How many sound absorbers do you need?

Creating a pleasant sound environment is about understanding how much sound-absorbing material is needed to effectively reduce reverberation and unwanted sound reflections. By using the right amount of sound absorbers, you can improve the acoustics in everything from offices and schools to restaurants and home environments. With our reverberation time calculator, you can easily figure out how much surface area should be covered to achieve a more pleasant and subdued sound environment.

The goal of sound absorption is to reduce echo and noise without creating an overly muffled soundscape. A good guideline is to cover at least 20-30% of the room's total surface area, but in some cases more may be needed depending on the size of the room, choice of materials, and sound issues. The ceiling is often an optimal place to start with sound absorption, as it is a large, free surface where sound waves are highly reflected. Walls and corners are also important areas to focus on to achieve even sound distribution.

The installation of sound absorbers can be adapted to the needs and aesthetic requirements of the room. For a visible installation, brackets and fasteners can be used on both walls and ceilings. If you prefer a more discreet solution, there are hidden mounting options that blend into the room. Wire systems are a flexible solution for ceiling mounting, while Velcro strips can be a convenient option for walls where you want a removable solution. For corner mounting and diagonal placements, there are specially adapted fasteners that help create effective and balanced sound absorption throughout the room.

By carefully planning the placement and quantity of sound absorbers, you can create harmonious and pleasant acoustics that improve both the working environment and well-being. Use our calculator to get an accurate estimate of how many sound absorbers you need for your specific room.

Calculate the reverberation time in your room and optimize the acoustics

Understanding the reverberation time in a room is crucial for creating an optimal sound environment. Reverberation time describes how long a sound continues to be heard after the sound source has fallen silent. By calculating this time, you can get a clear picture of how much sound absorption is required to reduce echo and improve the acoustics in the room.

With our tool, you can easily calculate the reverberation time and adapt sound-absorbing measures to the specific needs of the room. By optimizing the acoustics, you create a more comfortable environment where speech intelligibility is improved and the sound level is more balanced. This is especially important in office environments, conference rooms, schools, and homes where a clear and comfortable sound environment is crucial for productivity and well-being.

How much sound absorption is needed?
To achieve balanced acoustics, it is recommended that at least 20-30% of the room's surface area be covered with sound absorbers. The ceiling is an ideal place to start sound absorption as it often offers the largest surface area without furniture or other obstacles. Installing sound absorbers on the ceiling significantly reduces reverberation, resulting in a more subdued and comfortable sound environment.

If you want to further improve the acoustics, the walls can also be covered with sound absorbers. Strategic placement where sound reflections are strongest provides the most effective sound attenuation. By combining ceiling and wall absorption, you can create a more controlled sound environment without disturbing echoes.

Mounting options for sound absorbers
To ensure smooth installation and suitability for different room environments, we offer several mounting options. Ceiling absorbers can be installed with wire systems, visible brackets, or vertical brackets for suspended ceilings. If a more discreet installation is desired, wire baskets can be used to create a stylish and functional solution.

For wall mounting, sound absorbers can be attached with visible brackets or concealed mounting brackets for a minimalist look. Velcro strips can also be used for flexible and easy installation. If you want to cover corners or diagonal surfaces between the ceiling and wall, special brackets and diagonal mounting options are available to maximize sound absorption in hard-to-reach places.

Improve the sound environment with the right acoustic solution
By calculating the reverberation time and adjusting the room's sound absorption, you can create a more comfortable and functional environment where the sound level is balanced and echoes are minimized. Whether you are optimizing an office, a home environment, or a larger public space, it is important to choose the right combination of sound absorbers and mounting solutions.

With our flexible mounting options and high-performance sound absorbers, you can easily adapt the acoustics to your needs. By covering the right surfaces and using a well-planned installation, you can create a harmonious sound environment where both productivity and well-being are improved.

Calculate the reverberation time

What is reverberation time and why is it important?

Reverberation time is a measure of how long a sound continues to be heard in a room after the sound source has stopped. It is defined as the time it takes for the sound level to decrease by 60 decibels and is measured in seconds. Reverberation time plays a crucial role in how we perceive the sound environment and affects everything from speech comprehension to musical experiences.

A room with a long reverberation time can create an echoing and unbalanced sound image, making it difficult to perceive speech clearly. This can be particularly problematic in classrooms, conference rooms, and work environments where communication needs to be clear and distinct. On the other hand, too short a reverberation time can make the sound experience feel muffled and lifeless, which can be negative in, for example, concert halls where a certain amount of reverberation is desirable to give the music a richer sound.

