Need advice on my brothers set up

[angel.d's_hoe]

Ok so here's the deal this set up is my old set up. Going thru some hard times so my brother bought it off me to help me out with some legal custody stuff I need to take care of, anyways..... 

 

The set up I sold to him was two 12" L7's in a q bomb ported box. Don't remember the specs on the box. And also sold with it a 1200.1 watt fosgate prime amp. 

The subs are 2 ohm dvc, they're rated at 750rms each so together can take I'm assuming right under 1500. The amp at 2 ohms states that it pushes 800 rms so with no hard math that's obviously 400 per sub. My brother went and found another fosgate 1200.1, for 70 bucks couldn't pass it up.

 

Now his plan is to put one amp per sub, the amps aren't strappable so the plan is the wire each sub to 1 ohm, and obviously 1 amp per sub these amps i think are putting out more them 1200 at 1 ohm haven't seen am amp test on this model but I know Steve did and amp test on a 750.1 prime I think that pushed more... 

 

How do we know where to set the gain without blowing these things. That's were we're stumped... Lol 

We know a little but not to much... 

 

Hope this is the right sections to post.

 

I went to a few audio shops around the area but they won't give out any kind of advice at all they're money for everything. And I don't know bass heads around here at all.

[ShadeTreeMechanic]

Ideally the gain would be set with a DD1 or an oscope . Then the amps would be gain matched with the subs disconnected and measuring the output with a volt meter to set them the same. More specifically, once the max clean output for each amp is found, then the higher voltage amp would be turned down to match the lower one.