Stereo Systems How Do I Play Music On 2 Separate Stereo Systems Simultaneously?

How do I play music on 2 separate stereo systems simultaneously? - stereo systems

I have a stereo and speakers in my family room (AV Receiver Yamaha RX-V661) and stereo / Other Speaker System (Sony FM Stereo / FM-AM Receiver STR-D665) is an increasing my bonus room. There is no wire between these two systems. I would also like 2 sets of wireless speakers in my patio and solarium. When I party, I want each of them play the same songs from my PC media server. Is this possible?