21
Symptom
Possible cause
Solution
Intelligibility of sound
from microphone is poor
Low frequency masking
Poor microphone user
techniques
Turn speech enhancement filter on
Instruct user/reduce speaking distance
Microphone connected,
input LEDs are off
Phantom power not turned on
Input level too low
Microphone needs higher
phantom voltage
Microphone/lead/connectors
faulty
Turn phantom power on
Increase input level/reduce speaking
distance
Use valid microphone or connect a
microphone mixer (amplifier)
Exchange faulty part
Alarm/priority signal is
not clear
Override DIL switch not set to
allow this function
Set DIL switch to correct position
Cannot achieve required
frequency response at
100 Hz
Speech enhancement filter
turned on
Turn speech enhancement filter off
Cannot achieve required
frequency response at
5 kHz
Parametric MLC not set correctly
Frequency dependent losses too
high for parametric compensation
Set Parametric MLC to correct level
Use smaller/multiple loops
