"First off, the Ref 1000 is not a 1000 WPC amp, it is a 500 WPC amp (but that is really only for peak/short periods, not continuous)."
REF1000 is rated 1000W/4ohm. By "short periods" only you probably referring to specification of Icepower module 1000ASP used in REF1000 showing only 150W FTC?
First of all in reality it is much better than that (attached test below conducted by DIY member - read below), second of all it is rating of the module WITHOUT ANY HEATSINK!!! REF1000 uses heatsink and I suspect can output 1000W per FTC requirement but it is not even necessary because average music power is only few percent of the peak power.
Originally posted by dmfraser
"I operated a sample 1000ASP on the bench delivering 350W average of pink noise into a 4 ohm load for over one hour with no additional heatsink and the metal case stayed below 55°C.
However, higher levels would make the power supply voltage go down to act as a thermal compensation. Much nicer than just shutting down.
However, with 1214W of sine wave, partly into clipping, after about 35 seconds, the output level would drop to about 600W by the protection circuitry. Remember this is with no additional heatsink."