It seems weird that people are referring to the extreme peak in response as a good thing because sensitivity goes up. some may think this, I do not. I dont want that massive peak in the response.
In short the posts are saying that having the Low freq filter on channel 2 causes a massive peak in output at ~30hz because the 2nd channel is inverted and thus the cut becomes a boost in the signal. This does increase sensitivity as its outputting more per input then before, but it also creates a huge spike in output around a specific freq.
It did not work out for me anyway. Something went unstable with it set up like that, the sub was making long winded fart sounds that slowly withered away after 20 seconds or so. Then a new LFE low noise would come on, and start it all over again.
So it is back to the normal, standard configuration.