Could it be that the PE included plate amp comes with a specific setup when you order it with the kit? Almost like the one Speaker Power puts into their plate amp? Its weird because Speaker Power is a very well known amps company and they claim that the UM 18-22 cannot handle more than 1000rms without producing a good amount of distortion and clipping. They actually said that they had to set limiters on their 700rms because the UM18 could not handle the 700 watts at some freq. They actually bought and have the UM18-22 with the 4ct sealed box that parts express sells, it was such a popular combo that they wanted to set up an amp for it. They do not recommend getting the 700plate amp without the UM18 eq preset unless a dsp is going to be used to set limiters. They also admited they kept it safe, meaning they could have prob push the woofer a bit more but they wanted to keep the woofer in its optimum performance area. I can actually tell the sub was able to handle more than what they had set on their 700 amp. But I really dont understand how some guys claim they are pushing over 1,500 rms to the sub. With my experience on this sub it cannot handle more than 1,500rms at least not at all freq.