Have you ever gone to Best Buy and looked at one of those big name, Chinese made audio receivers?
The specs say 300 watts per channel X 9 channels for a total of 2700 watts output !
Now of course, your 15amp breaker would trip at 1800 watts, assuming nothing else was plugged into the circuit.
And that would assume that the amp was 100% efficient, rather than the more typical 50% efficiency.
Would it surprise you that when people who know how to actually perform a proper industry-standard test on these amps test them, that they only deliver 40 watts per channel, before the amp shuts down, and the thermal overload light locks on?
It always makes me wonder what kind of non-industry-standard tests the manufacturer uses to get those enthusiastic results.