I have a good Yamaha 5.1 surround system based on the RX-V685 Receiver, NS-SW300 Subwoofer, NS-P350 Front & Centre speakers and Musiccast 20 rears. (I had some issues with the Musiccast link a few months ago, but that's now completely sorted). But as I have a 4K TV, 4K BD player and several UHD...