I bought this, http://www.newegg.com/product/produc...82E16882333101. Its made to automatically change to a active device when detected. I bought it to try to use with my HD Radio and XM so I can use it on the only line in port that I have. It automatically switches when using video and plugged into each video port, but if i only use audio, it does not automatically switch.

Is there a way I can trick the unit by connecting something to the video port and then to the HD. So when the HD turns on, it will trigger the video, thus switching the audio?