I would post photos, but can't figure that out.
I am using a 12" sub in an sealed box. It can be plugged in inside or outside the RV. The inside is used to add bass to the interior speakers while watching a movie, or a video game. Outside sub location is for sound quality. I am planning on purchasing 2 15" 250w at 4 ohm subs to install into a speaker box i currently own. The box is currently configured with 2 channels at 100w each with 100w woofers and cone tweeters. In the new configuration, I would have the 5 channel amp send handle the subs paralleled (2 ohm) and the cone tweeters as the rear L R channels.
The existing sub can be stored in my wardrobe when not in use. I am also using 4 75w kicker outdoor speakers. The kickers are designed for outdoor use, the sub is not.