Are high impedance headphones more efficient to run?

[cedd]

I'm not an audio engineer. From my current understanding a headphone with high impedance, say 300ohm, will draw less current than one with lower impedance, such as 37ohm. Is the end result that higher impedance headphones draw less amps and therefore drain less power?

And does this translate to how hot the gear will run? For instance, will the same amp run hotter with low impedance headphones than higher ones? And will the heat of the cable between amp and headphone also be influenced?

 

[Doodski]

Maximum power transfer occurs when the source impedance and the load impedance are equal.

Using the same amplifier and changing the headphones to a lower impedance will result in more current being required.
Using the same amplifier and changing to a higher impedance headphone will result in lower current but more voltage is required.

Because; Power = Volts x current, then increasing the volts or amps increases the power output from the amp.

A amplifier will run hotter when more current is required to drive the load.

The thermal efficiency or the resistance of the cable causing heat to be produced is generally not a issue with headphones but in extreme circumstances where the cable is wayyyy undersized and there is very high power throughput there may be thermal power losses in the cable but this is a very extreme example that in reality never occurs in real life with headphones. The voice coil in the headphone driver will have a high enough resistance that the power drop will occur over the voice coil and not over the length of the cable.