Also, there is no need to solder...just a jewler's screwdriver to loosen
the tiny screws in the mic. I also had to bore out the holes on the new
electret mic's to fit the bushing on the David Clark mic boom. Be careful if
you are using a hand drill, as it's really easy to crack the mic assy...As
far as the impedence issue, I really don't know, but I have flown with it
for about 5 hours now in a Cessna 172 and I have not noticed any problems so
far.