I was just wondering if anybody had used a zone2 amping and passed the subwoofer preamp signal back into the receiver to supply the amplification for a passive subwoofer. This would allow the use of the receivers cutoff freq control, but would it "delay" the music or movie too much. I know I should just by a plate amp or use my old receiver but it is such a good Rube Goldberg solution.
Are you presently using all 7 speaker terminal outputs? Do you have a powered sub already?
I don't know why you don't just use the speaker terminal that you would have to connect to the sub anyway without all the pre-in-out patching. Can't you define the crossover per speaker output on the 3803? Why all the wrangling to do something that seems fairly easy to do even with out an external amp.