I used to be in charge of adjusting an older system (at church - I bet it was expensive when new) .. but I had a hard time with just one row of controls. I concluded the wavelengths would look like a wave, even if you get a couple of them, some adjustment were screw-driver on the back so I did not touch those (gain or squelch?). I used to center all the outputs, turn the sound down and shut off the feedback points as I raised the sound and build the waves from there. The tone was a real problem and then bringing in other mics - they could be different so the compromise setting was really not great .. some plugged in mics, others were via the wireless box. I needed this video back then to understand what I was listening for with each control. It takes almost like using "the force" to have the ear to know which control is the problem.
even though I don't understand what you're saying but just hearing your voice makes me feel happy and and it feels like I understand what you're saying ❤☺☺😁