Acoustic Curtains for Better Room Acoustics and Less Noise?Nicolas Köhler
In most rooms there are two types of interfering noise. One is the sound that comes from outside and the other is the unpleasant reverberation that occurs when rooms are relatively empty and have many sound-reflecting surfaces. This is where acoustic curtains can help to reduce noise and improve the acoustics of the room. But how do acoustic curtains work and what should you look for when choosing an acoustic curtain? Find out more in this blog post.
Acoustic curtains can do all this
Acoustic curtains reflect and absorb incident sound waves, which is reducing the noise level arriving in the room. This is particularly useful in rooms with traffic noise, loud machinery or other disturbing noises from outside.
Acoustic curtains are also very effective at reducing reverberation by absorbing sound reflections from windows and other hard surfaces. This results in better intelligibility and a more pleasant acoustic environment.
You can also create more privacy by dampening sound between 2 rooms and providing visual separation. This is particularly important in offices, conference rooms or flats.
Thermal protection and dim-out
Acoustic curtains placed in front of windows and glass doors effectively shield rooms from sunlight.
Another important aspect is the visual improvement of rooms with high-quality curtains.
Overall, acoustic curtains offer an effective and versatile way to control and improve the acoustics in a room. They are particularly useful in rooms where good intelligibility, a pleasant sound environment or a reduction of noise and reverberation are required.
Which curtain is right for me?
Material and the combination of materials are probably the most important factors when choosing an acoustic curtain. Acoustic curtains are mainly made of a heavy, well-absorbing textile. Pay particular attention to the weight per unit area of the textile. Materials with a low weight per unit area, i.e. less than 200 g/m², will hardly have a satisfying acoustic effect. The weight per unit area and thus the sound absorption effect can be further increased by using several layers of textile.
Textile has predominantly sound-absorbing properties, but hardly any effect on sound insulation, i.e. noise protection. This requires a heavy, reflective material, for example a PVC film. It reflects the incident sound, so that less noise gets into the room. Textile is also used for the outer layers of these insulating curtains – for purely aesthetic reasons, but also to provide additional absorption and improve the sound in the room. The more layers of textile and foil are used, the more effective is the acoustic curtain. At HOFA-Akustik, we offer acoustic curtains with up to 7 layers by using 4 layers of fabric and 3 layers of PVC film for demanding acoustic tasks.
The size also plays a major role in the acoustic effect. As a rule of thumb: the larger the curtain, the greater the effect.
Nevertheless, it is important to make a distinction between curtains for sound absorption and curtains for the reduction of reverb:
When using a sound absorption curtain, the entire surface through which the annoying sound enters (e.g. the window) must be covered with a soundproof curtain. The curtain should also overlap with the wall on all sides and is ideally continuous from floor to ceiling. If there are gaps, they can noticeably reduce the effect of the sound-absorbing curtain.
If you want to use curtains to reduce the reverb in the room, the total area is the most important factor. Sound-reflecting surfaces such as glass or tiles should be covered as much as possible. However, with incomplete coverage, for example with floating installation, the effect is still given.
It is also crucial to consider sufficient gather for all curtains – not only for visual reasons. This is because the “waves” of the curtain increase their effect. We therefore recommend that curtains for sound reduction be produced twice as wide as the area to be covered (gathering factor 2). For isolating curtains, one and a half times the area to be covered is enough (gathering factor 1.5).
When choosing an acoustic curtain, you should not only pay attention to the acoustic properties. Acoustic curtains can also visually enhance your living and working space. With the right curtain colour, the use of high-quality cover textiles and edge protectors made of imitation leather (borders), you can combine acoustic effect and aesthetic demands.
Furthermore, acoustic curtains can not only provide noise protection, they also help you to darken and insulate rooms. When it comes to darkening, it should be noted that although normal acoustic curtains already absorb a lot of light, they are noticeably translucent, especially in direct sunlight and with a small number of layers. The insertion of a so-called dimout mesh can help here. This has no acoustic properties, but ensures significantly less light transmission and thus creates completely dark rooms, even in daylight.
The suitable attachment
The choice of mounting system, suspension and position is an important factor that should not be neglected in order to achieve the best effect of the acoustic curtain. There are a few points to consider here:
Whether ceiling or wall mounting is the better solution, depends on the conditions at the location. Ceiling mounting with a rail is usually the better choice. The curtain is then fitted with a heading tape and glides elegantly on rollers. Very heavy curtains also hang most securely from the ceiling. In addition, the insulation effect of the curtain is increased because no eyelets are used.
Of course, the installation also depends on the material of the ceiling. If it is a drywall or grid ceiling, the maximum load-bearing capacity of the ceiling is low. For ceiling installation, therefore, the only option is to install a substructure on the drop ceiling, which distributes the curtain weight better, or to install it on the ceiling above, which has a higher load-bearing capacity. However, since these solutions are very costly, wall mounting is a simpler solution. Here, the curtain is either made with eyelets and mounted on a curtain rod or a track is attached with wall brackets so that the curtain can slide on rollers.
When using curtain rods, make sure you use high-quality, stable systems that are designed to withstand a lot of weight. Otherwise, the rods can bend or the wall brackets can tear out.
If you have any questions about curtain installation, the HOFA acoustics professionals will be glad to help you. Together with our installation partners, we will also be happy to take care of the professional installation of your acoustic curtain – especially in particularly demanding situations.
Find your perfect curtain with HOFA
Are you looking for a sound-absorbing curtain or a curtain to reduce reverberation? Then you’ve come to the right place. We have over 15 years of expertise in optimising room acoustics and have already equipped hundreds of rooms with acoustic curtains – from small rehearsal rooms to large assembly halls. Thanks to our in-house sewing department, we can cater to all your wishes and produce the acoustic curtain according to your ideas.
Our ISO acoustic curtain is available in 3, 5 and 7 layers. This type of curtain alternates between textile with a weight per unit area of 300 g/m² and PVC film. With 3 layers, a level reduction of 11 dB is achieved, and with 7 layers, a level reduction of 17 dB (sound reduction index).
If you need a curtain to improve the reverberation time, then the STUDIO acoustic curtain is the right choice for you. It is available with 2 or 3 layers.
Just let us know what kind of noise you have to deal with, as well as the dimensions to be covered and the materials of the wall and ceiling. We will create a suitable configuration according to your wishes. You are also welcome to use our curtain configurator and select your preferred mounting system.
In the following video you can find out how effectively the HOFA Acoustic Curtain ISO 7 helps against annoying environmental noise: