Sennheiser SK 5012 Notice D'emploi page 31

Adjusting the sensitivity
Use the 6-step sensitivity
switch ( ) to adapt the
GAIN
gain of the microphone input
to the expected sound levels.
In practice, the following settings have proved their worth for
adjusting the sensitivity:
Position 1 = high-frequency, loud audio material with many
plosives
Position 2,3 = loud voices, vocals (close-miking)
SK 5012 - 31