Note: the audio levels are not set to automatic; there's no automatic level control at all in an HVX200. Channels 3 & 4 are set to a fixed gain level, which is equivalent to putting the potentiometers at top dead center.
"automatic" was probably not the right term....however, there is no way to control the levels on Track 3&4....i was assuming too that the internal mic has a limiter...
To clarify, the dials always control channels 1 & 2, but channels 1 & 2 can be either the internal mikes or the XLR inputs depending on how you have the input select set.