actually sorry, jriver audio output should go to whatever your actual output device is, enable wdm and then that device should be set as the default audio device in windows, playback from a browser should automatically route to that device and then the WDM driver will activate to route it through jriver and out to your audio device.
if that isn't happening, it would suggest some other device is taking browser playback, you'd likely need to look in windows sound settings view to see where it's going