Hey, Iffy. I just got back from trying 4K out at my local old park and found that it quickly drove me nuts with all the chirping. Everything was chirping with a high tone. I tried sensitivity ranging from 18-22, recovery speeds from 3-5... nothing seemed to matter. I buried a 4" dime and found that I actually had to listen for the average tone to DROP. It did ring in clearly at 25-28 VDI but I could not live with the constant chirps.
I told a friend about it and she was wondering if you had maybe tweaked your tone breaks. I said that I doubted it, but that I would ask. So, I'm asking.