Measurements were taken by the independent Acoustic agency Decibel, eng. Stanislav Filipov.
They were taken in the empty hall, measuring the pink noise generated by the electroacoustic system of the hall.
The measured signal was generated at LAeq = 90 dB(A) level in order to ensure a homogenous sound field and a good signal/noise ratio. The aim was to exclude the impact of external background noise.
Several measurements of reverberation time (RT60) were taken at different points on the playing fields and the stands.
The following equipment was used for the measurements:
1. Pink noise generator – NTI MR-PRO, software version – v2.3
2. Spectral analyzer NTI XL-2, software version – v3.3, installed software packages – STIPA option and Extended Acoustic Pack.
3. Measuring microphone – NTI M4260, pre-calibrated by the producer – 28.8 mv/Pa

Analysis of Reverberation Time RT60

Comparison of acoustic characteristics of the largest concert halls worldwide

The famous Concert Hall in Munich, Gaseig, with the same volume of 30 000 m3 has RT-60  =1.9 db.
The RT-60 of S.I.2L.A. is better by 0.01 db.


Source: Master Handbook of Acoustics 5th Edition (2009)