Chapter 8: Audio Module, Rev 1.1
2. Once each of the channels has been grouped together, use the RMS values to determine
the highest value received for each channel.
RMS Sub- Interval / RMS Microphone Test Value
a. Mike 1 test – chirp detected on channel 2 – 971.378 (300.967)
a. Mike 1 test – chirp detected on channel 2 – 1081.232 (300.967)
a. Mike 2 test – chirp detected on channel 2 – 998.937 (321.623)
a. Mike 2 test – chirp detected on channel 2 – 1067.232 (321.623)
For Channel 2, the highest RMS value is from mike 2 (321.623)
Using the highest available RMS value, complete the following calculation to obtain the
Detection Threshold:
Highest RMS Value / 0.707 = Threshold for Channel X
321.623 / 0.707 = 454.912
3. Next, note the lowest RMS Sub-Intervals for each channel:
RMS Sub- Interval / RMS Microphone Test Value
a. Mike 1 test – chirp detected on channel 2 – 971.378 (300.967)
a. Mike 1 test – chirp detected on channel 2 – 1081.232 (300.967)
a. Mike 2 test – chirp detected on channel 2 – 998.937 (321.623)
a. Mike 2 test – chirp detected on channel 2 – 1067.232 (321.623)
For Channel 2, the lowest RMS sub-interval is from mike 1 (971.378)
The lowest sub-interval should be higher than the calculated Channel Detection Threshold.
In the above example, because the lowest RMS sub-interval of channel 2 (971.378) is a higher
value than the calculated Channel Detection Threshold (425.696), the calculated value is a valid
Detection Threshold for Channel 2.
If the calculated values do not meet the above-mentioned requirements, it will be necessary to
restart the Detection Threshold calculation process. Remember that the bridge must be quiet
when performing a microphone test, as a noisy bridge will produce undesired results.
VDR-100G3/G3S Installation Manual 06/10/2008
8-36
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