Additional Information For Helicopter Use Of The Hmec 322 Headset - Sennheiser HD400 Instructions For Use Manual

Additional information for helicopter use of the HMEC 322 headset

The polarity of the microphone connection in helicopters is not standardized. If the
microphone of your headset does not work with the existing polarity, you can reverse the
polarity on the headset by simply rotating the microphone module. To do so, please
proceed as follows:
1. Pull the wind screen from the microphone.
2. Loosen the screws by approx. half a turn.
3. Pull the microphone module from the boom-arm.
4. Rotate the microphone module by 180 .
5. Put the rotated microphone module back into the boom-arm.
6. Now tighten the screws from the other side.
7. Slide the windscreen over the microphone.
Rotating the microphone module does not change its acoustic properties. Due to its noise-
compensating pick-up pattern, the microphone can be used from either side.
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