Well, don’t overcomplicate it. Just get the UMIK-1 and maybe Amazon Basics microphone stand, where you can get it stably where you need to measure. Whatever stand comes with UMIK-1 is tiny to the point of being completely useless, in my opinion. I also do not use the included wind screen on the mic – maybe it would be good idea to do that, if you were to use it for a speaking microphone or outdoors, but I don’t do that. The calibration files are measured without the wind screen on.

I use the 90deg calibration file and I point the mic upwards when I measure. This is somewhat an arbitrary choice, but that way I can do left and right measurements without having to change the mic orientation towards the speaker at near field, I guess. In truth, I mostly do it like this because Genelec’s microphone is also used in vertical orientation and I think it likely more fairly captures the reflective ambience of the room, as even backwall reflections are going to get measured at close to their full strength, rather than being diminished by the microphone’s lack of sensitivity to sounds coming from directly behind it. At least for my unit, the calibration values are also 2-3 dB smaller in the 90 deg file for most of the audible band, so the file is also barely needed at all, which I like.

Ultimately, all you want to know is the frequency response, distortion, group delay, reverb etc. characteristics of your total system so you know where you stand. You don’t really have to work out what your audio interface’s capabilities are first, or whatever that guy is doing. I think basic 512k or 1M sample sweeps will be fine. Label your measurements so you remember whether it was left, right or both together, then apply some smoothing and use the All SPL view to check how the tonality goes for these 3 cases, to get started.

I also don’t use earspiltting sound levels – 70-80 dBSPL is fine by me. It’s enough to see the sweep. For harmonic distortion measurements, you’ll get proprtionally more distortion the louder you go, and I guess minimum of 80 dBSPL is good to check that things are working and nothing is rattling in the room.