1000w RMS is the power rating for the amplifier and it doesn't represent the actual power consumption of the unit itself. Some sites are saying that this Velodyne SPL-1200R consumes about 220w in power consumption but to play it safe, get a stepdown transformer with at least 500 watts, it should cost you around RM200 plus. I'm using EKK stepdown transformer and it has two inputs so you can connect two devices to it.

My hd-dvd player, game consoles are all on 110V so I'm just sharing what I know. Well, there are no side effects using a stepdown transformer but do take note cheapo stepdown transformers might run a little hot if you're using it continously so it's better to get an industrial grade stepdown transformer. I'm using EKK myself, switched on 24 hours everyday.

Most subwoofers run pretty hot so make sure it is placed in a well ventilated place to avoid the risk of frying the internal amp. Class A rated amp in subs run even hotter so do take note on this.