How does Acoustic Foam Work?

If you have a recording studio or home theater, then you know all about dealing with unwanted sounds.

Hard surfaces in your studio or theater provide a surface for sound waves to reflect and bounce off of creating echoes and reverberations which can ruin the audio quality.

Instead of renting out a professional studio or applying an expensive fix like redoing the wall, etc, you can try installing some acoustic foam. 

You may be wondering “what is acoustic foam?” and “how does acoustic foam work?”

Well, in this article, you will find the answers to these questions and more so keep reading to improve audio quality in your home studio or theater. 

What is acoustic foam?

Acoustic foam is best used to absorb airborne sound waves to reduce echoes and reverb to improve sound quality.

They can be made from several types of foam including melamine foam, polyester or polyether foam.

You can also find various types of acoustic foam as you will read later on as you dive deeper into this article.

Acoustic foam can be placed on walls, ceilings, doors, and any other surface that you think sound bounces off of. 

They can be treated with dyes and come in different shapes and sizes with some even being fire-retardant. 

How does acoustic foam work?

acoustic soundproofing foam on wall

Before diving into the way acoustic foam works you will need to have a basic understanding of the way sound works. 

When a sound is created, it causes vibrations in the air known as soundwaves.

These soundwaves move along through the air until the air inside of your ears starts to vibrate and your brain interprets the sound as either noise, speech or music. 

Soundwaves also interact with surfaces and can do so in many ways. 

The way sound waves interact with a surface will depend on the type of surface that it is dealing with. 

There are basically four different ways in which a sound wave can interact with a surface. 

These include penetration, absorption, reflection and diffusion. 

Penetration occurs when a full sound wave or part of a sound wave travels through the entire surface while absorption is when all or part of the sound wave is absorbed by the surface. 

Reflection is when the sound wave ricochets off a surface and sends it in another direction. 

Diffusion is when a sound wave breaks apart on an irregular-shaped surface and small portions of the soundwaves go outwards in various directions. 

This can cause all sorts of trouble when recording music or watching a movie since there will be a lot more echo, flutter and reverb than you would want. 

No matter how hard you try with your sound settings it will be very hard to eliminate all the reverbs from the bouncing sound waves and this is where acoustic foam comes in.

So what does acoustic foam do?

Acoustic foam absorbs sound waves so that the waves are cut short and are unable to reflect. 

They also cover up hard surfaces which prevent sound waves from bouncing around the room.

When the acoustic foam absorbs these soundwaves, the energy dissipates as heat and the end result is cleaner and crisper audio.

Types of acoustic soundproofing foam

Aside from colors and materials, acoustic soundproofing foam comes in a variety of shapes.

The shape of the acoustic foam can help to improve its absorbing properties.

Grid foam

You can opt to use grid foam if you are interested in having a simple yet aesthetically pleasing look in your recording studio. 

This is because grid foam is more subtly shaped when compared to the other options. 

It can be organized in a grid pattern or by interlocking squares to give you a clean and professional look 

Spade foam

Spade foam is similar to grid foam in the way they work to absorb sounds. 

However, this type of foam looks like the spades in a set of playing cards except it has more of a 3D effect. 

The slightly raised angle of the rows and rows of speed helps improve their sound-absorbing capabilities. 

This allows it to enhance sound quality a little more than grid acoustic foam which has a smoother texture. 

Pyramid foam

Pyramid acoustic foam is cut into 3D pyramids which gives it greater sound absorption qualities than grid or spade form. 

The only downside to pyramid foam is that it may not absorb as many sound frequencies as the other acoustic foams. 

However, this can be rectified if you use corner block observers in conjunction with your pyramid foam. 

Eggcrate foam

Egg crate foam is one of the most affordable acoustic foam on the market. 

This makes it one of the most common in almost every home theater or studio. 

However, eggcrate foam like pyramid foam does not absorb as many sound frequencies as you may want. 

If you do opt to go with eggcrate foam, pair it with an acoustic cloth or a similar product to achieve superior sound absorption at an affordable price. 

Wedge foam

Wedge foam is the most preferred type of acoustic foam since it offers amazing sound-absorbing properties due to its spiky and pointed ends. 

Keep in mind that the bigger the wedge, the better the sound absorption. 

However, if you are looking to control found in large spaces wedge foam may not be the best option. 

Smooth foam

Smooth foam as the name suggests has very little if any texture at all. 

This type of acoustic foam does not absorb sound very well and in some cases, it may even reflect sound more thus increasing the problem. 

You can still choose to use smooth foam panels but you may not want to cover your entire home studio with this type of acoustic foam. 

Does soundproof foam work?

The short answer is yes but this is where the lines get blurred a little since most people associate the word soundproof with sound blocking.

Acoustic soundproof foam absorbs sounds rather than blocking out sounds.

To have a better understanding, let’s take a look at sound blocking vs sound absorption.

Sound blocking

Sound blocking is the process of blocking noise from entering or exiting a room. 

This can be achieved through various methods and can block out a range of sounds. 

You can choose to be soundproof if you wish to block out your noisy neighbors or if you’re building a soundproof theater. 

To block sounds, you will need to target the vibrations in the air after a sound is created.

You can do this by adding mass to a wall or creating dead air between two separate walls. 

This will stop the vibrations which will stop the sound wave dead in its track and prevent it from traveling through the surface to you. 

The materials used in sound blocking won’t make the sound waves disappear altogether but they will block them from entering or exiting a space. 

You can choose to use heavy dense mass like a brick or concrete wall if your home is still being built and If your house is already built then something like mass-loaded vinyl would be better.

This is because MLV has no elastic properties so the sound waves can’t even bounce off of the material, they just stop. 

You can read more in this how to soundproof a room post.

