Hi, I bought a set of Audyssey Lower East Side Media Speakers from the United States and now I am relocating to the UK which uses a 220v power supply. The speakers use a 110v power supply and I will need to purchase a step up convertor. However, I understand that the wattage of the step up convertor needs to be able to support the device, i.e. the speakers. May I know the wattage of the speakers so that I can buy the appropriate convertor?