What factors affect reverberation time?

The reverberation time in a room is influenced by several factors, with the size, shape, and materials of the room being crucial. Larger rooms with high ceilings tend to have longer reverberation times because the sound waves have more space to reflect before they are dampened. The surfaces in the room also play a major role – hard materials such as concrete, glass, and tile reflect sound, which prolongs the reverberation time. Soft and porous materials such as carpets, curtains, and sound-absorbing panels, on the other hand, help to reduce reverberation by absorbing sound waves instead of reflecting them.

The room's interior design also affects the sound environment. A minimalist room with many hard surfaces will have a longer reverberation time compared to a room with lots of textiles, upholstered furniture, and sound-absorbing elements. By strategically placing sound absorbers on ceilings, walls, and in corners, the reverberation time can be optimized to create a more pleasant and balanced sound environment.

Optimal reverberation time for different rooms and spaces

Reverberation time is a crucial factor for the sound environment in different types of rooms and premises. By adapting the reverberation time to the room's use, you can improve speech intelligibility, reduce disturbing noise, and create a more pleasant atmosphere.

Office environments – Create a productive working environment
In offices and meeting rooms, reverberation time should be kept relatively short, usually between 0.4 and 0.8 seconds. Too long a reverberation time can lead to increased noise levels, which negatively affects concentration and productivity. In open-plan offices, where sound from conversations, keyboards, and other sources spreads easily, it is particularly important to have a controlled reverberation time. Using sound absorbers on ceilings and walls can reduce reflections and create a more focused working environment.

Educational environments – Improved speech perception and learning
In classrooms, lecture halls, and auditoriums, a reverberation time of 0.4 to 0.6 seconds is optimal. Shorter reverberation improves speech intelligibility and reduces background noise interference, making it easier for pupils and students to focus. Excessively long reverberation times can make the teacher's voice more difficult to hear, which impairs learning. By combining ceiling absorbers and wall panels, the acoustics can be optimized for clear communication.

Residential – Create a pleasant and peaceful atmosphere
In living rooms, dining rooms, and bedrooms, a reverberation time of between 0.5 and 0.9 seconds is often ideal. This level contributes to a pleasant sound environment without the sound feeling too muffled or lifeless. In kitchens and bathrooms, where hard surfaces such as tile and stone dominate, a slightly shorter reverberation time of 0.5 to 0.8 seconds can reduce sharp sound reflections and create a more harmonious sound environment.

Public spaces – Balance between liveliness and clarity
In airports and train stations, the reverberation time should be between 0.9 and 1.5 seconds. This level ensures that announcements and communication are clearly heard while the soundscape remains natural. Shopping centers should have a reverberation time between 1.3 and 2.0 seconds to create a pleasant atmosphere where the sound level is kept at a manageable level.

Healthcare facilities – A soothing sound environment for patients and staff
In patient rooms, a short reverberation time of 0.4 to 0.6 seconds is preferable to minimize disturbing sounds and create a calming environment. Corridors and waiting rooms can have a slightly longer reverberation time, between 0.6 and 1.0 seconds, to balance the sound environment without creating a feeling of isolation. In treatment rooms and examination rooms, the reverberation time should be between 0.4 and 0.8 seconds to ensure clear communication between healthcare staff and patients.

Industrial environments and warehouses – Safety and clear communication
In warehouses, a reverberation time of between 0.6 and 1.0 seconds is appropriate to reduce noise levels and improve speech intelligibility between staff. In industrial environments where machines generate high noise levels, it is particularly important to control the reverberation time, usually between 0.6 and 1.0 seconds, to protect workers' hearing and create a more ergonomic working environment.

Studios and cinemas – Precise control of sound
In podcast and radio studios, the reverberation time should be between 0.4 and 0.6 seconds to ensure that speech remains clear and distinct without unwanted reflections. Music studios used for recording instruments and vocals should have a reverberation time between 0.6 and 1.2 seconds, depending on the style of music. Mixing and mastering studios require shorter reverberation times, between 0.2 and 0.5 seconds, to provide accurate sound reproduction.

Theaters, cinemas, and concert halls – Create an optimal listening experience
In theaters and cinemas, the reverberation time should be between 0.9 and 1.2 seconds to balance speech intelligibility and sound experience. Concert halls used for classical music should have a reverberation time of 1.6 to 2.2 seconds to give the music a rich sound. Pop and rock music benefit from a shorter reverberation time, between 1.0 and 1.5 seconds, to maintain a clear and dynamic sound image.

