Do soundproof curtains really work?

Many curtain manufacturers claim their curtains are soundproof, but in reality, they don't provide much sound insulation after purchase. This is because the manufacturers' claims are somewhat exaggerated, and people who buy soundproof curtains place all their hopes on them. As the saying goes, the greater the expectation, the greater the disappointment, so many people feel that soundproof curtains are not very effective.

Do soundproof curtains actually work?

First, it's important to understand the role of soundproof curtains in the overall sound insulation of a house.

The key to effective outdoor noise insulation lies in the selection of windows; soundproof curtains primarily serve as a supplementary measure.

So, are soundproof curtains actually useful? Yes, they are. For example, if your windows have already blocked out outdoor noise to 40 decibels, but you still find it noisy and you can't modify or add more windows, and you want to further reduce it by 5 to 8 decibels (low frequencies might be around 5 decibels, and high frequencies are close to 10 decibels), then you can only use soundproof curtains.

Although the reduction is small, it's especially noticeable when noise levels are already around 35 or 40 decibels. This is because most people can't feel any noise below 30 decibels.

Secondly, we need to know how soundproof curtains actually block sound.

So how do you choose soundproof curtains?

1. For soundproof curtains, the most important thing is soundproofing. The thickness and density of the soundproofing layer must be thick and dense to ensure good sound insulation.

2. Choose multi-layered curtains with both sound insulation and sound absorption structures for optimal soundproofing. Curtains can only block some noise; some will inevitably penetrate. Therefore, sound-absorbing materials are needed to attenuate the transmitted sound waves and achieve optimal sound absorption. (The sound-absorbing structure is similar to a waffle. For even better noise reduction, the Italian Aitex Focus Alfa curtain fabric, designed with a superior microstructure, is ideal, but it's extremely expensive.)

3. Most importantly, a special coating, especially a polymer material like acrylic resin fiber, needs to be added to increase overall airtightness, making it harder for sound waves to penetrate. (Acrylic resin is a new type of foaming agent; it works very well as a protective sound insulation layer under the car.)

Because acrylic resin fiber is a polymer, it generally exhibits characteristics of both viscous liquid and elastic solid (viscoelastic material). Damping materials (viscoelastic damping materials) are typically composed of polymers as the base material with varying viscoelastic ratios. This material possesses energy storage capacity in its elastic component and energy dissipation capacity in its viscous component.

• When the elastic part is subjected to alternating stress (when noise passes by), the elastic part stores energy like mechanical energy or potential energy, and then returns it to the outside world.
• The viscous part dissipates the other part of the energy (noise) by converting the energy into heat energy, and at the same time, the amplitude of the vibration will decrease over time, which will play a role in damping the vibration, thus reducing the noise.

Indoor cabins of vehicles like high-speed trains, cars, and airplanes utilize polymer materials for sound insulation. However, due to quality and lightweight requirements, the design and application of polymer sound insulation materials necessitate maximizing sound insulation within the corresponding noise frequency range and maintaining a thin and lightweight structure. Furthermore, the overall sound insulation requirements must be considered in conjunction with other components. Professional soundproof curtains must also adhere to these design principles to ensure effective sound insulation (though domestically produced soundproof curtains still require further improvement in this area).

4. Most importantly, many soundproof curtains on the market meet the requirements in other aspects, but they still cannot achieve good airtightness. This is because although the front is good, there will still be sound leakage at the top. It is best to have matching curtains that can block sound at the top.

5. Noise reduction performance of the fabric itself: Tussah silk > Polyester > Acrylic > Cotton and linen > Australian wool

in conclusion:

To achieve the desired soundproofing effect from curtains, every detail must be meticulously handled to effectively block out noise (around 10 decibels for high frequencies and around 5 decibels for low frequencies).

Article source: Zhihu