Why use an acoustic curtain?

Acoustic, Sound-Absorbing, Soundproofing, and Noise-Blocking Curtains

This article is all about understanding why acoustic, sound-absorbing, and soundproofing curtains are so useful.

You'll also learn about their noise-reducing and noise-blocking effects.

Why use an acoustic curtain?

Decorative and furniture items like sofas, rugs, carpets, and curtains can all help with acoustic comfort. The cool thing about acoustic curtains is that they're the only furniture item you can use in front of a window or bay window. Even though windows let in lots of light, they're inert materials that really contribute to a room's resonance. In some cases, like in schools, open-plan offices or regular offices, windows make up a big part of the 'wall' surface, so it's a good idea to treat them. Curtains can then help control how sound spreads in a room. 

How can you tell if a soundproof and noise-reducing curtain is effective?

Acoustic vs. Soundproof Curtains: How Effective Are They? In the acoustic curtain market, people often mix up soundproofing and acoustic treatment. Curtains are sometimes sold as having a dual function. Soundproofing means keeping outside noise from getting into a room. Acoustic treatment, on the other hand, is about reducing echoes and reverberation within a room.

Acoustic curtains are often marketed for their soundproofing benefits, offering noise reductions between 5 and 18dB.

A 5dB reduction is pretty small, but 18dB offers a real solution, and you'll definitely notice the difference. For instance, a standard interior door already provides between 18 and 27dB of reduction. It's important to understand that this decibel reduction varies depending on the frequency. Depending on your situation, it might be better to choose a curtain that performs well for mid-range/high frequencies. While for others, it could be better to have good performance for mid-range/low frequencies. So, just wanting a curtain with a 17dB reduction doesn't tell the whole story. You should always figure out what specific noises bother you to pick the best solution. To understand this better, you can check out the curve shown below.

Besides reducing outside noise (soundproofing), curtains also provide acoustic absorption. This is often because they're made with multiple layers of textile materials. These materials, combined with an air gap, help dampen sound.

So, these two features are a significant bonus for a room's acoustics. However, it's worth noting that even the best curtains are often suggested as supplementary solutions or finishing touches in a larger project. This is mainly because a curtain only works when it's closed in front of the window.

But when you have lots of windows or bay windows, the goal is usually to let in more light and open up to the outside... which is the opposite of what a curtain does. 

Effectiveness: Finding the Best Soundproof Curtain 

Acoustic curtains help reduce noise thanks to two main operating principles. 

1. First, through porosity: the curtain is made of thick, dense fabrics that absorb sound thanks to their thickness and an air gap.

2. Second, through the mass/spring effect: the curtain consists of successive layers of different materials that combine to optimize absorption. Think of it as one layer absorbing, and another reflecting energy...

Here are some key points to remember: 

• The thicker the curtain, the better it works.

• The further the curtain is from the wall/surface, the better it works.

• The more surface area the curtain covers, the better it works.

There are several types of acoustic curtains:

• The Conventional Curtain

• The Japanese Panel Curtain

Curtains that perform well acoustically are often those that are:

• Technical, made of multiple layers.

• Blackout

• Thick

• Heavy

• Set away from the wall

• Made of natural felt

• Made of velvet

Thick noise-reducing and soundproofing curtain

As we just mentioned, the curtain's thickness will affect how well it absorbs sound. So, it's best touse a thick curtain and check out the material it's made from. Test reports can also give you an extra hint about the quality. But, you really need to scrutinize them carefully. We'll dive deeper into that later.

Soundproof and noise-reducing curtains: what kind of decibel reduction can you expect (12 dB, 20 dB, 21 dB, or 30 dB)?

A pretty basic curtain will give you a reduction of around 5 to 7 dB. This is the standard reduction for what's called an acoustic curtain. These curtains are either quite thick or made with a thin layer of 'metallized' fabric, similar to garage insulation. A higher-quality curtain will perform better, offering between 12 and 18 dB. These curtains will have multiple layers. Some will be very heavy and thick because they're made of quality fabrics combined with felt or fleece. Others, designed with special care, can stay lightweight thanks to research into materials and technical design. They're made of heavy textiles, coatings, metallized sheets, and fleece. 5 and 7-layer soundproofing curtains: acoustic and noise-reducing performance Technical soundproof, acoustic, and noise-reducing curtains can even have 5 or 7 layers!

The more layers a curtain has, the better it can perform (of course, depending on the materials used). However, it will also be heavier and, therefore, less easy to handle.

Plus, thanks to its properties, a noise-reducing curtain will also significantly cut down on room reverberation. But, for this second benefit, the curtain needs to be drawn all the time!

Uses for soundproof and acoustic curtains

Acoustics are super important in lots of situations. So, curtains can be really useful for both homes and businesses. Soundproofing Curtains As we explained earlier, a curtain adds extra sound insulation. So, it can help you get more peaceful nights if you live near a road. But it won't stop you from hearing your neighbor's party.

