Hello, I hope someone can help me. Since upgrading to El Capitain, my Klipsch 2.1 USB dongle is not recognized. Worked perfectly in Leopard, Snow leopard, Mountain Lion and Yosemite. I even did a re-install of the OS (El Capitain). I tested the Klipsch USB Transmitter on another USB port on another devise and it worked (blinking green LED light). On Apple's end I was told that I need to downgrade to Yosemite by taking my iMac to an Apple store. On Klipsch's end, the USB Transmitter is a simple Plug & Play and requires no software, firmware ect. so theoretically it should work. It doesn't. The way music sounds to me is important and without my speakers working, it feels like a huge void. Any help would be greatly appreciated! Thanks!