Have 2 4500's. AOA is calibrated and display on the 4500 works great. I have no audio "angle angle push" at 115% of stall. The display graphic is correct at 115% of stall, but no audio. The audio is set to "on" in the AOA calibration page. The volume is up - I hear other messages. It plays when on test audio in calibration page. My software is S8.622-MV15 (Feb 10 2012). Thanks - Bob Kurrle