If he is using all his available power from his electrical system, it doesn't matter if he was usind 2 3000ds, the output of the amp can only be wat the electrical system can supply.
I would also assume because the OP was using 2 AQ amps and his voltage drop was less on the AQsm that he was running them under a lighter load than the single SAZ3000d is seeing. therefore he was not utilizing the AQ amps to their fullest, and I am assuming he is using the SAZ300d at aleast 1ohm if not lower (don't let Jacob know if it is lower)