Svantek SV 977D - Page 361

361
SV 977D User Manual - Appendixes
Fig 4. The RT 30 evaluation
E.3. DESCRIPTION OF DECAY CURVE RECORDING IN DIFFERENT MEASUREMENT METHODS
➢ DECAY method
This RT 60 measurement method requires omnidirectional sound source which emits pink noise in
appropriate frequency band. The most critical parameter of the omnidirectional sound source is emitted
sound pressure level as it was mentioned in the beginning of the appendix.
The graphical illustration of the data recording in this method is presented in Figure 5.
Fig 5. Data recording in the decay method of the reverberation time evaluation
t [s]
L
[dB]
t
4
t
1
L
1
L
4
5 dB
noise
margin
linear approximation
t
2
t
3
30 dB
t [s]
L
[dB]
t
e
t
s
L
2
t
trig
10 dB
L
1
registration time
t
off
t
on
L
2
L
3