Home theater sound insulation and shock absorption strategy that you must know

[Abramhham]

Many people use acoustic materials indiscriminately and the sound rooms are filled with sound absorbing materials everywhere. It feels poor. Ask him why he did this, he can’t tell why. He just saw someone else doing this and followed... Some people even made sound absorption. Sound insulation and shock absorption are confused, although they are often performed simultaneously, shock absorption + sound insulation + sound absorption (energy consumption in the cavity). So what is the principle of sound insulation and what materials should be used?

To be soundproof, we must first understand what sound is. The propagation of the vibration generated by the sounding body in the air or other substances is called sound wave. Sound waves are transmitted to all directions with the help of various media. The particle where the sound wave travels vibrates in the vicinity of the equilibrium position along the propagation direction. The propagation of the sound wave is essentially the transmission of energy in the medium.

Here we focus on two points: vibration propagation and energy transfer. Then the starting point for sound insulation should be to block vibration propagation and consume energy.

There is a general rule for sound insulation of partition walls, that is, the heavier the material (area density, or mass per unit area), the better the sound insulation effect. For a single layer of dense and solid wall, every time the areal density doubles, the amount of sound insulation increases theoretically by 6dB. This law is the law of quality.

In addition, any material has an inherent resonance frequency. When the frequency of the sound wave is the same as the resonance frequency of the sound insulation material, resonance will start to occur, and the amount of sound insulation at this frequency will be seriously reduced. The greater the density of matter, the lower the resonance frequency.

Therefore, what we often emphasize when doing sound insulation is "multi-layer composite structure". For example, a layer of 15mm gypsum board is first fixed on the keel, and then a layer of 9mm gypsum board is laid horizontally and crisscross. The effect is even better than that of double-layer 15mm gypsum board. The effect is more ideal. The purpose of this is to reduce the anastomosis effect and improve the sound insulation effect.

In general, if you want to do sound insulation and vibration reduction well, you need to find a way to block the sound propagation path, use high-density, high-damping materials, and composite structures. In the end, the huge sound energy is strangled in the audio-visual room, and at the same time, the external evil sound forces are prevented from invading.

 

[Abramhham]

The soundproofing of the living room theater is basically meaningless. The living room theater is like a wooden barrel leaking around. All we can do is make up the short board, focusing on the doors and windows: grouting the anti-theft door, installing sealing tape and glass on all door joints. The window uses a multi-layer broken bridge structure with vacuum laminated glass, and the amount of sound insulation can reach 34-45 dB, which is basically equivalent to the sound insulation effect of cement walls.

 

[Abramhham]

If the audio-visual room is in the basement, the ground is easy to deal with, and the conditions can be covered with cork floors. If there is a room downstairs, it is recommended to build a floating structure. The simplest floating structure is to lay sound-proof felt and shock-absorbing pad on the ground (sound-proof felt is recommended above the shock-absorbing pad), then lay wire mesh, then pour fine stone concrete, and finally lay floor tiles or floors.

The more ideal method is to use rubber shock absorption module, which has better effect on the impact sound treatment. This method needs to pay attention to the density of the shock absorption block can not be too small, specifically can be operated according to the product manual.

 

[Abramhham]

In some basements, there will be fresh air pipes and sewer pipes. The air flow and the sound of running water will cause noise pollution. For this case, consider using damping and soundproof materials to wrap the pipe. The elastic suspension can also be used for the hanger of the pipe.

 

[SpaceXtt]

The audio-visual room should be a closed and regular rectangle. It is better to seal the doors and windows as much as possible. If it is impossible to seal, it is recommended to use a multi-layer broken bridge structure with vacuum laminated glass windows, and use professional soundproof doors.

 

[LouiseWinner]

The core principle of using elastic force-reducing walls is double-layer sound insulation, blocking rigid connections, and elastic materials to improve sound conduction damping. Because the effect of sound insulation and shock absorption is relatively ideal, it can even play the role of a low-frequency trap, and is widely used by professional audio-visual rooms.

​

There are many types of shock absorbers available on the market, the principles are the same.