User manual

85
Reverberation Time RT60
Measurements with multiple source and microphone posi-
tions
Room resonances may be applicable at individual measure-
ment positions. Thus perform RT60 measurements at further
positions within the room and average all readings.
Overload Indication
In case the measurement result exceeds the preset measure-
ment range, then limit arrows
indicate this overload condi-
tion.
Possible causes for exceeding measurement ranges are
The measured sound pressure level exceeds the pre-set •
measurement range -> select the next higher measurement
range or reduce the input signal level as applicable.
The input level is near the maximum level of the connected •
NTi Audio measurement microphone.
In case the level cannot be reduced (e.g. using a gun as signal
source) then the overload condition can be skipped by storing
a text-file with the filename “RT60allowOVLD.txt” on the XL2
main directory.
Error Indications
Various error indications are displayed for unsuccessful RT60
measurements. Corrupt cycles can be deleted individually.
These results are then excluded from the average calcula-
tions.
LOW LEVL•
This is the abbreviation of “low test signal level” during the
measurement. Increase the test signal level until the black
level markers exceed the grey level markers in every fre-
quency band. Also, ensure that the level falls below the grey
level markers, otherwise use a RT60 test signal with longer
on/off times.
T>18S •
The measured reverberation time exceeds the time limit of
18 seconds. This is commonly caused by either an incorrect
analyzer range setting or environmental noise. In the first
case, choose another range setting. In the second case, en-
sure that the environmental noise remains constant during
the measurement, and/or SET the level markers again while
the environmental noise is high.