Troldtekt acoustics report
This acoustics report is generated from the data you have entered into the Troldtekt acoustic calculator.
The report’s calculations are intended to reflect the acoustic indoor performance of the room in question and reveal whether the specified requirements regarding room acoustics (reverberation time and/or
absorption area) can be met with the selected materials. The size of the room and the choice of materials are critical for the results.
Troldtekt acoustics report
Reverberation time
Reverberation time is the time, measured in seconds,
that passes between a sound source stopping and the sound
dying out. In a church, the reverberation time is long, i.e. it
takes the sound a long time to die out. On the other
hand, in small rooms with a lot of furniture, curtains and
carpets, the reverberation time is short. More accurately,
the term reverberation time denotes the number of seconds
it takes the sound level to drop 60 dB after the sound source
has ceased.
Sound absorption value
The efficiency of a sound absorbing material is expressed by
means of its sound absorption value. The sound absorption
value is expressed using the Greek letter α (alpha) and alpha
values are measured over a wide frequency range (bass,
mid-range and treble). The sound absorption value not only
depends on the material but also on how the material is
installed.
Absorption and absorption area
The sound absorbing effect of an acoustic material
depends partly on how effective the material is in itself
and partly on how many square metres of the material you
install. The effect is called the absorption and is simply the
product of the sound absorption value and the actual number of square metres of material. If you install 100 square
metres of an acoustic product with a sound absorption
value of 0.6, the absorption will be 100 x 0.6, i.e. 60. The
greater the absorption, the lower the reverberation time in
the room.
Sabine’s formula
Acoustic calculations from Troldtekt A/S are based on
Sabine’s formula. According to this formula, the reverberation time (in seconds) for a room is directly proportional to
the room’s volume (in m3
) divided by the total absorption in
the room (in m2
Sabine, ‘metric sabin’).
Basic data, e.g. the sound absorption value, is based on data from the Danish Building Research Institute’s indoor climate manual, the
company DELTA and the acoustic consultant Jan Voetmann. The results in this report are meant to be indicative only and Troldtekt A/S
cannot be held liable for any losses or damage which may result from use of the calculator.