My 19H didn't have outdoor speakers so I purchased a pair from Amazon and mounted them to a bracket I bring outside when we camp. I pulled the radio out, and ran the wires to the Speaker B connections. It works fine.
Model X19H Expandable
GMC Sierra Pick up
Been a camper since I was a kid, and that was a long time ago :)
From pup tents with no floors, to tents with floors and flies, to a pop up, to the expandable.