I've just retuned everything. For some reason, my headunit clips after volume after 28 knob. It use to clip after 30 but after all the new changes I've made, it's now at 29 and over.
I've taken out the broken PPI P900.4 and put in my old eD Nine.2 (I'm surprise that thing is still working until today. I got it back in 2007 or so) and tuned everything at 0db test tone.
The DC5K is tuned at 0dB to output about 4000 watts total. For shit and giggles, I played the 40hz -5dB track to see how much power I'd be outputting for the lowest songs and it was only outputting about 2000 watt total. I just did a 10 minute drive on full tilt with the new tuned settings and the voltage averages about 12.9V. I guess the XP3000 helps a lot haha.
Once I get my new Alt in I'll probably retune it at 40 hz @ -5dB test tone instead of a 0dB tone (unless all the DC Audio people here recommend I stick with the 0dB tone).
All in all, I'm satisfied with the new equipment
Note: The amp and dustcap were just a little warm and hot so I think I'm good so far.