Well, sooner or later, when I get enough money I will be running 2 12"RL-ps off my bx1605D myself. But going to buy a used one from mike later this week, and run 1 in a ported box. ( I CAN't WAIT!!!!) It will be getting 600w each. If running on a stock 12v alt, that hifonics may put out about 800~@1ohm. I have never tested or bench tested any hifonics amps, but reading through many many threads about these amps, it seems that they will do the suggested output only at 14.4v. So mine will probably do about 1100@1ohms and not 1600. As to your question, Mike states that it isn't necessary to send them more then 700w a piece, because full excursion is reached at around 700w. I think sending 400 to the 2 12"s will run them sufficiently, but Don't know about them 15"s =) GL
