Spork, I'm wondering about the connections that would hook directly up to the source, I don't know if this would work (partly because the website does not mention GCN and partly because I'm not familiar with the differences in the PS2, XBox, and GCN connections in the back). However, I do know that for ProLogic2, the decoder takes the stereo inputs and changes it to PL2 surround, so if the GCN stereo outs connect into the decoder, it should work fine. Do a little checking out at your local store, and if it will work, it sounds like a great system, and go for it!