Soundproofing and Acoustical Treatment By Dan Lenard – The Home Studio Master and President of World Voices Organization
Here’s some confusing terminology about home voice over studios.- What’s the difference between Soundproofing and Acoustical treatment? I get a lot of emails from people who still don’t get this. With a home voice over studio, from an acoustic perspective, you have two big challenges.
Keeping outside noise out and keeping the noise you make reading all those commercials and audiobooks from bouncing all over the room and back to your mic.
Differences Between Soundproofing and Acoustical Treatments
Let’s start with the more challenging and more expensive “sound Proofing.”
The term ‘soundproofing’ is somewhat misleading because, truth be told, especially with a home voice over studio, you can cut down on sound leakage, but without expensive and specific building techniques, you can’t get rid of it altogether. Soundproofing is specifically designed to increase the degree of acoustic isolation between the studio and the world outside — cutting down on noise that leaks into or out of the studio. Sound isolation works the same both ways, so there’s no difference in approach to keeping sound in or out.
So let’s change some terminology about you at home. We will start using the term “Sound isolation” instead of sound-proofing. That means finding a place to record farthest from outside noises and the noise caused by the mechanicals in your house. That’s why interior closets if they’re big enough, make the most sense. If you have no walk-in closets, you may have to improvise. The best way (and most expensive) to block sound is to put a solid wall in its way — the more solid, the better the isolation you’ll get. As a rule, if you double the mass of a wall, you halve the amount of sound transmitted through it. But you must be surrounded on six sides (Walls, ceiling and the floor) in a square room. And that includes the proper type of door that can seal you in. You can build a booth, which is not easy or buy a prefab isolation booth. Also not cheap. There’s a lot more to complete soundproofing, which is a topic for professionals who understand how to construct these booths.
Acoustic treatment, on the other hand, in the context of a recording studio, generally deals with the acoustic quality of the room from a listener’s point of view. In other words, Do you hear an echo of your voice from the walls? Does it sound “muddy” or like you’re under a shelf or in a tube? You prevent this by using what we call Acoustic Diffusion and Acoustical Absorption.
Here’s a question I get too many times. Do egg crates soundproof a room?
Egg boxes can make a marginal improvement to some aspects of a room’s acoustics by breaking up those reflections from hard surfaces, but they are virtually useless for soundproofing. The same is true of lightweight suspended ceilings, acoustic foam and acoustical blankets. All these materials have their uses, but they’re mainly for acoustic treatment, not for soundproofing.
So, there is no such thing as “Sound Proofing Foam.” Acoustical foam is transparent to sound. It goes right through.
Again the best acoustic environment is a closet full of clothes! You can close the door behind you, and clothes Diffuse and absorb sound Like nothing else.
Also, with voice over, it’s important to understand that the louder you talk, the more any acoustical imperfections in your recording space will reveal themselves in your recording. The same holds true for the quality of the microphone you use. More sensitive mics will pick up everything, from faint exterior noise to your voice being reflected into a corner and back to the mic.