It really depends on how much distance you have from your receiver/amp? I used 12gauge for my entire system, I bought a 500' roll on Ebay. Many people use 14 or 16, it really depends on how far the cable run will be...?

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