03. What is Soundproofing? Basics
When you think of soundproofing, the image of a “soundproof room” likely comes to mind. Soundproof rooms are used to block outside noise from entering or prevent inside sounds from escaping, much like wearing headphones.
Soundproofing refers to “controlling sound to suit a specific purpose.” There are two main aspects of sound control: managing the “direction and destination” of sound and controlling “sound energy.”
Generally, sound direction and destination are controlled by sound insulation, while sound energy is managed with sound absorption. So, in simple terms, soundproofing = sound insulation + sound absorption. A common misunderstanding is to think of sound insulation as the same as sound absorption or even to equate sound absorption with soundproofing. To clarify: sound insulation reflects sound, while sound absorption does not. Think of them as opposites, like the positive and negative ends of a battery.
Sound Insulation Only
Sound insulation reflects sound. Reflected sound doesn’t “disappear” but instead bounces off other surfaces, creating an echo or reverberation. With insulation alone, spaces become echoey like a bathroom, and sound can even end up louder than the original noise. Thus, without sound absorption, insulated spaces may still allow more sound to escape.
Sound Absorption Only
Sound absorption doesn’t reflect sound, but this means that absorption materials alone provide minimal insulation since sound can easily pass through. With only sound absorption, insulation is weak, allowing sound to leak out.
This is why effective soundproofing requires both sound insulation and sound absorption, as illustrated below.
Soundproofing Techniques
By using sound-insulating materials to create barriers, we control the direction and destination of sound, while sound absorption manages the energy of the sound. This is why concert halls have unique shapes—they’re designed to control how sound reflects, reaches the audience, and decays.
Simply building a square soundproof room, however, won’t guarantee effective soundproofing. Other factors to consider include how sound travels within the room, acoustic issues (like flutter echoes and booming), vibration control, ventilation, windows, transmission loss, and reverberation time. Yes, it’s complicated, and getting the knowledge you need requires some study.
You might need to read a thick book like this…
However, even a book won’t solve every issue. Many soundproofing companies have made mistakes despite their experience. Mistakes teach valuable lessons, and experience is essential. I’m not saying that studying isn’t important, but it’s not enough by itself.
Just like a popular ramen chef didn’t make the perfect bowl from day one—it took years of trial, research, and practice. Soundproofing is similar; it’s an art that takes expertise and can’t be easily replicated.
Summary:
DIY Soundproofing Recommendations
For those who aren’t familiar with soundproofing, where should you start? That’s where I come in! As a soundproofing enthusiast, I want to spread awareness about soundproofing techniques since there’s so much to learn. Feel free to ask questions!