Sound vibrations are transmitted through the air, causing problems with noise entering and exiting your home studio or any space. Many materials used in home construction, such as wood and drywall and glass are conductors of sound. Blocking out these sound waves is the purpose of a soundproof room. This is usually done for a home music studio.
For the highest quality, most complete soundproofing, you should hire a professional. The cost of a professional can be prohibitive for many people. You can construct a soundproof room in your home with a little knowledge and the right soundproofing material.
How Soundproofing Material Works
Soundproofing material works by interrupting sound vibrations. This isolation must be complete (wall to wall or the entire ceiling), or you are wasting your time. One hole in the material will ruin the effect and allow the sound through even a hole as small as 1% of the surface area you are trying to treat. Sound waves can travel through the smallest hole or gap in the material.
Fiberglass or glass wool is the material preferred by many professionals because it comes in a variety of densities. The higher the density, the better the performance in stopping sound. The sound wave enters the glass wool and due to the friction between the sound wave and the wool the energy gets converted into heat, thus slowing the wave down. Lead barriers are often used in professional studios as this stops the wave completely. These need to be installed by someone knowledgeable in both the material and the principles of sound waves. This understanding makes the professional the best choice if you want the job done as thoroughly as possible.
Sound Absorbing Panels – Are not to be confused with Soundproofing!
Sound absorbing and soundproofing materials work differently. Each product has different purposes and the two are not interchangeable.
Acoustic foam is sometimes used by professionals and often used by the do it yourself person. This is not used for soundproofing, but for absorbing the sounds within the studio to treat reverberation. Not all foam is created equal and these materials are rated for fire safety. The ratings are listed as class A, B, or C. Fatal fires have resulted from use of inferior materials. The class A material is the most expensive, but is the most fireproof. Your safety is worth the additional expense.
A more expensive option, but safer and more visually appealing are fabric upholstered acoustic panels. These are boxes that have acoustic insulation in them, then wrapped in the fabric of your choice. The fabric needs to have some kind of acoustic transparency to allow the sound wave through it, but that needs to be explained in another article. These can be made much bigger and thicker than acoustic foam and are more rigid and can be used for hanging ceiling panels as well.
The purpose of soundproofing material is to reduce the sound waves being transmitted into or out of your studio. This is generally done through material in the walls, ceiling, floors and windows of the studio. Most materials are rated for the number of decibels the sound is reduced. This is measured in STC (Sound Transmission Class) or RW (Weighted Sound Reduction Index). For the materials to be effective you need to understand the noise reduction required and they must be installed correctly.
Using and Installing Soundproofing Materials
A double wall is the ideal sound barrier that can be built by the do it yourself handyman. When building a second wall, it’s important to use floor insulation. This prevents the sound waves from being transmitted between the two walls via the flooring. Flooring carries acoustical energy and once the vibrations start, it can be nearly impossible to stop them. Thick carpeting is used because it absorbs these vibrations. There is no sound when walking on thick carpet.
To be effective, don’t just nail sheets of drywall to the existing wall surface. Sound will travel through the wall to the drywall. You need to create two completely independent wall sections. Make sure the studs aren’t directly across from each other and a large enough cavity for the sound wave to slow down between the 2 walls. For best results, studs should be staggered across the length of the wall. A concrete surface at the bottom of the wall helps prevent sound from reaching the other wall and ultimately, your room.
The space in between is filled with sound proof material. Fibreglass insulating material or glass wool can be used in the cavity to increase the effectiveness of the sound separation. Be sure to leave 5-8 inches (125-200mm)of space between the two walls for absorbing the noise adequately.