Wall Panels
Attach soundproofing panels or tiles to your drywall. Usually, you can purchase these panels or tiles at hardware stores or home improvement centers.
Install doors, avoiding the use of solid doors that can transmit sound vibrations. Instead, use multi-layered doors or those with fiberglass insulation.
Carpet and Padding
Finish your booth by laying carpet padding and thick carpet that will absorb sound.