eggyhustles

Can i hook 2 recievers up to one source? i tried using 2 sets of rca red and whites...2 sets of headphone to rca y plugs...and on the ipod i had a headphone y splitter.. when i would have one reciever hooked up sound came through both speakers..but when i added the other reciever sound would only come through one side...is there any extra wires i need? any help would be appreciated thanks