Well, I can see the question. I have a setup from Mackie 1st generation HR824 w/sub. These can be set to THX standard which, I believe is a motion picture audio standard. So I never felt with 'is the sub too loud" cuz it was matching a standard and they mixes translated well.
I only used the sub towards the end of the mix to check the sub harmonics that your can't KNOW for sure without experience.
Having said that, my sub blew up two years ago and, while I plan in getting it repaired maybe this year, it hasn't been 1st on the list to send resources too for the list two years. ?