My last camper didn't come with exterior speakers. Rather than buy, install weather proof speakers, and run wires to seemingly impossible places in the side wall, I bought two wireless speakers with a range of about 40' and plugged the transmitter into an aux speaker jack inside. It was neat, quick, sounded great and I placed them anywhere I wanted to on the campsite. I use re-chargable batteries. Today there's a variety of choices between battery, bluetooth and 12v.
I sitll use them today sometimes. The Rockwood has outside speakers but I have to turn them up way too loud to hear them 20' away at the camp fire.
2012 F150 F/X 4, 6cyl EcoBoost with Max tow pkg
2013 Rockwood 8280WS 5th wheel
2006 Sunline T1950
2004 T@B T-16