How to make noise insulation in an apartment?


Created on 29.11.2006 15:14.

Updated 05.18.2020 23:35.

Author: Stereo Sound.

Now, in the days of multichannel sound and powerful home theater systems, this topic is becoming relevant. Consider the general aspects of soundproofing.

First of all, it is necessary to determine the problem – whether we want to limit the propagation of sound outside the room or, on the contrary, prevent external noise from entering the room. At first glance, these tasks are identical, in fact, the approach to solving each of them is different.

As a rule, the most common task is to limit the propagation of sound waves outside the home theater or music room.

Any wall of the room, as well as the floor and ceiling, are conductors of wave vibrations (sound waves).

A sound wave, acting on a surface, transmits its vibrations to it. In the adjacent room, the wall acts as a loudspeaker speaker, and its vibrations are converted into sound frequency waves.

The second conductor of sound waves is various crevices and holes in the walls, floor and ceiling. Remember the expression “Water will find a hole“? Sound too. It is important to remember this, because even a perfectly insulated wall with a microcrack will transmit sound to the adjacent room.

So the conclusion is obvious. First, it is necessary to prevent (rather, to limit) the transmission of vibrations by the surfaces of the insulated room. Secondly, prevent the presence of through holes in the walls, floor and ceiling.

How to achieve the first?

A double wall filled with material that absorbs sound frequency vibrations is required. Such materials are available on the market, and it makes no sense to go into details here. But just a double wall is not enough.

It is necessary to create the most mechanically “untied” surfaces, and the inner wall should be relatively mobile, and the outer one should be as immovable as possible.

As a result, we will achieve the following. The sound wave will be received by the inner wall and its energy will be partially absorbed. Further, the vibrations transmitted by the first wall will give their energy to the sound-absorbing material, and only a small part of this energy will reach the outer wall. The outer wall, which is the least prone to vibrations, will extinguish the remaining energy, minimizing the sound transmitted by the structure. The same is true for the floor and ceiling.

An example of soundproofing the ceiling in an apartment. Source

Noise insulation of the ceiling in the apartment is done in several ways. The first wildly difficult option is shown in the picture above. The second option is to use, so to speak, acoustic ceilings, for example, Armstrong. They look much worse than the first option, but the efficiency is very high. Sound insulation can be up to 33 dB.

With floors it is much easier. And you can always put a thick carpet on the floor, which will greatly improve sound absorption.

And so, we have perfectly insulated walls, floor and ceiling. Everything? No! It’s time to remember one more saying: “Where it is thin, there it breaks.” Suppose we even ensured that there are no gaps or holes in the surfaces. But you need to enter the room somehow. This means that we have a door, the very thin place through which the sound will break through, or rather, the sound will seep. Therefore, a special door is needed, but they are produced by only a few companies in the world.

Okay, we have an acoustically sealed space with a lovely impenetrable door. That’s it? Everything is soundproofed.

Now we have a different problem

Remember the law of conservation of energy? So, he hasn’t gone anywhere! This means that the energy of sound waves, which previously went into the outer rooms, remains almost entirely inside. Only a small part of it is absorbed. How does this threaten us? I would like to remind you that the energy of sound waves of different frequencies is different. And the lower the frequency, the more energy. As a result, we will get an overabundance of low-frequency energy in our Home Theater.

Making the bass quieter is not an option, because useful information will start to be lost.

Therefore, it is necessary to use special absorbing and scattering elements of the interior decoration. Schroeder diffusers are ideal here.

Have you forgotten anything? Alas and ah! There is one more thing. If we forget about him, all our previous works will go to dust. This is ventilation. The entire ventilation and air conditioning system in an isolated room must be designed taking into account special requirements and using special “quiet” air ducts.

Now that’s it! It is not easy to create good sound insulation in an apartment, but when it is created, nothing will prevent you from listening to loud music or watching a movie at any time of the day, without disturbing neighbors and household members, and at the same time enjoying all the sound effects of the soundtrack of the film, without being distracted by extraneous noises.