That was fun call. A couple quotes.
"I have been doing this 14 years"
"those subs can take balanced or unbalanced, they have an XLR and 1/4" "
"I'll turn up the levels when I calibrate it"
It's obvious he has a fundamental lack of knowledge on the subject, and that he didn't like be called out on it.
I am not the owner/client, I just happen to work here and see what he did wrong, my hands are tied on what I can actually make him do.