Audio setup can be a little tricky. There are four ways to record audio with the C100: with the internal microphone, with the microphones built into the handle, using external microphones plugged into the XLR jacks on the handle, or using an external microphone plugged into the 3.5mm jack on the camera body. (We’re not going to talk about that last one since we don’t use any microphones that plug into a 3.5mm jack.)
The internal mic
Recording to the internal microphone is easy: don’t connect the handle and press record. That’s it. The sound will be terrible but it will at least give you a “scratch track” to help you sync good sound later, or even to use as a reference when you do a foley session.
The handle mic
Recording to the microphone in the handle is pretty easy. Remember to plug the handle cable into the camera!

Now make sure that the switches on the audio interface are set up correctly.

The audio inputs for Ch1 and Ch2 are set to INT (for internal microphone). The input is set to Mic since the microphone does not require phantom power. And here the gain control is set to A for automatic. This way the camera will set the levels automatically. Turning the wheels on top of the interface will not do anything. (You generally only want to do this if you’ve got to leave the camera unattended- while shooting a conference, for instance.)
External mics
If you’re trying to record with a shotgun microphone like the Rode NTG1 you’ve got to set up the audio interface a little differently. First make sure you know which channel you’re plugging into! In the photo below we’re plugging into Channel 1.

Let’s look at how we might choose to set this up on the audio interface.

We’ve switched the gain control from auto (A) to manual (M). Now the wheel on top of the interface will control the gain. Use it to set your voice levels to approximately -12Db! We’ve set the input switch to Mic+48v since the Rode NTG1 is a condenser microphone that requires phantom power.And since this is an external mic, we’ve naturally set the selector switch to EXT.
Notice that we haven’t changed any of the settings on the CH2 side of the interface. This way we’ll record a backup track from the microphone on the handle which could come in handy if we end up with any clipping on the shotgun mic.
As long as the interface is configured correctly you should be able to see the levels moving around on the monitor screen. You can give the shotgun a gentle tap to make sure its connected. You should hear it loud clear and you should see a spike on the CH1 meter.
If you still can’t hear it though, there might be a problem with how your audio output is configured. Hit menu and navigate to the little musical note icon, then select audio output. You should see a screen like the one below:

“Monitor Channels” determines what you’re hearing through the headphones. If you’ve got a shotgun on CH1 and the internal handle mic on CH2, then these settings will give you the shotgun mic in your left ear and the handle mic in the right. If monitor output was set to CH1/CH1, then you would ONLY hear the shotgun mic. If it was set to CH2/CH2 then you would ONLY hear the handle mic.Make sure it’s set to what you want to be listening to! And make sure that the Headphone Volume isn’t set to 0!