Normally you can "daisy chain" one or more subs together as you described, however, I think you have to go from Line In-Line Out-Line In-Line Out-etc....I could be wrong, but I don't think the XLR passes through to the Line Out jacks on the 500

M80s VP180 4xM22ow 4xM3ic EP600 2xEP350
AnthemAVM60 Outlaw7700 EmoA500 Epson5040UB FluanceRT85