That is the beauty of finally posting something - you inspire folks to correct you!
So - the better answer is to tap into the signal side from the HU and then install a signal sensing switch to trigger the amps.
Actually, the sound that I am getting is pretty excellent. The amp acts as a bass blocker for the midrange keeping it protected from the low signals.
The reason that I guessed about the 800hz was by the sound of the midrange by it's self (not by good sub crossover freqs). There is no way that the midranges go to 120-250hz. Based on the sound that they cut off at, on the bottom end, was why I guessed that number.
Thanks for helping to get to the bottom of this - finally!