Carl, can you realy hear to 20kHz? Have you been tested by a medical professional or audiologist that does hearing exams. I used to have pretty good hearing, enough that the old 19 kHz Admeco ultrasonic motion detectors that were used in the late 60's and early seventites would just about instantly give me a headache when they got turned on. Of course, I was only 18-20 at the time, I always thought my hearing was excellent. So, give yourself a test. Get a good pair of headphones, and an HP 3325 signal generator (or equivalent) and sweep through the range to see where your hearing falls off. Don't use extreme power levels, even if your can't hear it, it could cause warming of the soft ear tissues. This gave me a good wake up call, I'm 48 and little over 16 kHz is about it, sadly enough. Well, thanks for the conversation. /Paul
