egg cartons and acoustics

How Effective Is It To Soundproof A Room By Using Egg Cartons?

Egg cartons will not work in soundproofing a room. The thin material will not absorb sound. Egg cartons do have an uneven surface that can assist with handling internal room reflections similar to the principles of an acoustic diffuser, however, the benefits are very limited. It is also important to note that egg cartons are a fire risk, therefore unsuitable for business and home use. Acoustic foam is a better solution.

Where did the idea of using egg cartons to soundproof a room come from?

At some point, someone got the idea of sticking egg cartons to a wall of a studio to soundproof or acoustically treat the studio.

This became incredibly popular as in comparison to the price of acoustic foam in the past, egg cartons were very cheap.

Although I have been unable to track down the original source of the “egg carton trick”, I think it is fair to assume that some high profile producer or artist must have used it in order for it to gain the popularity status that it has.

However, with the production of cheaper acoustic foam and soundproofing solutions that are available on the market today, using egg cartons in a studio should have disappeared off the face of the planet, but using egg cartons to soundproof a room is an acoustic myth that is still hanging around. 

egg carton shape and acoustics

What’s the thinking behind using egg cartons in a studio?

Many people believe that sticking egg cartons to their studio wall will act as a soundproofing treatment. This is not true.

In order for a material to have “soundproofing properties”, it needs to be heavy and dense.

Here in the UK, egg cartons are typically made from a paper pulp material, although plastic egg cartons are becoming popular on some cheaper brands.

The original intent was to use the paper pulp egg cartons.

Paper pulp egg cartons are just too thin to form any sort of soundproofing barrier. Sound will easily travel through egg cartons as materials need to be thick and dense to absorb sound.

Egg Cartons as Diffusers

Perhaps the original studio users of egg cartons were intending to make a homemade acoustic diffuser instead?

What is an acoustic diffuser?

An acoustic diffuser is a rough or uneven surface that helps scatter sound waves throughout your room.

Acoustic diffusers are excellent for room acoustic treatment as they help to control internal room reflections.

Below is an image of some designed acoustic diffusers. It is a highly uneven surface, carefully designed to reflect sound waves and scatter them throughout your studio. 

This image is just one example, but there are many different products on the market, ranging from “affordable” to very expensive.

difusser for acoustic

Using diffusers have the benefit of controlling and handling unwanted studio room sound issues such as internal room reflections, echos/reverb and standing waves. 

These unwanted room acoustics could be making you hear sound on a recording that isn’t truly there.

For example, imagine you are mixing an audio track and it sounds really bass-heavy. As a producer, you will most likely apply EQ (equalisation) to remove the muddy bass sound. 

But, imagine that the bass sound is not actually on the recording, but is being created by a buildup of sound reflections in your room? Your studio is giving the impression that there is a lot of bass.

Once you take your mix and listen in another room, you may have found that you have removed too much bass and the audio mix now sounds too “tinny” and lacking bass. 

Therefore, it is important to control internal room acoustics when mixing so you are mixing the true recorded audio and not being influenced by “false” effects created by room acoustics. 

This is where acoustic diffusers can help as if used correctly they will scatter sound waves throughout your room, creating balanced room acoustics.

As egg cartons have a bumpy and uneven surface, I can imagine someone looking at the underside of an egg carton and thinking “that would make a good diffuser”.

In theory, as a DIY approach, egg cartons stuck on a wall would scatter sound waves throughout the room like a diffuser – any relatively hard and uneven surface would.

For example, a great homemade DIY approach to creating an acoustic diffuser is to place a full bookcase in your studio – with the books uneven to create a rough and uneven surface. 

True acoustic diffusers are carefully designed using mathematical equations so a DIY solution will never be as effective, but might be good enough for a studio owner on a budget. 

pro studio acoustic treatment

Fire Risk 🔥🔥🔥

For a studio owner on a budget, egg cartons might seem like a cost-effective solution to getting a DIY acoustic diffuser, however, from a health and safety point of view, it is a major fire risk. 

Sticking egg cartons to any wall is a major fire risk. 

A wall of egg cartons, in close proximity to a flame, will ignite in seconds and spread quickly.

Here in the UK, it is the responsibility of the business or property occupier to ensure that their property or workplace meets fire regulations. 

I am no expert, but part of the fire risk assessment is to identify sources of fuel that could help a fire spread quickly.

Here is an extract from the “Fire safety risk assessment: offices and shops”, from the UK government, for example. 

“Sources of Ignition”

“Anything that burns is fuel for a fire. You need to look for the things that will burn reasonably easily and are in enough quantity to provide fuel for a fire or cause it to spread to another fuel source”

The law does not apply to offices in private domestic accommodation, so what you do in your own home is your own business, but sticking egg cartons to walls is a fire risk with limited acoustic benefits.

It would be safer (and probably more cost-effective) to purchase a fire retardant acoustic foam. 

Even the cheapest and basic acoustic foam is typically flame-retardant according to UL94 HF1.

Here is an example. This link will take you to an acoustic tile on the Gear4Music site but just read the product specification for any acoustic foam to see if it has been fire tested.

The cost of egg cartons versus the cost of acoustic foam?

There is the argument that egg cartons are a cheaper DIY diffuser alternative in comparison to “off the shelf” acoustic foam or an acoustic diffuser, but in today’s world that is not true. Per square meter, it is possible to find acoustic foam which is cheaper. 

Here is an example of a typical egg carton from Amazon.

egg carton amazon

  • To cover 1 square meter of your wall using this egg box would cost around £8.40.

Here is an example of a typical acoustic foam tile from Thomann Music.

  • To cover 1 square meter of your wall using this acoustic foam tile would cost around £7.20

I am sure you could go bargain hunting for better deals, but I see little argument that using egg cartons is significantly cheaper than using acoustic foam.

In comparison to egg cartons, the acoustic foam will:

  • typically offer better sound diffusion. 
  • typically provide some sound absorption. 
  • look better than sticking egg cartons to your wall
  • be flare retardant and less of a fire risk than egg cations

Conclusion:

Egg cartons offer zero soundproofing properties, and any claims that they work as a sound isolator is a myth.

However, egg cartons could double up as a DIY diffuser, therefore I can see why they have remained in the conversation for so long.

The surface of modern acoustic foam is similar in profile to that of an egg carton and with the availability of affordable acoustic foam, there is little advantage in using egg cartons.

Not only is “off the shelf” acoustic foam cheaper, designed for the job and offers some sound absorption, acoustic foam is also much safer to use as it is typically flame retardant, unlike egg cartons which is a fire risk. 

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