Acoustic Treatment for Your Booth
Professional vocal recordings are no longer limited to commercial production studios. High-quality voice-overs are now recorded and produced in small studios and private home studios. One of the key factors in how professional voice talents achieve quality vocal recordings in their home studios is the proper treatment of their vocal booth.
Soundproofing vs. Acoustic Treatment
Many people refer to noise absorption and diffusion within a room or space as soundproofing; however, carpets and acoustic foam can only dampen noise and not completely block it. The process of soundproofing starts with constructing your room or booth using very dense materials, such as thick plaster instead of drywall. When soundproofing is not an option, treating the room’s acoustics can help you overcome this setback.
Room Selection
Choose a room that is remote and preferably without a window. This can be a corner of your room, even a closet or storage space, as long as it provides ample lighting, access to electricity, and ventilation.
Also, evaluate the amount of ambient noise and acoustics you are experiencing and the source of the noise, as you will need to decide how to dampen it using heavy curtains, carpets on the floor, and wall coverings.
Acoustic Treatment and Sound Capture
Ideally, you will want to build a “room within a room” where the booth walls are separate from the actual room. Isolation can be improved by increasing mass. Since sound is energy, the more mass you have, the more energy is required for sound to pass through and vibrate.
The minimum treatment for a room is 20% of five surfaces: this means that 20% of the four walls and the ceiling should be covered.
The size and quality of the acoustic material will affect room reflections. The following table shows the standing waves produced based on room size:
Room Dimension – Resonance Frequency
- 8 feet – 141 Hz
- 7 feet – 161 Hz
- 6 feet – 188 Hz
- 5 feet – 226 Hz
- 4 feet – 283 Hz
- 3 feet – 377 Hz
Selecting an absorbent material that works within this range will help absorb the lower midrange frequencies that a typical voice produces.
Some sound panels can absorb vocal energy down to 200 Hz, while other foam materials only absorb above 500 Hz, resulting in a boxy tone or excessive bass. A better room treatment involves using a combination of foam and acoustic panels, employing a mixture of absorption or diffusion solutions.
Room treatment can be highly technical and, depending on the room size, may require an investment. Since every room is unique, consulting an expert may be necessary to determine the proper treatment for your vocal booth. However, you can start with the basics, and as you use the vocal booth more, you will understand the true sound of the room and how it affects your recording quality.
