ATEIS DIVA8G2 - Manual (Page 185)

System Functionality 185
© 2012 ATEÏS
measurement.
Amplifier monitoring:
The amplifier monitoring used a pilot tone at 18kHz or 20kHz that is adapted to pull out 2 Vrms. By
measuring the output signal of the amplifier and computing it in the DSP, we can adjust the level of
the pilot tone. The adjustment of the pilot tone is related to the amplifier gain and can directly inform
us on the gain value.
The gain variation are measured constantly and compared to a gain references value.
Below, you can find a bloc schematics for Voice amplifier channel.
Note: If the amplifier gain is changed after the reference has been taken, the pilot tone level could
increase dramatically.
Example: the reference is taken with a gain of 1, the pilot tone will be set to 2Vrms. Then if the
amplifier gain is increased to 100, the pilot tone level will be raised to 200Vrms!!!!
To avoid problems, the gain of both Music and Voice amplifier should be set to same value and in
preference to the maximum gain value.
There is three different channel for monitoring: Voice amplifier channel, Music amplifier channel and
VO3 channel.
VO3 is channel that only generate the pilot tone in case no amplifier channel is in used.
Zone Monitoring:
Zone Monitoring is based on three different reference values: Line A, Line B and Line A/B. Reference
for Line A and Line B are Line A and Line B direct impedance measure. Reference Line A/B
correspond to the Line A and B in parallel.
Line A = Za
Line B = Zb
Line A/B = 1/((1/Za) + (1/Zb))
To ensure a high precision measure, for each reference (A, B and B/A) three values are taken.
Example: Line A: VO3 channel, Line A: Voice amp channel and Line A: Music amp channel. In the
references display, the value will change according to channel routed on each zone.
Example: Zone 1 Line A ref: