Why do you ask? Are you looking to purchase this sub, or do you already have it?
For subwoofers, the power ratings mean nothing...so don't even look at them. They are completely useless info. The power to drive a subwoofer has much to do with subwoofer design, including enclosure size, as well as driver stability and efficiency.
Due to the extremely inefficient design and small enclosure size of the Supercube, a large amount of power is required to obtain adequate sound levels. But it doesn't mean that it'll be louder than a subwoofer with a 300 watt amp.
For subwoofers, the power ratings mean nothing...so don't even look at them. They are completely useless info. The power to drive a subwoofer has much to do with subwoofer design, including enclosure size, as well as driver stability and efficiency.
Due to the extremely inefficient design and small enclosure size of the Supercube, a large amount of power is required to obtain adequate sound levels. But it doesn't mean that it'll be louder than a subwoofer with a 300 watt amp.