Churches and chapels – Amplification of music and speech
In larger churches, a reverberation time of between 1.8 and 4.0 seconds is common, depending on the design and use of the room. A longer reverberation time amplifies choir singing and organ music, but too long reverberation times can make speech difficult to understand. By balancing sound absorption and diffusion, an optimal sound environment can be created.

Summary and acoustic optimization
The optimal reverberation time varies depending on the purpose of the room and the activities carried out there. By using sound absorbers in strategic locations, the reverberation time can be adjusted to create acoustics that are tailored to the needs of the room. Ceiling absorbers, wall panels, and corner absorbers can all play a crucial role in optimizing the sound environment.

Reverberation time in rooms without sound absorbers – why sound becomes problematic

When a room lacks specific sound-absorbing materials, sound waves tend to be reflected to a high degree. The absorption capacity of the room's surfaces becomes low, especially if they consist of hard materials such as concrete, glass, or untreated wood. These materials generally have very low absorption coefficients, which means that they absorb hardly any sound at all. Instead, the sound bounces back and forth between the surfaces, creating a long reverberation time and a sound environment that is perceived as echoey and noisy.

In rooms where no sound absorption is installed, the reverberation time can be significantly higher than is desirable for a comfortable sound environment. The longer the reverberation time, the more difficult it is to hear and understand speech, which affects both concentration and well-being. This is particularly problematic in workplaces, schools, and public environments where clear communication and focus are crucial.

Common materials and their low absorption capacity
Hard and smooth materials reflect sound instead of absorbing it, causing sound to bounce between walls, floors, and ceilings. Here are some examples of typical absorption coefficients for common surfaces in a room without sound absorbers:

Concrete walls
Concrete walls have an absorption coefficient of around 0.01 to 0.10, which means they reflect almost all sound.

Glass windows
Glass windows absorb only around 0.05 of sound waves, making them ineffective at reducing reverberation.

Hard wood
Hard wood, such as untreated wooden floors or wall panels, has an absorption coefficient between 0.05 and 0.15, which makes it slightly better than concrete but still insufficient for a good sound environment.

Brick walls
Brick walls absorb sound even less effectively, with a coefficient of around 0.02 to 0.05.

Painted plaster
Painted plaster has an absorption capacity between 0.05 and 0.10, which means that it only contributes marginally to sound absorption.

These figures clearly show that a room without sound-absorbing materials will have a very high reverberation time and a poor sound environment. This means that speech becomes difficult to distinguish, sound levels can feel stressful, and echoes become a source of disturbance.

Consequences of high reverberation time in rooms without sound absorbers

In a room where all surfaces are made of hard materials and no sound absorption is installed, the reverberation time can be extremely long. This means that sound continues to bounce around the room for several seconds after the sound source has stopped. Such a sound environment affects productivity, well-being, and health.

Poorer concentration and work performance
In work environments, it becomes more difficult to focus when the noise level is high and echoes amplify disturbing sounds. Sounds from conversations, keyboards, and other office noises can overlap and create a stressful soundscape.

Impaired communication
In schools and meeting rooms, it becomes more difficult to understand speech due to reflective sound waves. This has a negative impact on students' learning and can also lead to misunderstandings in work meetings.

Increased stress and fatigue
High reverberation time can create a stressful sound environment that contributes to mental fatigue and increased stress levels. Prolonged exposure to a noisy environment can also have a negative impact on hearing.

Poor sleep quality
In homes, echoing sounds can make it more difficult to relax and sleep. This is especially true in bedrooms with hard surfaces where sounds from other rooms can be amplified.

How to improve the sound environment in a room without sound absorbers
To reduce reverberation time and create a more comfortable sound environment, the room needs to be supplemented with sound-absorbing materials. An effective solution is to install sound absorbers on ceilings, walls, and other strategic surfaces. The ceiling is particularly important because it is a large reflective surface and often has plenty of space for sound-absorbing materials. Another important measure is to cover at least 20-30% of the room's surfaces with sound absorbers. This significantly reduces echo and creates a more controlled sound environment. Wall panels, acoustic ceilings, carpets, and textiles can also help to dampen sound waves and create more pleasant acoustics. By understanding how hard surfaces affect the sound environment and taking measures to absorb sound reflections, you can create a more comfortable room that is optimized for communication, work, and well-being.

