Forget everything you’ve learned over the internet and what your friends keep telling you. There are no magic beans you’ll buy to stop sound from going out or noise from entering your home recording studio. Soundproofing is the only way to affect the amount of sound or noise that can travel through your home studio. There is no 100 percent soundproof room, but you can work on minimizing the volume and frequency.
Soundproofing should not be confused with acoustic treatment. Acoustic treatment is done to improve how your recording room will sound. In contrast, soundproofing is done to block or reduce the volume and frequency of sound going into or out of a recording studio.
Methods of Soundproofing
There are three main methods of improving the soundproofing properties of your studio recording. These are adding mass, achieving an airtight construction, and decoupling structures. Let’s look at each of these in more detail below.
This is the simplest method of soundproofing a room. Every addition in mass will improve the home studio’s isolation by about 6dB. This is known as the Mass Law. Although it applies to nonrigid assemblies, you can use it to approximate the possible isolation. Adding mass is especially effective for higher frequencies. Soundproofing for lower frequencies by adding mass is much more challenging to achieve.
When adding materials choose denser as opposed to thicker. Denser materials have more mass, hence do not vibrate as much. Particle board will be better than plywood, which will be better than drywall, which is better than acoustic foam for soundproofing. The STC ratings (Sound Transmission Class) can help you decide on the materials. The higher the STC rating, the better the isolation value. However, remember that STC ratings are designed for audio frequencies dealing with human speech, not music.
Simply put, where air goes, sound goes.
Sound transmission through small cracks and openings should always be considered. Even if you install and test different sound isolation materials, the isolation will be less when the job is finished, and there are air paths. Small cracks and gaps can exist at the bottom of the walls, around windows, and under doors. Other commonly ignored areas to check are around electrical boxes, corners of the room where wallboards meet, and the physical joints between the wallboards.
Most of these areas are ignored, so you’ll go through a lot of hard construction work and still achieve nothing. Small cracks and gaps around walls, windows, and electrical installations can be filled with acoustic caulk/sealant. Adding a bottom seal with a threshold for larger gaps like under the door will help minimize sound escaping or noise going in.
Decoupling means isolating your room and recording equipment from the rest of the building. Sound travels through the structure of the building by following what are called flanking paths. A good example is placing your ear on a wooden stud, and someone taps it with a hammer on the other end. You’ll hear the sound through the stud more clearly, than listening to the same tap in a room.
Sound transmission will travel through the building structure very well, so disconnecting your recording studio from the rest of the building is important. Apart from traveling through the structure of the building, other sources of flanking sounds include water pipes, HVAC systems ductwork, and drainage and sewer pipes. Anything that connects different parts of the building with your home recording studio is a potential pathway for sound to travel.
If you’re building a recording studio, you can take these into the structure’s design. However, if your current studio is within a building, you can work on isolating your room from the existing structure. You can decouple your room by using resilient channels on walls and ceilings, installing a floating floor with a soundproofing underlayment, or using isolation pads on your studio gear to absorb vibrations.
Steps to Soundproof a Home Recording Studio
Step 1 – Work on the Wall
Existing walls are going to be one of the biggest challenges to soundproofing. They are a long way from being airtight; sometimes, adding extra materials is impossible. If you’re using a basement, you’ll have to contend with windows, or if you’re set up camp in your bedroom, you might not be allowed to make changes. All these situations have solutions that you can use to improve the soundproof qualities of the space.
First, you can start with a simple thing as filling cracks and gaps around the room, which will go a long way in stopping sound. Adding mass to the walls can also help, but the ultimate method is to isolate the walls in your room from the rest of the building.
Resilient channels (RC) and RISC (resilient sound isolation clips) assemblies are two ways of isolating the walls. Remove the existing layer and add resilient channels on the inside part of the wall. This effectively decouples the inside and outside walls and the rest of the building. RISC 1 clips are another way of decoupling drywall from a structure using a rubber isolator.
Apart from resilient channels and RISC assemblies, you can also use staggered stud configuration in the existing walls. Staggering studs from one another on opposite sides decouple the drywall surfaces and also reduce the need for RC and RISC systems. However, the top and bottom plates can act as a bridge of sound from one side to the other. Truly isolating the top and bottom plates effectively decouples the two walls.
Step 2 – Doors and Windows
Doors and windows are other areas to fix when soundproofing. While it is possible sometimes to get rid of the window, a door is a must to enter and leave the room. Between doors and windows, the latter is the easiest to soundproof.
Soundproofing existing windows can be as simple as adding mass to them. This involves everything from adding very heavy drapes to replacing the glass panes with thicker options. Building a window plug is also simple and very effective at soundproofing. The window plug is temporary and can be removed and installed as needed. Apart from these, use acoustic caulk to fill up cracks around the window.
Unlike a window, doors are built with the intent that the seal is going to be continually violated. The problem is you cannot permanently fix the gaps in a door because they are required to operate properly. One way to improve the door is to use a solid core door. Solid core doors are heavier and block out more sound than hollow core doors. A solid core door can be improved by adding mass to the inner face. An 8psf sheet of lead sandwiched between the door and a piece of 3/4-inch plywood goes a long way to stop sound.
A bottom seal with a threshold should also be added to stop sound transmission at the bottom gap of the door. The TMS Automatic Door Bottom with Neoprene Bulb Seal is a great way to go in blocking sound transmission without interfering with how the door works.
Step 3 – Ceiling and Floors
One man’s ceiling is another man’s floor.
While you’re trying to make some good music, another person wants to quietly read a book, sleep, or settle a baby down. In your quest to soundproof your home recording studio, the whole system will be as good as the weakest link. The space above and below you offer one of the greatest challenges.
When working to soundproof a ceiling or floor, you should keep your eye first on adding more mass. If you’re looking to soundproof your ceiling, add a floating floor on the room above to prevent the transfer of sound through the joists. The best underlayment for soundproofing is rubber or cork. The ceiling can also be decoupled from the floor above to prevent sound transmission.
Resilient channels will work on ceilings as they do on walls. RISC-1 clips and hat sections can also be used on ceilings and give the same results on walls. However, the disadvantage of using this system on ceilings is that you might not have airtight gaps around the perimeter. You can also add dampening materials to the ceiling to absorb sound. These include materials like sheet-loaded vinyl and polymeric materials using mineral fillers.
To soundproof a floor, the simplest solution would be to install a floating floor with a sound-absorbing underlayment. Rubber and cork offer the best noise isolation properties and are the best to use. Floating floors are decoupled from the whole building, and the good news is you can install a floating floor over your existing floor.
Step 4 – Electronic Noise
Once you’ve wired everything right, but you get a buzzing sound from your monitors and other sound systems, what could be the problem?
Most noise issues in a home recording studio can be traced to ground loops. Ground loops form if the ground of different units connects through chassis, rack rails, or the third prong of the ground on the power cable. To eliminate ground loops, I recommend using isolation transformers. An electrical transformer allows desired signals to pass freely without interrupting ground continuity, thus breaking ground loops.
White noise and electrical hums from spinning fans in our computers and other electronics can also affect our recordings. To avoid this noise, record your tracks as far away from the computer and other electronics as possible. If not possible, use dynamic microphones because they will pick up less ambient noise in the room. An isolating box, or iso box, is also another solution to keep your equipment cool while reducing the amount of noise they generate.
Another source of electrical noise can be your lighting. Avoid the use of fluorescent lighting because the ballasts can be very noisy. You should also avoid simple switchable dimmer systems; if you must use them, stick to good quality professional systems. LED lights are the best lighting source for your studio because they produce no sound and give out very little heat. They are also dimmable and color-changing using modern programmable control systems.