Quick question, quicker answer.
 

I have 2 10's in the same box. I was just wondering if it's a problem to make the left sub hooked up to the left channel, and the right one to the right. I guess that doesn't really make sense now that I type it out... I was almost certain you could, but a 'know it all' friend says they need to work together, or something? But bass would be constant/the same left and right, correct? thanks.

Yes you could do that. Just use the nonfader preout on the head unit and both channels are the same.

Correct me if I am wrong guys.

Alright, thanks. But non fader pre out? I just used the sub out / read outputs? Good?

The frequencies will be recorded in mono anyway so yes you can wire the subs in stereo and get the exact same effect/sound.