Home Cinema Acoustic Curtains

Acoustics are super important for a home cinema. We explain all about it in our tutorial on cinema room acoustics. If your room is particularly large and open, these curtains will be a real bonus for immersing yourself in your movies. They're great for both acoustics and reducing light in the room.

Acoustic Curtains for Studios

An acoustic curtain is also really useful for a studio:

• Whether it's an apartment

• Or a music studio

Indeed, good acoustics offer many benefits for both these environments.  

Soundproof Velvet Stage Curtains

Some performance halls or theaters might use velvet curtains to define the stage. Since they're quite thick, they absorb sound really well, plus they look super high-quality.

Acoustic Curtains Made of Rubber

As we'll see later, the number of layers will affect how well a curtain performs. So, a basic rubber acoustic curtain won't be very effective.

Soundproofing Curtains for Room Dividers

A curtain can be handy for soundproofing an appliance in an open room, for 'separating' two living spaces, or simply for keeping a window open and stopping noise from spreading. However, the curtain won't give you perfect insulation, even at 18 dB.

Acoustic, Sound-Absorbing, and Noise-Reducing Curtains for Entrance Doors

As explained earlier, putting a curtain at your front door can also make sense.

Industrial Noise-Reducing Curtain

A curtain can be useful in an industrial setting. It's even more necessary when you have rooms with large glass surfaces.

Soundproofing Curtain for Homes

A curtain can improve your home's acoustics. So, putting one up can be really helpful if you have a room with reverberating materials, a large space, or specific musical needs (like a hi-fi room, studio, etc.).

Acoustic Curtain for Bedrooms

As we mentioned earlier, an acoustic curtain will be perfect for improving your sleep.

Professional Acoustic Curtain

An acoustic curtain can also bring benefits in a professional setting. In some cases, its cost might even be covered by public subsidies. Feel free to contact us to learn more!

The Price of Noise-Reducing Fabric per Meter

Just like with many acoustic products, thinking in terms of price per m² isn't very helpful. It's better to include other indicators, especially acoustic performance per m², when comparing products. 

On top of that, just like an acoustic panel, an acoustic curtain is more technical than it seems. Having one custom-made by an upholsterer would cost you a lot more than buying a ready-made one.

Affordable Soundproof and Noise-Reducing Curtains: What's the Right Price?

The price will depend on the results you're looking for. As is often the case, there are curtains available at all price points. The cheapest ones will be offered between €90 and €129. However, professionals don't really recommend them because they're not very effective. A high-performance acoustic curtain can cost between €250 and €600 per width. At Cotton Silence, we offer a model that combines all the highest acoustic performances.

Alternative to Galon, Moondream, Ikea, Leroy Merlin, Castorama, and Amazon Soundproof Curtains As mentioned before, the number of layers and the complexity of a curtain will impact its performance. The problem is that most of these sites offer basic curtains. If you look at most customer reviews, you'll see that the effectiveness of these products is very mixed. This is reflected in the price: it's indeed low. So, just like in many markets, you need to invest a certain amount to get a decent result.

Also, if you're buying these types of products for a comprehensive sound insulation and acoustic treatment project, proper installation is crucial. It requires expert advice, which you won't find on these sites.

Limitations of Acoustic Curtains

Curtains and Sound Performance

We covered this at the beginning of this article. As we mentioned, a curtain only has limited use for sound insulation.

The Problem with an Open Curtain

The thing with acoustic curtains is that they're often left open. But, they'll definitely be more effective when closed because they'll cover a larger area. This is especially true since, in most cases, they cover highly reverberant materials (like large windows). These can negatively impact your acoustics. 

Test Reports

It's important to be wary of acoustic test reports for curtains. You also need to pay attention to the calculation methods used for noise reduction with these curtains. We often see many products presented with an "NRC" coefficient, displayed in the same way as the "Aw" coefficient. However, technically, they're not the same thing.

So, ideally, you should have a complete test report in alpha sabine, expressed frequency by frequency. This way, it's better to calculate the gain index in terms of TR (reverberation time) reduction with curtains open. In reality, they're more often open than closed, so the treatment surface isn't the same.

Also, as mentioned earlier, a curtain needs to be closed to achieve its full effectiveness.

Just so you know, thin, see-through curtains won't do the trick. You'd basically be losing out on the benefits of your windows.

So, what's the verdict on acoustic, noise-reducing, and soundproof curtains?

So, soundproof curtains can definitely help with your home's acoustics. For them to work properly, they need to be 'open' – meaning fully unfolded. You can use them in lots of different situations. How well they perform really depends on how thick they are and how they're installed. While test reports are a good way to get an idea, it's super important to check out the testing method to make sure the results haven't been exaggerated by the process.