Glad you found it helpful.

The channel routing I described in the video is taken directly from page 105 in the R5C's manual (PDF version). It's been my experience, that the manual is correct and the camera route signals as described. However, if you're seeing something different than that, you'd have to ask Canon why. As for seeing a stereo track in Premiere... The only time the R5C records a stereo audio file is when it's in 2 channel AAC mode. In LPCM mode, the camera records 4 mono tracks and you have to tell you editing software to treat them as stereo. I haven't used Premiere for years, but I don't think it should be reorganizing the track structure, or presenting it any differently than it is in the files. So to that end, I'm not exactly sure what's going on there. Also, as far as I know, Rode doesn't have any mics that implement Canon's multi-function shoe. Just putting any mic in the camera's hotshoe doesn't change the routing order or how it's connected. The mic/AIF (specifically Canon's DM-E1D mic, or Tascam's CA-XLR2d-C audio interface) must connect through the pins in the front of the hotshoe for it to be a multi-function shoe device and get routed that way.

@@PointsInFocus I looked back at the footage, and I was incorrect. I was looking at the C70 footage. The R5C footage does reflect what you reported. 1-2 are the 3.5" mic input, and 3-4 does seem to be the internal mic.

I guess I could sell my boom mic and buy the canon brand one that works directly though the shoe, but is there a solution with the mic I currently have? or can it only record max 2 channels through the 3.5 Input regardless

I'm assuming that your Sarmonic wireless system outputs one mic puts each mid on each of the stereo channels. So one goes to left, one goes to right. If so, then you won't be able to use a simple passive cable to combine the output from that and your shotgun mic, you will need a mixer of some sort. The best option, in my opinion, at lest if you're serious about good quality audio, would be to get a proper 3-6 channel audio recorder and use that to record all of your audio. Something like a SoundDevices MixPre-3 II or a Zoom F6 would be idea, but you can of course go with something less expensive. Run everything into that, and either a time code cable back to the R5C or an attenuated patch from the recorders line out so you have good sync sound on the camera. Then use the audio sync function in your NLE (Resolve/Premiere Pro, etc.) to sync the good sound up in post. This will give you the most flexibility, and best possible quality audio. Barring that, you can get 2 more inputs for the R5C with a Tascam CA-XLR2d-C. This uses the multi-function shoe and provides a 24-bit pro level audio interface with 2 XLR/TRS combo jacks (with phantom power) and a 3.5mm (1/8") TRS unbalanced input jack; though you can only use one of the two at a time. You can use this in conjunction with the camera's 3.5mm mic in to record 4 channels independently. The CA-XLR2ds also have a mount for mic if you want to use a standard shotgun mic on camera. As for selling your Sennheiser shotgun mic and replacing it with a Canon DM-E1D... Keep in mind you can't take the Canon off camera. There's no provision for the extending the multi-function shoe connection and there's no 3.5mm option on that mic. All things considered, I don't think that mic is a great solution for most users. It might be ideal for a journalist with an R3 that doesn't want any stray cables, but for everyone else it's quite limiting in the long run.

Put simply, you can't. One of the odd limitations of the R5C is that you cannot turn off, or at least stop it from recording, unneeded audio channels. It always records 4 in PCM mode, and a stereo mix down to 2 channels in AAC mode.

@@PointsInFocus thank you for your quick reply

The only thing you'd have to do in the menus is set the recording levels. Otherwise, it will automatically start recording the external mic when it detects one is plugged in.

@@PointsInFocus Thank you for your fast reply!