Do I need a new sound card ?

[jlohojo7]

I was just wondering I have an old sound card that came with my pc. I have been playing my music on my xbox which is hooked up to 7.1 sound along with my projector its awesome. My question when it output it via ethernet cable upstairs I only get 2 channel sound. is that bc my sound card do i need to upgrade or is it just bc thats all the ethernet cable can do. I have tried switching the output mode on my receiver but it still just the 2 front speakers.

thanks

jj