Yes, you are incorrect. Again, the amp itself does not know how many wires you have connected to it, it only knows the ohm resistance wired to it. That amp he is using is rated at 750w x 1 signal @ 2 ohms. So no matter how many speakers he has wired to that signal, as long as the resistance is 2 ohms, then that amp is suppose to be supplying 750w. This is why you see so many different configurations in subwoofer coil ohms. You see single 4 ohm, 8 ohm, and 2 ohm, or dual voice coil 2 ohm, 4 ohm, 8 ohm, etc. This allows you to be able to wire your speakers to a certain ohm resistance based on the amount of subs/amp you choose. You don't have to have the same number of amplifiers (or multiple channel amplifiers) as you do subwoofers/speakers, you just have to make sure that the amplifier is stable at the ohm load you wire your subs to it. When you referred to bridging the amplifier, that is a multiply channel amplifier that you are essentially making into a monoblock amplifier like what the OP has.