I don’t know this camera, but in the DV cameras I’ve used, 4-channel recording is stereo. In other words, 1 and 3 are a stereo pair and adjusted with the knob for 1. Similarly, 2 and 4 are adjusted with 2. Also, 4-channel samples 12-bit audio, not 16. I hope someone who knows the hvx 170 will confirm.
Jayasri Hart
HARTFILMS
Los Angeles, USA