Al, I found this long time ago searching for power test of 200ASC (Icepower module used in my Rowland 102):
"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.
The 200ASC, I was able to operate with sine wave at 100W into 4 ohms continuously. Turning it up, with sine wave, the module would shut down at about 214W.
However, with pink noise at 100Waverage and a 6 db crest factor, the 200ASC would run all day without shut down, until I was tired of tying up one of my Audio Precisions with it. It would also run all day with music, driven hard where the output limiter was set to a peak limit of 210W maximum. That is, the limiter would allow small amounts of clipping. Driven so the limit light in our external optical limiter was on essentially continuously."
It was posted in February 2005 on diyaudio.com forum. Normally 1000ASP is attached to some external heatsinks and should perform better. 200ASC module doesn't have this option.
Music has very low average power - just few percent of peak power. It is not only because of gaps but also because average half loudness is equivalent to 1/10 of power. I would expect long term average power for this 1kW amp to be much less than 100W but it depends on the type of music. Jazz has very low average value but it is much higher for heavy orchestral pieces. Module has 80% efficiency. Assuming two channels at 1kW, supply power is 2x1kW/0.8=2.5kW. It will require 21.7A and 20A circuit breaker should not trip since orchestra forte doesn't last forever. It would be better to put each monoblock on separate breaker or even better - separate phase of 115V.
Class D have also power bandwidth limitations (to protect output filter) but it is way above tweeter's max power. Datasheet for 1000ASP shows 1kW up to 4kHz dropping to 200W at 10kHz. We don't need to worry about it. FTC power, that you mentioned, is shown for 1000ASP as only 150W, but Icepower specifications are very conservative and it is measured without external heatsinks. With 200ASC module FTC power is 55W, but test proved continuous operation at 100W.