Thanks for clarifying that. My last question (I swear) so 4 awg split at d-block with 8 awg to each amp so does this mean I ground both amps with 8 awg? or can I ground them with 4 since the main power wire is 4?

Thanks again. I've been reading forums and browsing every single car audio site for a week! Before this I knew NOTHING about this stuff. Installed my DEH-6900UB a few weeks ago, was surprised to hear how good it sounds on stock speakers alone, then the mission started to connect subs