I have the newest Sonos amp powering 6 Sonance Satellite speakers around my pool. I have an outdoor projector I would like to occasionally use and was hoping I could use the RCA inputs to connect for sound. My projector has the headphone outlet that came with an adapter that splits from the small (3.5 I think) output on the back of the projector to the red and white RCA plugs. I plugged those directly into the red/white RCA inputs on the Sonos Amp and tried to use the "line-In" option from my Sonos app on my phone, but am getting no sound. Is there a way for me to do this?