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How many sound absorbers do I need?

You've probably already asked yourself how many sound absorbers you need to achieve optimized room acoustics. Take a look at our example calculation and easily calculate the required number of FENNEXT sound absorbers yourself.

Sound absorbers: How much do I need for my room?

The number of sound absorbers you need for your room depends on various factors, such as:

  • the size of the room,
  • the type of surfaces in the room (e.g. floor with tiles vs. carpet),
  • the type and number of furniture used,
  • the already existing acoustic objects (e.g. curtains) and
  • the type of noise occurring in the room.

A general rule of thumb is that for an average room of around 20 to 30 square meters in size, approximately 10 to 20 square meters of sound absorption surface is required to achieve sufficient sound absorption. This corresponds to around 10 to 20 percent of the total area of ​​the room.

In order to better take the individual factors described at the beginning into account when calculating the required quantity, we at FENNEXT recommend the following calculation:

  • If there is slight reverberation, approx. 10% should be
  • With increased reverberation approx. 20% and
  • If there is strong reverberation, around 30% of the wall or ceiling surfaces should be fitted with sound absorbers.

How many sound absorbers you need

Using an example calculation, we would like to show you how you can easily calculate the amount of FENNEXT sound absorbers you need yourself.

Please note: The following calculation assumes that your room should only be acoustically optimized with the help of sound absorbers. Further influencing factors that you can use to adjust the required amount of sound absorbers can be found in the following paragraph.


    1. Initial situation:

      You have a room with 12 square meters of floor space. One side of the room is 4m long, the other side of the room is 3m long. The walls are 2.5m high.

      To place absorbers on the wall, first calculate your wall area . In this case that is [(2 x 4m) + (2 x 3m)] x 2.5m = 35sqm wall area

      Note: The ceiling area is not taken into account in this example. If necessary, you are welcome to do this. In this case, for further calculation you simply use the total area, which results from the wall area plus the ceiling area.

        2. Calculation of the wall area to be equipped:

          If there is slight reverberation, approximately 10% of the wall surface should be equipped with sound absorbers, which corresponds to the following calculation: 35 square meters of wall surface x 0.1 = 3.5 square meters

          If there is increased reverberation, you would equip approx. 20% of the wall surface with absorbers, i.e. 35sqm x 0.2 = 7sqm.

            3. Calculating the number of sound absorbers required:

              But how many FENNEXT sound absorbers do you need? Our hexagon-shaped absorbers each have an area of ​​0.054 square meters . With slight reverberation, which corresponds to a requirement of 3.5 sqm of equipped wall space, you would need around 64 FENNEXT sound absorbers (3.5 sqm / 0.054 sqm = 64.8), with increased reverberation you would need around 129 FENNEXT sound absorbers (7 sqm / 0.054 sqm = 129 ,6).

              Here is an overview of how many sound absorbers are included in our hexagon sets:

              Sound absorbers: optimal number and influencing factors

              The amount of sound absorbers required, which you can calculate using the calculation above, can be individually reduced by taking the following points into account:

              1. You work in your room with various other objects that are acoustically effective (e.g. fabrics, curtains, carpet, couch, ...)
              2. To save your wallet, you can use large and cheaper sound absorbers for the ceiling (unfortunately we do n't have these in our range yet ) - provided that the quality and appearance are not that important to you at this point ;)
              3. You place our sound absorbers as efficiently as possible in the room: This point is generally important in order to achieve optimal sound absorption. However, the ideal position of the absorbers always depends on the respective room situation. It is difficult to give general recommendations in this area. Please take a look at our blog, where we introduce you to methods and tips that can help you find the ideal position for your sound absorbers.

              Our recommendation: gradually optimize the room acoustics

              If you are generally unsure about how many sound absorbers you should get, then proceed step by step when equipping your room and start with a smaller amount of absorbers. Thanks to the modular expandability of our absorbers, you can easily add them gradually as needed. This way you avoid over-optimizing your room acoustically, which can seem artificial and unpleasant. If you have achieved a reverberation time of approx. 0.3s, your room is considered acoustically optimal.

              Please note: The aim of using sound absorbers is to improve the acoustics within the room by optimizing the reverberation time. If you want to isolate the room, i.e. prevent noise from penetrating outside (e.g. because your neighbor doesn't like hearing you play the drums ;)), sound absorbers are not the method of choice here. For more information on the topic, take a look at our blog article about how sound absorbers work . The difference between sound attenuation (sound absorption) and sound insulation (sound insulation) is also discussed there.

              Of course, you can contact us at any time if you have any questions about the optimal number of sound absorbers or your individual room situation. We would be happy to help you find a tailor-made solution for your space.

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