Hey guys, I pm'd a memberr here that's been helping me with my martysubs and this is what he said about running two d2's with the 6000dsp....thought it might be helpful for anyone seeing this thread down the road.
"You'll want to wire the voice coils of the sub in series for a 4 ohm load. Then you'll wire up your speakon cables positive to +1 and negative to -1. Each sub will be on its own channel so you'll want to set the limiter to ~1100w on each channel. Let me know if you have any other questions."