the enginner at phoenix that i spoke to said the 600 will do 1800rms and possibly over 2k easy at 2ohms... call em up and talk to him he was very cool to talk to explained all i wanted to know about the citcuitry of the amps. and yes as i said you can run them down to 1 ohm but quoting hime "not safely" as i said according to him 2 ohms is the safe point for the amps to not fry itself. at 1 ohm the amp will still operate but use caution because it may melt itself down... he specifically said 2 ohms was safe for the amp to do. the 600 is the most underated of the three the 400 doesnt put out a whole tom more than it already does but it does put out more. the 1200 will exceed the 2000 mark and prob do mid 2k range with the trick , but the 600 is def the amp to use this trick with absolutly the most bang for the buck if you can get you hands on them. rlockwood this info was directly from the phoenix engineer and we did bench the amp at just over 1800watts no joke try it yourself bench it and post results i aint scared i did it and saw the results... the 600.1 is an amazing amp capable of way more than it was intended for... and we have had the 600 with this mod running very hard albeit for about a week now and no problems at all with it, ive even been keeping and eye on temps as ive mounted a temp sensor to the amp so i can track it from the front and while yes it is getting warmer than it was its far from melting itself down,, no chance of it right now from temps at least...