So I had an old HK receiver that I am looking to upgrade. I've done some research and have made some progress but I am thoroughly confused. I've looked at the Denon, Onkyo, HK and Yamaha RX-V 575. Here is what I know I would like. 5.1 or 7.1 is fine. 3d/4k passthrough Good sound for medium sized room 15ftx15ft ethernet connectivity (wifi isn't mandatory as my router is right next to my home TV Center.) Something easy to use iPhone connection of some sort USB, ETC. 2nd zone isn't mandatory but of course would be nice for outdoor speakers. I have netflix on my blu ray player so that's not mandatory. I have music on my (mac) that would be nice to stream but I can use a Apple TV Box Where I'm confused is about wireless speakers and any other cool feature I may need that I'm not aware of. First how do wireless speakers work? Is it built into the speakers or does the receiver have to have a specific feature. Thanks in advance for your help.