for troubleshooting, i bought some stuff from radio shack. I replaced the short audio cable with gold plated tips, from ifly to lightspeeds, with no help. I tried a new power cord from cig socket to battery, no help. What did make a different, was i plug an a/c power supply into house current, which stepped down to cig plug socket. Then from there into ifly battery. That did clear up the noise. The problem appears to be within the klx 155 radio and ships battery. When I get my 650 installed, I'll have the guy introduce whatever filter he may suggest, to rid of this issue. As for now, I suppose I'll leave the ifly battery as a backup, or deal with the noise. I'm sure I'm not alone. The noise is definetly magnified with anr type headsets.