Came defective from the factory. I had to use Martin logan dynamo and it's been kicking ass so far. Martin Logan just sent me back a brand new grottoi and I got a feeling after using the dynamo for a couple of weeks that that might be enough ( I live in a town house and the neighbors are complaining already). If anyone is interested shoot me an offer since it's still unopened in the box. http://www.us.martinlogan.com/specs/grotto_i.html Just in case her are the specs on the dynamo http://www.us.martinlogan.com/specs/dynamo.html I'll post a system update on my ongoing project soon.