Acoustic

acoustique

Acoustic

Our objective

To follow our customers in the choice of an acoustic solution matching their daily using and reaching their expectation of a global acoustic comfort.

How ?

  • Thanks to the understanding of the acoustic behaviour of our different fabrics (refer to pdf acoustic tests)
  • Experiences on real cases.
  • Close partnerships with customers  experts in acoustic

The fabric like any other material, has specific acoustic behaviours which will vary in accordance to its implementation and to its surroundings. So it is important to select its fabric, not only by itself but also by taking into account the different constraints of its surroundings, of its users and of course the acoustic comfort that we expect to reach.  For instance, a classroom will not be acoustically treated in the same way as a theater, a cinema room or a brewery restaurant.

It is so relevant not to select the fabric only on the basis of its alpha w or NRC coefficient. These coefficients are an average of several acoustic absorption results measured on a large frequency band (from the lowest audible sounds to the highest ones). All of these measured in a normalized configuration which is consequently ,most of the time, different from the real case. So an acoustic solution has to be defined on the basis of precise specifications for which Sotexpro can support you by offering a pesronnalized following through its experts network.

Real cases done with a partner

salle des fêtes acoustique
salle des fêtes acoustique
Salle-des-fêtes-Saint-symphorien-de-Lay-05

Ballroom - Saint-Symphorien-de-Lay (42), France
Ballroom : a municipal team fully satisfied

Ballroom - Saint-Symphorien-de-Lay (42), France
Ballroom : a municipal team fully satisfied

Ballroom - Saint-Symphorien-de-Lay (42), France
Ballroom : a municipal team fully satisfied

Rstaurant scolaire Panissières (42)

School restaurant - Panissières (42), France
School restaurant : acoustic reduction measured between 5 and 8 decibels. A gain of 3 decibel refers to a 50% reduction of the acoustic energy.

School restaurant - Panissières (42), France
School restaurant : acoustic reduction measured between 5 and 8 decibels. A gain of 3 decibel refers to a 50% reduction of the acoustic energy.

School restaurant - Panissières (42), France
School restaurant : acoustic reduction measured between 5 and 8 decibels. A gain of 3 decibel refers to a 50% reduction of the acoustic energy.

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Salle-des-fêtes-Saint-symphorien-de-Lay-05
Rstaurant scolaire Panissières (42)
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Definition of the absorption coefficient

Acoustic performance is assessed using two coefficients, αw and NRC, which measure a material’s sound-absorbing ability. In both cases, they are measured on a scale from 0 to 1, where 0 refers to no absorption and 1 means total absorption.

  • The αw coefficient is calculated in accordance with the ISO 11654 standard, and corresponds to the average alpha coefficients measured by frequency across the One-Third Octave band.
  • The NRC, or noise reduction coefficient, is the average absorption coefficient measured at four frequencies (250, 500, 1000 and 2000 Hz) in accordance with the ASTM C423 standard.

In concrete terms

If the absorption coefficient is equal to 0, then the material does not absorb any noise, instead reflecting it in its entirety (resulting in resonance and discomfort).
If the absorption coefficient is equal to 1, then the material absorbs all of the noise, resulting in improved acoustic comfort.
In short: the closer the coefficient is to 1, the more absorbent the material.

Product absorption classes:

The acoustic absorption class is determined based on the value of the αw coefficient.
There are five absorption categories for products, ranging from A to E:

 

Absorption classes Absorption coefficient
A 0.90 / 0.95 / 1
B 0.80 / 0.85
C 0.60 / 0.65 / 0.70/ 0.75
D 0.30 / 0.35 / 0.40/ 0.45 / 0.50 / 0.55
E 0.15 / 0.20 / 0.25
Unclassified 0.00 / 0.05 / 0.10

Mesurement of sound absorption of fabric

For more information on our acoustic fabrics