Razer Megalodon USB headphones. Asus P8P67 LE motherboard 8.1 surround sound using Reaktek audio with latest drivers. Headphones show in device manager\audio\. Configured sound settings to 7.1 audio. There is no sound through the headset when running the test sound. The volume control dialogue box shows audio levels are being produced (green level indicator moves up and down). Any suggestions would be appreciated.