i dont know rf amps, but if the amp is 1 ohm stable then go ahead with dual 2 if it isnt go with dual 4 ohm. this is because dual 2 ohms can only be wired to 1 or 4 ohms and if your amp isnt one ohm stable than it could be a waste. so check out your amp an d then make your choice
Its a 2 channel amp. 800x1 @4ohms. get a dual 2 ohm sub, and wire it in series. what kinda sub is it?