SH: you hit the nail on the head earlier...it really IS harder to write it in logical order than it is to visualize.

i'll try, nevertheless.

bass below crossover (60hz in your case), summed with lfe (bass below 120hz) and bass to mains (as low as the program), equals double bass. if you low pass that combined signal to your subs at 60hz, your subs get the bass info below 60hz from the L, R, SL, SR, center and lfe signals.

there is most certainly a phase issue there, but, if you don't hear one, that isn't a big problem (though i can't imagine what 2 18's driven by 1,000 watts sounds like either way...and, by the way, on that subject...too cool). the main problem is that you have double bass in the subs. it ain't a bad thing either, but you have trained ears...you would hear a definite difference with full range to the mains and only lfe in the subs.

and btw, you don't have dbl bass in stereo with your setup, in fact you have the ultimate stereo setup....must sound very good.