One of the most commonly implemented acoustic treatment materials in home recording studio are the egg cartons. They are very cheap solutions and easy to find. You can find a lot of egg cartons in department store or every time you buy a dozen of eggs in the public market.
Yet the main question remains: “Are they really effective for acoustic home studio treatment?” A quick browse in major recording forums leads to a “NO” answer. Most of them agreed that egg cartons are a waste of time in terms of home studio acoustic treatment. Still they do not provide technical details why it is NOT advisable. I am doing some research fascinated by the egg cartons and investigate why they are not a perfect solution to treat your home recording studio environment.
egg cartons
Sound Absorption Coefficient of Egg Carton
The real answer lies in examining the sound absorption coefficient of egg carton. In most sound engineering literatures, these data is missing. However I did further research and found out a study entitled: “Measurement of the sound-absorption coefficient on egg cartons using the Tone Burst Method” authored by: Quintero Rincon Antonion of Argentina.
The conclusion of the study summarizes the sound absorption coefficient of egg carton in different frequencies, see screenshot below:
egg carton sound absorption data
Surprisingly egg carton does have significant sound absorption particularly for middle and high frequencies. Starting at 1000Hz to 4000Hz, it does reduce the sound at middle frequencies at an absorption coefficient of 0.69.
Comparing this with the common sound absorption coefficients of rigid fiber glass (the standard acoustic treatment material used in recording studios):
fiber glass sound absorption data
Image credits: ethanwiner.com
Based on the data provided; the sound absorption coefficient of egg carton does perform similarly to fiber glass 705-FRK at middle frequencies. However, egg carton does have VERY low sound absorption for 100Hz or the bass frequencies.
This is due to the fact that egg cartoons are not as thick and porous as fiber glass used in acoustic treatment materials. If you plan to use the egg cartons as a sound proofing material; this is not a reliable and effective solution. Some beginners in home recording and studio treatment often have strong beliefs that egg carton drastically absorb the sound in such a way it can be used as a sound proofing materials. This is only a myth.
But looking at the data provided earlier, egg carton will not be a good sound proofing material since it will allow sounds to pass from inside or outside the environment. It is not perfectly absorbent to sound. Also bear in mind that acoustically treating the room (with absorption and diffusion material) is completely different from sound proofing a room.
Conclusions and Recommendations
According to the study “Measurement of the sound-absorption coefficient on egg cartons using the Tone Burst Method”; the egg carton absorbs sound very well above 2 KHz. This means to say that egg cartons is not completely worthless as absorption materials. You can use egg cartons as:
a.) A cheap sound absorber in front of your nearfield monitors. This will do a great job in absorbing mid to high frequencies (starting at 2000Hz and beyond) which travels in line of sight. Bear in mind that this is not a perfect solution and based on the research, egg cartons are poor diffusers so you cannot use them for diffusion purposes. See screenshot below:
diffuser and absorber
But in a very small control room (used for audio mixing), diffusion is not critical and not needed, so you can use egg cartons as a cheap solution to deal with middle frequencies sound absorption.
b.) But take note that egg cartons won’t do good in absorbing bass frequencies at all and it is NOT advisable to entirely rely on egg cartons for both treating bass, mid and high frequencies in your recording studio.
In this case, you should still be using a rigid fiber glass to absorb these frequencies and to use them as bass traps. Thicker fiber glass such as 2 inches absorbs these frequencies very well. You can put this fiber glass in the corners of your room such as this one:
bass traps on corners
c.) Never attempt to use an egg carton to sound proof your studio. Egg cartons are made of thin materials (cartons) which will allow the passage of sound.
Content last updated on July 21, 2012