Nickword is correct in terms of terminology. Vertical bi-amping is using one stereo amp per channel and wiring one channel of that amp to the tweeter terminal and one to the woof/mid terminal. Obviously, the amps have to be identical in either case (unless you have an active x-over and go horizontal). Two DNA Rev A amps is a great set up with 3A sigs, but if you have the 2WQ sub(s), then I would recommend the 0.5 and spend the extra $ to go to an A+/Platinum upgrade. The idea of vertical bi-amping is to reduce cross talk and increase separation. If you are using one monoblock per channel, you cannot bi-amp, as you only have 2 channels of amplification total. Of course to bi-amp, you need 2 pairs of speaker cables.