With professional studio equipment becoming more available and the growing popularity of do-it-yourself YouTube channels as a means of income, understanding acoustics and sound management is more necessary than ever. If you’ve heard the difference between a band recorded in a garage compared to a band recorded in a studio, there is no question about it. The proper management of acoustics is paramount when it comes to audio recording. There are a range of things you can do to control the acoustics in your space and this guide should help you understand the physics of sound and what you can do to manage it.
Sound proofing a home studio
Understanding acoustics and how they operate is extremely important in order to create a room or home studio where your acoustics are under control. The definition of acoustics is “the properties or qualities of a room or building that determine how sound is transmitted in it.” Many colleges offer degrees in acoustic engineering for people who plan on designing or managing spaces where sound will be a primary concern like concert halls or opera houses. Acoustics primarily focus on how sound waves travel throughout a space with specific regard for where sound is coming from, how it bounces off surfaces, and how it reaches its audience in different areas. To imagine what sound waves look like, a very good comparison is like dropping a rock into a perfectly still pond.
Sound waves travel away from their source the way waves travel in a circular pattern away from where the rock hit the water. The only difference is that sound is directional, so you could cut one portion of the circle like a slice of pizza and analyze it just like that. When thinking directionally, sound waves look like small semi-circles. When they reach a surface like a wall they will bounce and continue to travel in another direction the same way a ball on a pool table ricochet off a wall. Unlike water, sound waves can travel across one another without effecting each other. The composition of the surface can have a very large impact on how the sound bounces off the surface. A porous surface like sound foam will absorb the majority of the sound waves and only allow a minimal amount to bounce, while a hard surface like drywall or a garage door will absorb almost none of the sound and send the sound waves in other directions with almost no loss in energy.
Now imagine you’re looking at the waves from the side, like you’re eyes are directly at the surface of the water. Sound waves travel from side to side with an up and down motion. The distance between the water when it was perfectly still, and the height of the wave is the amplitude of the sound wave, or the volume. As that sound hits a porous surface, most of its energy will be absorbed and a very small wave will travel against the source. When a sound wave hits a hard surface, you’ll see a new wave with almost equal amplitude traveling in the opposite direction from the surface.
If you can think of a time when you’ve been in a space with a very pronounced echo the surfaces of the walls have probably been very hard, like a cave or an empty warehouse. Studios and sound proofed rooms have sound absorbing materials on the walls and have no echo whatsoever. Take a moment while you’re reading this and snap your fingers. Notice that at the tail end of what you hear, the snap sounds like it’s coming from the furthest point away from you in whatever room you’re in, unless you’ve already sound proofed your room, then why are you reading this??
There are some do-it-yourself solutions to control sound in your room, but the professionally engineered sound proofing products you can buy are usually worth the money. My first experience with sound proofing came when I was a high schooler. I was fortunate enough to have neighbors that did not mind hearing my drums until one of our neighbors sold their house and the person that moved in was not as nice. He called the police every time he heard me drumming and brought the issue up with our home owners association. After reviewing the situation, they asked my family to make some effort to sound proof the room that my drums were in.
Sound proofing is actually about air. Sound needs air to travel through and surfaces simply create more opportunities for vibration to occur. If you think about any concert hall or movie theater you’ve been too, you usually have to walk through a hallway to get from the lobby to the actual theater. The space between the wall of the theater and the wall of the lobby is where most of the sound proofing occurs. Sound proofing foam, sometimes referred to as egg-crates due to their unique shape, has thousands of tiny pockets of air with very thin surfaces. These pockets of air capture and redirect the sound until it lacks sufficient energy to pass through the other side.
Woven fabrics are also great for sound proofing, but it’s not as simple as putting a blanket up on the wall. Putting a comforter up on the wall will go a long way to control and capture sound, but there are smarter ways to do it. We soundproofed our drum room with three steps. The first thing we did is we covered the inside of that rooms only exterior wall with a very cheap type of wood called chipboard. Chipboard is essentially wood chips compressed into a flat sheet. We cut enough chipboard to completely cover the wall. The cost of the chipboard was less than $90. The second thing we did was staple to the chipboard enough sound proof foam to cover it completely. Egg crate foam can actually be bought at a fair price if you buy the sheets designed for mattress pads. They’re not as pretty as the smaller sheets that are marketed specifically for sound, and when you line them up side by side the pattern will not line up so if you are even a little OCD about design, you might want to buy the expensive stuff. Whether you buy the bed stuff or the sound stuff, it will work exactly the same. Our last step was the most expensive; we replaced our single pane window with a double-paned window. Again, the air between the two sheets of glass did a lot to dissipate the sound waves. This was more than a decade ago, so chances are your room might already have double-paned windows.
Recommended sound proof materials
Here are some recommendations for the materials described above:
Egg Crate Foam
This is enough foam for full sized mattress, but you can order different sizes for different prices. You can cut it with scissors to match your walls dimensions. The more coverage, the dryer the sound.
Sound Proof Foam
This is the same material as the egg crate foam, but marketed for sound proofing. It will do the exact same thing but it will look much more professional on your wall. This specific product comes with 6 12”x12” pads.
For chipboard you will want to go to your local hardware store as you can’t order the thicker sheets online.
One highly effective do-it-yourself solution involves a little wood, a towel, and some old t-shirts. Go to the hardware store and get the longest piece of wood you can find that is about 2” x 2”. You’ll want to cut the wood so that you can make a few rectangular frames that are about 18” wide and 36” tall. Make as many of these frames that the wood will allow.
Simply staple a towel around the edges of the frame like upholstery, turn it over and stuff the inside of the frame with rolled up old t-shirts, then you can upholster a towel to the reverse side and hang it on your wall. Congratulations, you’ve just created a sound proof pad. Just one or two of these will go a long way towards controlling the echo in your room, so if you’re only looking to manage your acoustics so that your YouTube videos sound a bit more professional, this will work just fine. For studio applications, you may want to consider purchasing some real soundproofing.
High end room sound proofing
Professional Sound Panels
This is about as good as it gets. If you walk into any studio, movie theater, or concert hall you’ll notice that the entire wall is made up of this material. This is what the professionals use. You can buy as many of these as you’d like and cover your room with them. It will not only keep the acoustics in the room under control, but it will also help to reduce the volume that leaves the room, especially if you can create complete coverage on the walls you’re most concerned with. These are the going to be the toughest panels to work with because they can’t be adjusted. When you get to the part of your wall that has electric outlets or light switches, it will be very difficult to find a way to mount these in a way that is not obstructive.
We hope this guide helps you manage your acoustics!