If you have been into a small rehearsal studio or a friend’s rehearsal cellar, you’ve likely noticed a portion of the space (most probably the ceiling) is coated with egg cartons. Unsure whether you’ve entered a practice space or a shady egg-packing operation, you ask the owner what that’s all about, wherein he says that the egg cartons serve as soundproofing by absorbing the sound because of its distinctive form. You find yourself having difficulty believing him as you walk out of the studio after practice with a really bad case of tinnitus.
Egg cartons for soundproofing is maybe among the most well-known myths about acoustics. Whether or not this belief was set by specialists or DIY enthusiasts allow me to break this myth by telling you that egg cartons do absolutely nothing for soundproofing. This ought to be obvious to you once you’ve got a friend shout directly in your ear with only a egg tray in between the two of you.
In the realm of acoustics, there are different frequencies of sound that interact in many different ways with the environment around them. High frequency sound waves, such as the noise of a high pitched shriek or your bothersome Epson LX-300 dot matrix printer, are easily absorbed by layers of porous material like cloth, fiberglass and carpets.
Low frequency noise, such as the ones heard at hip-hop/dance nightclubs, bass guitars and kick drums aren’t readily as absorbed (an excuse why you listen to only the bass when you’re in the vicinity of a club or a car with subwoofers passes by with their windows up).
These kinds of frequencies could be consumed by constructions that have a greater density and mass, such as concrete walls and increasingly thick layers of fiberglass. While an egg carton may absorb any high frequencies, it won’t prevent any low frequencies from passing through it, and is therefore a bad choice for noise cancelling. Egg cartons can be used for sound treatment, however, as a poor-man’s diffuser.
With its very definition, noise proofing is the inhibition of noise from escaping a given space in which it is allowed to disperse. If even the slightest measure of audio is heard from a”sound proofed” area, that place is no more considered sound proof.
Sound treatment, on the other hand, is that the manipulation of an area’s reaction to frequencies to create a sonically balanced and more positive listening/performance area. Sound treatment can be accomplished through absorption, reflection and diffusion (egg cartons may fall into this class ).
If you’re helping someone set up a rehearsal rooms Toronto or are making one at your own home, forget the egg carton fantasy and look for more effective means of treating your space. Developing a sound proof chamber may be past most budgetary capability of hobbyists (it is essentially creating a room in a room), however acoustic audio treatment can be had at a reasonable price.