XtremeMac has released some very cool speakers over the years, and Tango Air ($300) is a proud new member of the family -- the company's first with AirPlay support for wireless streaming. The stationary unit can be positioned horizontally or vertically and packs five active drivers plus a passive radiator. Four hardware buttons are on the front -- power, volume, and input selection -- while a wireless setup button is located on the back, next to USB,…