Sound absorption

Sound absorption, on the other hand, is the process where the sound waves are absorbed instead of being blocked. 

This process reduces or eliminates flutter, echoes, reverberations and the amplification of sounds. 

In other words, sound absorption can improve the sound quality within a space. 

Unlike song blockers that are hard and dense, sound absorbers tend to be light and airy. 

While it may not sound very useful, it actually is when it comes to improving audio quality since one of the biggest problems in any space is echo and reverberation of sounds. 

As waves reverberate, they amplify which means they become louder and more annoying. 

A room filled with hard surfaces will allow soundwaves to echo by bouncing off the hard floor, wall or ceiling which will create quite a ruckus. 

Sound absorbers are designed to break up this surface which makes it harder for some waves to bounce off of. 

They usually have an open cell structure which means that they have tiny little holes in them 

This allows the sound waves in but makes it hard for them to get out again. 

The sound waves get trapped inside the structure, get absorbed and dissipate as heat. 

Sound absorbers come in different shapes which help to make it harder for soundwaves to reflect and bounce around. 

Where to install noise absorbing foam

noise absorbing foam above mixer

Acoustic noise absorbing foam comes in precut panels or sheets that you can cut yourself. 

If you are wondering which surface is the place where the acoustic foam is, then it all depends on the layout of your studio or theater. 

Let’s say you have a sound mixer at a desk in your recording studio, then some acoustic foam on the wall behind the mixer can make the world of difference. 

You may only need to use a few panels depending on the size of your wall. 

Next, you will want to look at the positioning of the acoustic form.

If you are not covering your entire wall with acoustic foam then you want to place the panels in the middle of that wall. 

You should place the acoustic foam panels at the same level as your ears so that it’s higher on the wall rather than lower. 

Aside from installing the foam behind your mixer, you can also place it on the wall directly across from the speakers. 

This will stop any sound from getting to the mixture and ruining the quality of the recording. 

Once again you may need to use a few panels. 

How to install sound isolation foam

Now that do you know what acoustic is, how it works and where to place them, you may be wondering how to install them. 

Installing these sound isolation foam panels is pretty easy using various techniques. 

The preferred choice will depend on the surface on which the panels are going to be installed and how much of an improvement in sound quality you hope to achieve. 

If installed correctly, your acoustic foam panels will give you the desired results so pay close attention to the various techniques we’ll discuss below. 

When dealing with drywall or walls with smooth surfaces you can use a spray adhesive or double-sided tape and squares. 

Concrete surfaces and textured surfaces, on the other hand, require something stronger like construction adhesive. 

So the first thing to do is to figure out your wall type before you choose the product that will be used to hang your acoustic foam. 

You will also find that some acoustic foam panels come with a sticky adhesive side which means that you won’t have to purchase another product to mount it.

The next step is cleaning the wall. 

Take a clean rag or cloth and saturate with rubbing alcohol. 

The rubbing alcohol will remove any dirt or debris from the walls so that your acoustic foam will stick better. 

Do not use any regular household cleaners since it may reduce the adhesive properties of the foam panel itself or the adhesive product you plan to use. 

Now measure the phone final on the wall that they’ll be placed on. 

Lay the panels side by side on a flat surface and use a tape measure to record their length and width. 

Take those same measurements and mark out the area on the wall where you are going to install them to give you an idea of how much space they’ll take up. 

In some instances, you may only need one panel and other times, you may need a few. 

You may also need to cut the foam panels if they do not fit. 

If that is the case, use an electric carving knife to do so since it produces a clean cut that won’t leave you with jagged edges that can affect the way the panel absorbs sounds. 

Once this is completed you can draw an outline of the foam panels on the wall by drawing an X in each corner of the installation site using your measurements. 

Against each corner of the installation area, line up a level and draw straight lines to create the edges for the foam panels. 

This will help you to keep the panels straight as you install them to give you a tidy and professional look. 

The final step would be to apply your adhesive product whether it’s an adhesive spray, tape or squares and secure the foam panel to the wall. 

If you’re interested in hanging your acoustic foam without damaging your wall, read our how to hang acoustic foam without damaging walls post 

Our top acoustic foam picks

mushroom wedge acoustic foam
  • NRC rating: 0.92
  • Mushroom wedge design
  • Flame retardant

Improve audio quality in your studio or home theater with the Sonic Acoustics Mushroom Studio Wedge Tiles.

These tiles feature 9 mushroom-shaped tiles to better absorb and break up sound waves.

They are available in different colors so they can match any decor and create a fun look.

No need to worry about using these panels in your home since they are environmentally friendly and flame retardant.

Use our coupon code ‘soundproof1’ to get 10% off your order!

2 inch acoustic foam
  • NRC rating: 0.92
  • 3D acoustic design
  • 2-inch thickness

Sonic Acoustics 2 inch sound foam works great for homes, studios and offices to provide moderate sound control with an NRC rating of 0.92.

These acoustic foam panels not only have sound-absorbing capabilities but are made from polyurethane foam and flame-retardant materials.

They are safe to use, easy to install and can be cut to size without affecting their sound-absorbing capabilities.

These foam panels are 2 inches thick which is the recommended thickness for optimal absorption.

Make sure to use our coupon code ‘soundproof1’ to get 10% off your order!

block tile acoustic foam
  • NRC rating: 0.92
  • 3D beveled block tile
  • Flame retardant

The Sonic Acoustic Beveled 9 block tile is the perfect acoustic foam to reduce echo and reverb in your home recording studio.

It has an NRC rating of 0.92 and is made from environmentally friendly polyurethane foam which means that it is safe to use.

These acoustic foam tiles also made up of flame retardant materials that prevent a fire from starting or spreading.

Buy now and use our coupon code ‘soundproof1’ to get 10% off your order!

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