So I'm looking into switching from a dedicated bass head to a pre/power amp combo. I'm working with 2 600w 8ohm cabinets so I would like to find a power amp that pushes at least 500w @8 ohms to each cab. Now for example, the QSC gx5 States it can do 500w @8 ohms both channels driven vs 600w @8 ohms single channel driven. My confusion arises with the single & both channel driven. Does that mean 500w per channel, one channel per cabinet? Or perhaps 600w bridged into one 8 ohm cab?