On my '98 Coachmen Sanatara, these speakers were mounted from the rear onto the cabinet grills. To get access to them, the partition between the cabinet proper and the speaker area had to be removed. It was held in place by (headless) pin brads, and is removed by prying it off carefully from the framework.
The speakers themselves from the factory were basic cheap Ford car speakers. On mine (and on many others of the era), there was a problem with the mounting screws used on the speakers not having large enough heads and only catching the plastic/fiber surround part of the speaker and not the metal frame. Over time, these two bits separate and the speaker can eventually fall off its mounting, which of course makes it sound a lot worse than originally. (That's not to suggest they're particularly good speakers when new....)
I put the divining panels back with a few
lath screws rather than pin brads. It makes the inside of the cabinet look ever so slightly less finished, but makes for easier access to these areas should that become necessary.
