Welcome.
You stated correctly, the sub is powered. As long as the pre or receiver has a sub out or LFE, most do, you can run the sub.
This brings us to the Sherwood. What speakers are you planning on with this sub?
Do you plan on going to surround sound?
The Sherwood is a two channel unit. It does have a sub out, so if 2 channel is your goal it will work.