How Thick Should Soundproof Foam Be?

So you plan to soundproof your space. This could be for gaming, streaming, a home studio, a home theater, or a practice and rehearsal room. No matter what, there are considerations you will need to take in determining which thickness of foam you need. Let’s discuss.

Depending on your sound requirements you may need different thicknesses of soundproofing foam. 1-inch and 2-inch foam are best for echoes, mid and high frequencies. 3-inch and 4-inch foam are best for low-end bass (bass traps). Consider that you will need a combination of all depending.

We detail in this article everything there is to know about the different types and sizes of soundproofing foam there is and describe which will best suit your situation, different frequencies, and your space.

How thick should soundproof foam be?

Depending on your situation and most probably your budget, you do not specifically have to pick one thickness for soundproof foam. Varying thicknesses will give you different audio dampening qualities. In some cases, you will even want to mix and match the thickness of the foam for different sections of the room you are trying to soundproof.

For example, you may want thick pieces of foam in the corners of the room because they absorb bass pretty well (as we will discuss). Then perhaps for the walls located in the direction of your speakers (or monitors), you would use thinner foam that better deals with mid and high frequencies.

While thick foam provides the most dampening, it is not necessarily the thickness you would always want to choose or to place around your entire room no matter the purpose (home theatres, rehearsal, band practice rooms, home recording studios, gaming, or streaming rooms).

Let’s discuss the varying thicknesses of soundproof foam and what they are optimal at dampening.

What thickness of soundproof foam can you get?

Typically there are four thicknesses of soundproof foam that you are able to purchase, and they are all measured inches (luckily). The smallest size soundproof foam you get is 1-inch, while the largest is 4-inch. As you would have guessed, 2-inch and 3-inch are in between these two.

Take into consideration that the varying levels of thickness will help dampen and absorb different frequencies better than others, and that is what we will discuss now.

Take into consideration that choosing foam will mean you are attempting your own DIY setup. Sound is sometimes an untamable monster, so it’s best to work out the acoustic situation of your room before you just going to place foam everywhere. Remember that you can also consider sound diffusers.

1-inch soundproof foam

1-inch foam is undoubtedly going to be the cheapest out of all the thicknesses of foam you can get. This will be obvious because, in essence, there is less of it. However, the quality of 1-inch foam is still surprisingly good. They off a lot in the way of reducing flutter echoes as well as controlling the high and mid-frequency ranges.

When you are looking for some control, but nothing that is overbearing and your budget is tight, there is no problem with getting yourself 1-inch foam soundproofing panels. They will do a good job. Just consider that bass absorption (damping) is minimal.

Check out this 1-inch soundproofing foam on Amazon below.

2-inch soundproof foam

2-inch soundproofing foam seems to be the most popular amongst DIY enthusiasts and commercial users alike. This soundproofing foam offers more sound absorption than the 1-inch (as you would think), and enough dampening of the mid and high frequencies to ensure that this type of foam is used in vocal booths, broadcasting, home theaters, home studios, and rehearsal spaces.

Check out this 2-inch soundproofing foam on Amazon below.

3-inch soundproof foam

2-inch soundproofing foam is where we start to see bass dampening. Not only will there be bass dampening with the 3-inch foam, but there will be good absorption of the high and mid frequencies as well.

The one thing you will need to consider (even if you have the money) is that if you plaster your space with 3-inch foam, you will significantly reduce the room size. Even if you don’t think so, the reduction in space will be 6-inches. Remember that you will be putting them on all the walls.

If you consider this and work out the complete volume that 3-inch volume will take up in your space, it equates to 216 inches. That is how much soundproofing foam 3-inches will take up if you cover all the walls and ceiling.

Therefore, we only recommend using 3-inch foam as a bass trap and inserting them into the corners of your space.

Check out this 3-inch bass trap foam on Amazon below.

4-inch soundproof foam

If you are Looking at the 4-inch foam, you are in a space where the bass is reflected everywhere, there is boom feedback, and the sound is just an incomprehensible mess (low-end problems). You would think that 4-inch foam (because it is the thickest) would be the best at absorbing all frequencies.

However, it is actually only good for absorbing a lot of low-end. Again we only recommend using this thickness of foam for bass traps and in the corners of your space. If you are having a problem with rumbling, shaking, and just overall bass problems, this is your answer.

Check out this 4-inch bass trap foam on Amazon below.

How much soundproof foam do I need?

This will vary depending on the type of audio passed throughout your space. You will have to consider that a podcast space will not require as much foam as that of a home theater.

You will need between 20% and 30% coverage depending on echoes and reflections in your space. This will also be affected by the type of walls you have. Remember that concrete will reflect while drywall (sheetrock) and wood will have some absorption attributes.

DIY Soundproof Walls for a Home Rec...
DIY Soundproof Walls for a Home Recording Studio

This will apply to all spaces, including broadcasting, home studios, gaming, streaming, etc. In cases where you have lots of bass, remember that you will more likely need a bass trap rather than lots of pieces of foam on the walls.

When you find the mids and highs to be too much, your space coverage may go up to 50% depending on how severe the problem is.

If you are looking to create a vocal booth, you will want complete isolation, but this is not necessarily done just with foam.

Does the shape of soundproof foam matter?

If you consider that sound diffusers are built with different shapes to reduce echoes and reflections, you can assume that other shapes of soundproofing foam will do the same, and you would be correct.

The different shapes of space will be prevalent correctly choosing what type of foam you need, so be aware of that. The best thing you can do is to use different types of foam in your space where applicable and not just one type or shape.

It seems complicated, but you will have to consider doing a lot of testing to get this right.

Conclusion

We discovered that depending on your requirements, the shape of your space, and how the sound reflects and echoes in it would determine what type of soundproofing foam you need. There are varying sizes in soundproof foam. The thinner sizes (1 and 2-inch) cater more for echoes, mid, and high frequencies, while the thicker foams (3 and 4-inches) are more for bass.

Consider that you will need to test your sound to determine which foam suits your situation best.

Devlon Jarrod Horne

I am passionate about everything I undertake with music being my first love! I started playing guitar and singing at the age of 13 and have toured extensively throughout the UK, SA, and the UAE, playing and recording in original bands, cover bands, theatres, shows, and productions. I graduated top of my class at Damelin College of Music in South Africa and have his graded classical theory and composition from the Royal Schools Of Music in London. I have taught privately, for schools, companies, and online since 2006, and have founded Master Music Talent Academy where I employ and share my love of music with some of the top pro players, performers, and teachers in the South African music industry.

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