My understanding is that it is 1250w RMS into 8 ohms. The way it was explained to me is that it is the AMP section they use in the DD18 and the PEQ section they use in the SPL line. The difference is that it is able to handle 2 sets of 8 ohm speakers (2 speaker outputs) that brings it down to 4 ohms. The way they advertize it though, I think it is 1250 w into 8 ohms using 1 of the speaker outputs. They rate it talking about 1250 w RMS and 3000 w peak and talking about the different 8 ohms speakers you can use in the velo line....then later they mention that you can add another 8 ohm velodyne speaker as well. In otherwords, I think it is 1250w RMS into one 8 ohm driver, since that is what the wording sounds like to me, and also what the velodyne DD and SPL speakers are. It just happens to be stable down to 4 ohms, so that would make the output even higher. If you go on the velodyne discussion thread you can ask "curt c." he works for them and always answers questions. Maybe I will go ask and get back to you.