"Rip apart the ceiling? Have you not heard of an "attic"? "

Yes, have you heard of common sense? From the question posed, it
seemed obvious to me that he wouldn't be asking questions related to
what to put between 2 joists 10 inchs apart, if he could get access to
it from above. He even mentioned that the std spreader bars, which are
used for old work where you don't have access, were too long to fit.
Many installs, like on a first floor of a two story home, or from a
cathedral ceiling don't have an attice. Get it now?