I was supplying enough for the DD3515, and had no room for upgrade. To order another SC DD3515 would be more than what I was willing to pay ( I got the DC Lv5 18s for cheaper) and I would still only be able to run around 5kw total. I've always wanted a big build, and with these 18s I'm planning to run anywhere from 8kwrms to 10kwrms. I'll be buying the amp near the end of August, and will be running it at 4ohm until My electrical is up to par, which looks to be ready by December.