Oscilloscopes measure current and voltage and, through the magic of mathematics, calculate power. Unfortunately, power comes in a large number of guises: instantaneous, real, apparent, and reactive.

Ideally, the power factor should be 1; then the load appears as a resistor to the AC source. However, in the real world, electrical loads not only cause distortions in AC current waveforms, but also ...

Howdy guys - I have an XPA-2 amp hooked up to a pair of B&W683's and am curious how many watts (in real time) I am using. I am not worried about over driving the speakers or worried that the amp is ...