get two d1 subs. wire each sub to 2 ohm by connecting negative to positive and negative to positive on each sub. this is called series. then, run each amp off of its own set of rca cables and power wires, and you will be running each amp at two ohms producing 1500 watts per amp. the higher the ohm load, the more efficent you will be, which means cooler amps and more power. the bdCP amps produce the same amount of watts at 1 ohm as they do 2 ohm, so you might as well have a higher ohm load to increase efficiency without losing out on any power.