depends your amp is stable down to 2 ohms. so that means at 2 ohms the sub is going to put out its max amount of power and at 4ohms it will run at usually half that power maybe a bit more. the ideal thing to do is to either get a dual 4 ohm sub so you can wire it to be 2 ohms or get a amp that is stable at 1 ohm. for now you can run it at 4 ohms wich will be the most efficient but also a lot more quiet then running it at 2 ohms or 1