DK

If your amp has 5 discrete amplifier sections, one for each channel, then you should treat the rears the same as if they are mains. Another thing you need to assess is the volume at which you play video etc. If your wire is too small then you end up pushing your amp which may cause it to overload and trip frequently. Think about it as trying to move the same volume of water through a drinking straw and a vaccuum cleaner hose.

Sean

Exaudio ergo cogito ergo sum