My apologies in advance for being a newbie and probably asking a dumb question, but... How would you go about hooking up more than one audio source to one audio output and be able to have all the sources playing at the same time? In other words... i know you can hookup many audio sources to a reciever all at once, but you have to switch between them--you have to choose which source to use. I want to be able to use more than one of them at once. Is this a feature I should be looking for in a reciever? Are there Y adapters for combining two audio sources? Any help would be greatly appreciated!