The two balanced mono 3.5mm microphone ports on the front of DSMC camera BRAINs are intended for use with a mono mic level signal. If you are using a stereo microphone with a built-in cable, such as the Rode Videomic Pro, you will need to attach a stereo-to-mono adapter in order to receive an audio signal successfully.
The XLR Microphone Cable on RED.com is for balanced inputs (i.e., +/- inputs). It may not work directly plugged into a standard microphone without another cable in between.
To solve this, you could use a 3.5mm stereo breakout cable to connect two (2) microphones (L or R):
You could also use a 3.5mm stereo to XLR breakout cable:
NOTE: when selecting a cable you will need a "breakout" cable and not a "splitter" or "Y" cable. The"splitter" or "Y" cable will simply duplicate the common connector leaving you with the same potential issue.
If you want to record only one (1) single channel on a DSMC2 camera, you will need to use a stereo breakout cable, a stereo microphone, or mono microphone.