I have a home music studio. A new iMac as my primary audio source. I need volume and power for practicing. I currently have a Yamaha RXV479 av system with sub, center and 4 satellite speakers in the ceiling. I also own 4 Polk towers. I want to add in the towers, but obviously there are no more speaker connections. I tried a high end speaker switching box, but it seemed to rob power. A 7.2 av receiver is going to be 2 speaker connections short, plus I don't have a tv for set up. I tried a Denon, but connection to the Mac with cdmi didn't support video, so I couldn't even access the set up menu. My question: would the easiest solution be a 4 channel audio receiver with the towers connected, the current system as is, and just split the 3.5mm 1/8th audio cable from headphones out to both receivers aux in, or connect both receivers together hdmi out to hdmi in? Or am way off base here? Also in the past trying to make an aggregate device between Bose 5.1 everyday computer speakers and the existing Yamaha didn't work due to clocking issues. They never matched up, so I suspect an airplay connection to a new receiver for the towers would have the same issue. Any help would be appreciated.