Captain Ned wrote:
Don't forget that low-Z cans are more current-driven than voltage-driven, thus they need beefier voice coils to absorb the current without melting. That adds weight to the moving part of the diaphragm. High-Z cans need voltage rather than current, thus the voice coils can be lighter, and the resulting moving weight is reduced. Yes, high-Z requires an amp, but all decent cans listening to lossless music should be running through an amp anyway (IMO).
Even in the low-Z case, the output voltage (not current) of the source is supposed to track the input waveform. Low-Z headphones just mean that the source has to be beefier to handle all the current being demanded. If it's insufficiently beefy, then things will become a bit more current-controlled, but that isn't a good thing.
Theoretically, impedance shouldn't have any effect on power demands. 2V/4mA and 0.5V/16mA represent the same amount of power going into the driver, and if the efficiency of the driver is the same, then the voice coil dissipation demands are the same. A lot of things change when you go from 16 ohms to 600 ohms (and efficiency and power handling aren't going to be unaffected), but they're more subtle than that, and I can think of ways for the change to affect either variable in either direction.
Thanks for explaining that. I appreciate it.
No problem, I'm happy it was helpful.