Tom, if you're thinking that the bass frequencies necessarily use the most power, that isn't the case; frequency isn't a factor in power requirements. It's simply a question of sound level, and although a bass passage may often be the loudest, this isn't necessarily the case and recordings differ in the distribution of maximum sound levels between frequency ranges. For a simple example, consider that a big double bass playing its lowest 41Hz note at a 70dB loudness level requires a tenth of the power to reproduce it that a little violin playing a 410Hz note at 80dB would need.
