The Sennheiser's FAQ has been done to assist you in the troubleshooting.

Choose one of the following topics:

ADN Conference System
Aviation
Battery issues
Other
Technical Services
TV Listening Systems
Wireless Headphones
Wireless Microphones

1. Why am I not getting enough audio/volume output?
   
2. When the transmitter is turned off, I get a loud static noise from my loud speakers.
   
3. My Evolution Wireless doesn't have any range, if I move greater than 10 feet away from the receiver, it mutes.
   
4. I can't get enough output from my Evolution Wireless, what could be wrong?
   
5. My system has drop outs/poor range/mutes. What’s wrong?
   

1. Why am I not getting enough audio/volume output?
   Check the microphone sensitivity setting on the transmitter, it may be set too low (see owner’s manual, page 70).
2. When the transmitter is turned off, I get a loud static noise from my loud speakers.
   The squelch threshold setting may be set to low or off "0dB". Increase the setting to 5-15dB (see owner’s manual, page 71).
3. My Evolution Wireless doesn't have any range, if I move greater than 10 feet away from the receiver, it mutes.
   You have adjusted your squelch level too high, it should be no higher than 05 or 10. If a higher squelch level is required, it means that you are operating on an active TV channel.
4. I can't get enough output from my Evolution Wireless, what could be wrong?
   The sensitivity adjustment on the transmitter is adjusted too low, it is factory set at "-30 dB". Follow the directions in your owner's manual and readjust.
5. My system has drop outs/poor range/mutes. What’s wrong?
   The squelch threshold may be set to high (20 to 40dB). Typical setting is 5 to 15 dB, any higher will reduce range (see owner’s manual, page 71).