I'm using a QSC RMX2450 to drive a single Ultra and some bass shakers. Granted, this is not an S1500 but like the S1500, it provides more clean power than necessary. If you decide to use the S1500, ensure you calibrate your setup because you will have more power than you need to drive the Ultra to its full potential. I had an S1000 at one time and felt that at times the Ultra could use just a little more than it could provide.