I have purchased the Rode Link Lavalier microphone. I am able to use it but I am not able to monitor audio while it is in use. It connects to the headphone jack on my 6D but I do not know how I would listen to the audio coming through while it is hooked in. Would a splitter solve this issue or would that interrupt the Rode Link feed into the camera?
DSLRs are great. Their biggest pitfall IMO is their lack of any way to monitor quality audio aside from the onscreen bars.
I would say get a small, internally powered mixer (there are a few that attach to the threads on the bottom of the camera, then have their own threads for attachment to say, a tripod), because the good ones will have monitoring ports, as well as a variety of other inputs, including XLR.