Placement of sound absorbers – optimize acoustics for a better sound environment

Placing sound absorbers in the right places in a room is crucial for creating pleasant and well-balanced acoustics. Once you have identified how much surface area needs to be covered to reduce reverberation and disturbing noise, the next step is to decide where to place the sound-absorbing materials. By strategically choosing the right placement, you can maximize the effect of sound absorption and create an environment where the sound image is clear, pleasant, and free from echo. One of the most effective places to start is the ceiling, as it is often an unused surface where sound can reflect freely. Installing sound absorbers on the ceiling helps to reduce reverberation and creates a more controlled sound environment. In addition to the ceiling, corners and walls are important areas for sound absorption, especially if the room has many hard surfaces such as concrete, glass, or wood.

Sound absorption in the ceiling – the most effective location

Installing sound absorbers on the ceiling is one of the most effective measures for reducing sound reflections and creating a controlled sound environment. There are several different installation methods depending on the conditions of the room and the desired aesthetics. Ceiling mounting with brackets is a common solution where sound absorbers are attached directly to the ceiling, either flush-mounted or with a small distance to improve sound absorption capacity. An alternative is diagonal mounting, where absorbers are placed between the ceiling and the upper part of the wall. This method is particularly effective for absorbing low-frequency sound waves, which often accumulate in these areas. For even better sound absorption, sound absorbers can be suspended from the ceiling with wires. The lower the absorbers are placed, the more effective the sound absorption, as they capture sound waves from multiple directions. Another effective method is vertically suspended absorbers, where sound-absorbing panels hang freely in the room. This is a very effective solution for reducing reverberation and creating more balanced acoustics. In environments where sound absorbers are exposed to wear and tear or risk of damage, such as industrial or public environments, wire baskets can be used. These protect the sound absorbers while providing effective sound absorption.

Corner absorbers – optimal for handling low-frequency sound

Sound absorbers placed in corners, also known as bass traps or corner absorbers, are particularly effective at handling low-frequency sound waves. Since corners are often areas where sound is reflected and collected, a correctly placed bass trap can reduce resonance and create a more balanced sound environment. Bass traps are not only effective but also space-saving, as they are placed in areas that are otherwise rarely used. For rooms with severe bass problems, such as music studios and cinemas, corner absorbers are a necessary measure to achieve optimal acoustics.

Sound absorbers on walls – improve the sound environment and reduce reflections

Wall-mounted sound absorbers are one of the most flexible solutions for reducing reverberation and creating a quieter and more comfortable sound environment. There are several mounting options depending on the needs of the room and aesthetic preferences. For traditional mounting, brackets can be used to attach the absorbers directly to the wall. For a more discreet installation, hidden mounting brackets can be used, providing a seamless and stylish finish. Another practical solution is to use Velcro strips, which make it easy to adjust or replace absorbers as needed. In some environments, such as industrial premises or public spaces, sound absorbers can be placed in wire baskets and screwed to the wall. This provides extra protection and prevents the absorbers from being damaged or exposed to wear and tear. To maximize the effect of wall-mounted sound absorbers, they should be placed on strategic surfaces where sound is most reflected. This includes areas close to sound sources, such as speakers and workstations, as well as parallel walls where sound waves easily bounce back and forth.

Strategic placement for maximum effect

By placing sound absorbers on ceilings, walls, and in corners, you can optimize the sound environment and reduce disruptive reverberation. The ceiling is one of the most effective places to start, as it is often a large reflective surface that can contribute to long reverberation times. Wall-mounted absorbers help to dampen sound reflections and improve acoustics, while corner absorbers are one of the best solutions for dealing with low-frequency sound.

By choosing the right mounting method and placing the absorbers in strategic locations, you can create a more balanced and comfortable sound environment, whether in an office, studio, public space, or private home.

Did you know that..

A room can have perfect sound insulation but still sound bad? Many people believe that if no sound gets in or out, the acoustics are good – but the reverberation time, i.e. how long the sound bounces around the room, can be the real culprit behind an unbalanced sound environment.

The reverberation time is affected not only by the size of the room, but also by its shape and the materials it contains. A small room with hard surfaces can have a longer reverberation time than a larger room with textiles and furniture. This is because sound waves that are not absorbed continue to reflect back and forth, creating a metallic, echoing sound.

You can calculate the reverberation time using a simple formula! Sabine's formula, which is used in acoustic calculations, shows that the reverberation time (RT60) depends on the volume of the room and the amount of sound-absorbing material. The more sound-absorbing surfaces, the shorter the reverberation time – but too much damping can instead make the room "dead" and unnaturally quiet.

So if you find that the sound in a room feels uncomfortable, keep in mind that it's not always about reducing the sound level – sometimes it's the reverberation that needs to be controlled. And the right placement of absorbers can make all the difference!