Harman Kardon knows this well enough to ship its AVR 2700 and AVR 3700 receivers, both of which carry 4K passthrough and upscaling on their eight HDMI ports as a matter of course. The two also support AirPlay streaming alongside more commonplace DLNA media sharing and offer remote control mobile apps. Home theater futureproofers mostly have to decide on audio channels and network support before they buy: the $800 AVR 2700 produces 7.1-channel surround and sticks to Ethernet alone for networking, while the $996 AVR 3700
