Anyone think bad idea sonically to mix one dedicated outlet for left monoblock amp and left sub...I have REL set at low output and a low crossover so sub are very modestly involved.Well, to give a highly technical and esoteric answer I would say that if it sounds good it is good :-)
BTW, assuming you are connecting the sub inputs at speaker level, as you no doubt realize (but I'll mention just to be sure) the black wire from each sub should be connected to the white signal ground terminal on the rear of the corresponding amp. With the red and yellow wires being connected to a positive output terminal of the amp.
Regards,
-- Al