[sanjiwatsuki]

This article is really inaccurate. The impedance isn't a good signal for how much power needs to be pumped into the headphone. The impedance also doesn't act as a good signal for what devices could generate enough volume. It also isn't a good signal for being able to "more accurately and vividly reproduce sound." Almost everything in this section isn't accurate.

Lower impedance headphones are "harder" to drive at the same voltage because they require more current. Often, amplifiers will have lower maximum outputs when driving into a lower impedance.

The sensitivity section isn't too bad but a lot of this article is pure snake oil and bad science. A lot of the amplifier talk in this article also doesn't hold up to scrutiny.