Yeah if you want the same audio stream for all speakers it’s probably easier, but sounds like you’ll need some more equipment. If you had photos of the in wall RCA might help, since it’s 9 rooms are there 18 RCA hookups in wall? Feel like you’d almost need something like this but I’m no expert https://www.amazon.com/Dayton-Audio-MA1240a-Multi-Zone-Amplifier/dp/B003DKVZHQ/ref=sr_1_6?keywords=Whole+House+Audio+Amplifier&qid=1685299388&sr=8-6