Here are some results from one of the members on Termpro:
"OK! Let me give you just a little info on the crunch amps. The GP1500D and the 2500D are rated at Max power not rms. Also these amps are unregulated so the more voltage you give them, the more power you'll get (but they do have high voltage protection around 16.4 volts). The 1500 made 857 watts at 13 volts, but a whopping 1189 at 15.5 volts. This was at 1.1 ohm reactive and all of that power is usable. The GP2500D made 1328 watts at 12.8 volts and 1704 watts at 14.75. These test were also at a 1ohm reactive. So they do more than most people would expect. Oh! The cross-overs in these amps are incredible. They have really good control over your subs. I'll tell you about the 3000 later today!"