In a case like this, I suppose a professional sound mixer in a recording studio could moonlight his services by getting the sound right in a home theater set-up.
Adjusting all the knobs to get the sound "just right" would be the extent of his work.
Can I print out a fake degree from Full Sail and get in on this side hustle? I have an ear for music, I know what sounds good to me and I know how to adjust the bass and treble. If I need more experience, I'll consult professor You Tube.
I kid, but that does sound like a good idea.
If you have an ear for music and fix one or two set-ups, referrals will have you overwhelmed with no one wanting to see your qualifications. I think anyone can be good at this by checking out a few YouTube tutorials.