Been wrestling with this too. Gotta get the 1K watts out of this thing and I have two 8-ohm cabs. Assuming the domestic version with no Speakon connectors, I was told...
1. Wire 12g wire to a dual banana plug...the 1/4" or Speakon connector on the other end goes to cab #1.
2. Wire 12g wire to a second dual banana plug...the 1/4" or Speakon connector on the other end goes to cab #2.
3. Piggyback the banana plugs into the two RED monobridge outputs on the back of the amp.
3a....Dual banana plugs have a small flag on one side of the plug. Convention calls for wiring the ground (black) to this side of the twin-pronged plug. Make sure this is wired AND inserted correctly...both flags on the same side and plugged into the negative terminal.
4. Push the mono/stereo button *** IN *** so you're now running monobridged.
5. The bi-amp/full range button has to be *** OUT ***, in Full Range mode.
This should provide the 4-ohm load in monobridged mode driving both cabs. Unfortunately, this will not get highs and lows separated to the two cabs. I believe the only way to do that is in stereo/bi-amped mode so the crossover knob on the front can control that feature. Problem is that you can only get 500W output at 2-ohms in this mode. Almost positive monobridged mode was meant for nothing but sheer power for the full range 810e cab...maybe the 410HLF too.
PS: Gotta be 12g wire (well, maybe 14)...regular speaker wire cannot handle the 1,000 watts.
PPS: The Ampeg techs are available at
[email protected]