Thanks for that article John. Those power specs are inconsistent however.
At the end of the second paragraph the article describes "Bridged output at clipping was in excess of 300 watts, two channels driven into 8 ohms." while in the list below:
Output at clipping (1 kHz into 8/4 ohms)
1 channel driven: 201/322 watts (23/25.1 dBW)
5 channels driven (8 ohms): 141 watts (21.5 dBW)
7 channels driven (8 ohms): 128 watts
Also in the Stereo Performance section:
Output at clipping (1 kHz, both channels driven)
8/4 ohms: 185/320 watts (22.7/25.1 dBW)
Presumabley he meant bridged output at clipping as as in excess of 300W at 4 ohms not 8 ohms. It would have been more helpful if the author had posted power graphs. I also note that Onkyo's specs "160 watts minimum continuous power per channel, 8 ohm
loads, 2 channels driven at 1 kHz, with a maximum total
harmonic distortion of 0.7% (FTC)"
Note that 5 channels driven is 141wpc so the increase in power in 2 channel is only in the order of 19 watts at 8 ohms. That increase will translate into only a fraction of a decibel with somewhat higher distortion.
