Looking around the internet, there haven't been many answers to this questtion. Here is one which doesn't fully explain it:
Power input smaller than output? How can this be?
So I am confused. I know that a transformer (step-up or step-down) can change the voltage and amperage, but without changing the overall power output. So how is it that a speaker (eg Panasonic SC-CMAX5) have a much higher output than input? How can the energy which is put in be less than watt is put out (get it?). The SC-CMAX 5 has a nominal input ("power consumption") of 92W but an output (RMS) of 1000W.
Is it something to do with the RMS or PMPO listed on the spec sheet?
Best Answer
The 92W is an "average" figure while the 1kW is a "maximum". To get a true idea of the maximum input power it could draw, we'd need to look at the information plate on the mains input. There will be capacitors in the power supply for delivering power into peaks. If you actually got it set up and outputting at peak volume it would probably draw >1kW from the mains.
It's not unusual for speaker power outputs to be really misleading, although this is the Panasonic official website and they quote RMS and PMPO. 1kW is quite loud!