We had a similar issue with sound in our TC when the AC was running. We don't watch a lot of TV when traveling, but there are times when we want it. We certainly don't want the TV sound to be heard outside the TC. We also don't obsess with quality, but our solution turned out to sound quite good.
The radio in our TC was very poor choice for a mfgr to make (cheap junk) and has no AUX input. Also could not control speakers independently.
I went a much cheaper route than a sound bar or new radio. 2 stereo cables and 2 pairs of computer speakers were $28.
I routed a 1/8" stereo cable from the TV output under the mattress around the camper to the edge of the slide. Found a great little plastic "J" channel molding at Lowe's so most of the cable doesn't show. Then a splitter and stereo cable to the far side of the dinette. The speaker wiring on the near side of the dinette reached directly to the splitter.
I found some very small, fairly good sounding, computer speakers. Power, volume, and bass boost only.
I mounted a pair of speakers above and on each side of each dinette seat allowing each person to adjust the volume to their liking.
The splitter unplugs from the first cable when putting the slide in. If we want to use it with the slide in, I just pull the cable out of the "J" channel temporarily and plug it in.
You have a bit more room in your 1150 so a sound bar mounted in the dinette might be a good way to go.
Good luck,
**edit - I run the speakers with an AC power module but the speakers can be powered by batteries.
Joe and Evelyn