The aim of this article is to understand the interest of an acoustic, insulation and sound absorbing curtain. You will learn more about its anti and noise cutting effect.

Why use an acoustic curtain?

Decorative elements and furniture such as sofas, carpets and curtains can provide acoustic comfort.

The interest of an acoustic curtain is that it is the only furniture element that can be used in front of a window or bay window.

Windows, even if they bring a lot of light, are inert materials that strongly participate in the resonance of a room.

In some cases, such as in schools, open spaces or offices, windows represent an important part of the “wall” surface and should be treated.

The curtains will thus make it possible to regulate the propagation of sound in a room.

How to know if a insulation and anti-noise curtain is effective?

Acoustic and sound curtain, how effective?

In the acoustic curtain market, the amalgam is often made between soundproofing and acoustic insulation.

Curtains are sometimes sold to have the double function.

The sound insulation is to not let the sound from outside a room “enter” into it. Acoustic treatment consists in reducing echoes and reverberation of a room.

Acoustic curtains are often sold to achieve sound insulation gains, with noise reductions between 5 and 18db.

A gain of 5db is relatively small, while 18db provides a real solution and the difference will really be heard. For example, a non-acoustic interior door enable to already between 18 and 27db of reduction.

In addition to this gain in noise reduction from the outside to the inside (sound insulation), curtains offer sound absorption. This is often the case because their design is made with textile materials in different layers. Thus, these materials in combination with an air plenum, provide acoustic damping.

These 2 aspects are therefore a significant plus for the acoustics of a room.

However, it should be noted that curtains, even the best ones, are often proposed as an additional or finishing solution in a global project.

This is mainly due to the fact that a curtain will only work if it is closed in front of the window.

However, in cases where there are many windows or bay windows, the aim is to gain clarity and open outwards – which is the opposite function of the curtain.

Efficiency: determining the best acoustic curtain

The acoustic curtain allows to attenuate the noises thanks to 2 main principles of operation.

1. The first by the porosity: the curtain is composed of thick and dense fabrics, which absorb sound thanks to its thickness and air plenum.
2. The second by the mass / spring effect: the curtain is composed of successive layers of different kinds that combine and optimize the absorption. A layer of absorption, a layer that reflects the energy …

The following points should be noted :

• The thicker the curtain, the better it works
• The farther the curtain is from the support, the better it works
• The more surface the curtain covers, the better it works

There are several types of acoustic curtains :

• The conventional curtain
• The curtain type Japanese canvas

The curtains that will be good acoustically are often the curtains :

• Technical, composed of several layers.
• Occultant
• Thick
• Heavy
• Away from the wall
• In natural felt
• In velvet

Thick curtain for anti-noise and sound insulation

As stated just before, the thickness of the curtain will affect the absorption quality of the curtain.

It is therefore preferable to use a thick curtain and look at the material used. Test reports can also be an additional indication to ensure quality. However, they should be scrutinized with special care. We will come back to this later.

Anti-sound and noise curtain, what decibel gain can be expected (12 db, 21db, 30 db)?

A relatively basic curtain will allow a reduction of the order of 5 to 7db.

This corresponds to the standard reduction of a so-called acoustic curtain. These curtains are either relatively thick, or composed of a thin layer of fabric “metallized” as for the insulation of garages.

A better quality curtain will have performances between 12 and 18db.

These curtains will have several layers. Some will be very heavy and thick because they are made of quality fabrics and combined with felt or fleece.

Others, which are the subject of special attention, can remain light thanks to research on materials and technicality. They are composed of heavy textiles, coatings, metallized sheets and fleece.

The technical, acoustic and anti-noise curtains can thus integrate 5 or even 7 layers!

In addition, because of its properties, a curtain that reduces noise will also tend to significantly reduce the reverberation of the room. However, in this second case, the curtain must be drawn permanently!

The uses of a sound insulation and acoustic curtain

Acoustics are important in many situations. In this sense, curtains can be useful for a home or a professional.

Curtains for sound insulation

As explained above, a curtain provides reinforcement in terms of sound insulation. Thus, it can help you to spend more serene nights if you are close to a road. But it will not prevent you from hearing the party going on at your neighbor’s house.

Acoustic curtain for home theater

Acoustics are essential for a home theater. This is what we explain in our tutorial on the acoustics of a movie theater.

If your room is particularly large and open, they will be a real plus for immersion in your movies. Both for the acoustics and for reducing the light in the room.

Stage velvet sound insulation curtain

Some theaters or concert stage may use velvet curtains to delineate the stage.

Being relatively thick, they dampen the sound in a very correct way, in addition to being very qualitative.

Sound insulation curtain for room separation

A curtain can have a phonic interest to isolate an appliance in an open room, to “separate” 2 living rooms, or simply to keep a window open and prevent noise from spreading. However, the curtain will not provide perfect insulation, even at 18db.

Acoustic, soundproofing and anti-noise curtain for front door

As explained earlier, placing a curtain at the front door can also make sense.

Industrial anti-noise curtain

A curtain can be used in an industrial setting.

This is all the more necessary when you have rooms with a large glass surface.

Home soundproofing curtain

A curtain can improve the acoustics of your home.

Placing one can be of interest if you have a room composed of reverberant materials, a large volume or with musical constraints (hi-fi room, studio, …).

Acoustic curtains for bedroom

As mentioned before, the acoustic curtain will be perfect to improve your nights.

The price of a fabric anti noise per meter

As with many acoustic products, reasoning in terms of price per m² is of little interest. It is preferable to include other indicators, such as acoustic performance per m² to compare products. This is what we explain in our tutorial on the price of acoustic products.

In addition, like an acoustic panel, an acoustic curtain is more technical than it seems. Having it made by an upholsterer would cost you considerably more than buying a ready-made one.

Cheap anti sound and noise curtain: what price to put?

The price will depend on the result you want. As often, there are curtains at all prices.

The cheapest will be offered between 90 and 129€. However, they are not so much recommended by professionals because they are not efficient enough.

A high performance acoustic curtain can cost between 250 and 600€ per fabric width.

Limitations of the acoustic curtain

Curtain and sound insulation performance

We dealt with this issue at the beginning of this article. As indicated, a curtain has only limited value for sound insulation.

The problem of an open curtain

The problem with the acoustic curtain is that it is often open.
However, it will necessarily be more efficient closed because it will cover a large area.

This is especially true since, in most cases, it covers very reverberant materials (bay windows). These will have a negative impact on your acoustics. Please read our tutorial on noise absorption in a room to learn more.

Test reports

It is important to be wary of acoustic test reports from curtains. It is also necessary to pay attention to the methods of calculation of noise reduction with these curtains.

Indeed, we see many products presented with a “NRC” coefficient. It is presented in the same way as the “Aw” coefficient. However, technically, it is not the same thing.

Therefore, the ideal is to have a complete alpha sabine test reports, expressed frequency by frequency.

Thus, it is preferable to calculate the gain index in terms of RT (reverberation time) reduction with open curtains. In fact, in reality, they are more often open than closed: the treatment surface is therefore not the same.

Moreover, a curtain, as previously mentioned, must be closed to obtain its full efficiency.

Also be aware that thin and transparent curtains do not work. You therefore lose the interest of your glass surfaces.

Conclusion, the acoustic, anti-noise and sound insulation curtains: what to make of it?

Acoustic curtains are therefore useful for your acoustics. To be efficient, they must be “open”, that is to say unfolded.

They can be used in many circumstances. Their performance will depend on their thickness and their implementation. Even if the test reports are a relevant indicator to make an opinion, it is essential to look at the test method to see if the performance has not been amplified by the process.