DSP channel summing for subwoofer

[RRitch]

I am working on tuning my system and have a question about input channel summing on my DSP (Dayton DSP-408). I am feeding 2 of the 8 output channels into a Kicker Hideaway HS4610 powered subwoofer. My DSP has 4 inputs coming into it from a PAC LPA2.4 active line output converter. 2 of the LOC outputs are full range and the other 2 I have the LPF enabled and adding slight bass boost to help with the low frequency roll off from the factory head unit. I also disabled the eq settings in FORscan to help flatten what is coming out of the head unit. I am wanting to sum the 2 DSP inputs that have the connections from the LOC that have the LPF and bass boost applied (3 & 4) and output those to the 2 sub channels from the DSP feeding the 2 inputs on the Kicker Hideaway (7 & 8). I know how to link the 2 sub output channels on the DSP and assign both inputs to them to sum the inputs, but what I am not sure about is whether I should set both inputs to 100% or should I set each at 50% (summing to 100%). I have tried both and I definitely get more bass with both at 100%, but it also causes the sub to start clipping even at moderate volume. Based on that I am not sure if I should set the each of the inputs at 50%, or should I set them at 100% and readjust the gain on the Kicker? If either approach is acceptable, what would be the pros and cons of each? Hopefully I am describing this so it makes sense.

 

[RRitch]

Hopefully this diagram makes it more clear how things are connected