Surely on more than one occasion you have been one of those people who thought that egg cups were the best and cheapest insulation that could be had for a rehearsal room or a room, for example. The truth is that there is a great myth about this class of material and its results as an acoustic insulator. At the end of the eighties in Spain, many music groups began to use cardboard egg cups in their rehearsal rooms to have “better acoustics”. It is not known if it is because of the material with which they are made (a kind of fairly compact thin cardboard) or because their appearance is similar to that of the alveolar panels used in some recording, dubbing and rehearsal studios. But the truth is that egg cups have established themselves as an increasingly used acoustic conditioning material.
The difference between conditioning and acoustic conditioning What many people don’t know is that there is a big difference between conditioning and conditioning. We can say that the conditioning is what can be achieved thanks to different construction solutions for ceilings, walls and the installation of floating floors, false ceilings and walls, etc. In this way, the objective is to protect the enclosure from the noise produced from and towards the outside or the premises that are very close together. On the other hand, the acoustic conditioning is focused on improving the acoustic quality within the same venue in which a sound is being generated, such as in a music rehearsal room. a band.
Breaking the myth of the egg cup Egg cups do not have the capacity to increase the acoustic conditioning of a room, although when it comes to conditioning, two basic properties of materials must be taken into account: absorption and diffusion. Any kind of sound is composed of different frequencies, therefore a sound does not have a single frequency but a varied group of them. In this case, our ear can only capture those that are in a range between 20 Hertz and 20 Kilohertz. The frequencies that we perceive best are those that are between 500 Hertz and 4 Kilohertz. Due to the way in which the egg cups have, they could have some diffusion, but because they do not have a large size in terms of depth, they only achieve it with frequencies that are above approximately 8 Kilohertz. . The diffusion offered by the egg cups that we all know can be considered reduced, occurring at frequencies that are less perceptible to the human ear and that, due to the very definition of wavelength, are attenuated more quickly. For all this, it can be said that the egg cups is a myth since they do not provide any kind of acoustic conditioning and they have Very low indices of both diffusion and acoustic absorption. The most advisable thing is to have the advice of a firm specialized in acoustics and soundproofing if we really want to achieve the objective that is sought.