Originally Posted by jimmers
I think, maybe, that you don't understand the meaning of impedance plots.
That rise in impedance means, among other things, that less power is required around that frequency range.
indeed I have very limited knowledge in this area, so please by all means, correct me if I talk gibberish, it's just how I understand the matter and I would love to understand it better. So my limited understanding is that you have a higher resistance but, as you said, lower current needed to make the headphone loud.
So you have I = V/R (current = Voltage divided by Resistance in Ohms)
The headphone is responsible for R (resistance at this frequency range) and the amp provides the voltage and current, correct?
So while most amps have no problem driving the needed current (in the case of the HD598 I guess not more than maximum of 200mW), they might have an issue providing the right voltage to drive the headphone properly (the HD598 might be a bad example as it is generally easy to drive). Does this make sense?
The reason why I am so hung up about this is, that I want to understand why the Bottlehead Crack drives my T90 so well, while no other amp gives it such a solid response in all frequencies, then I looked at the impedance/frequency curve for the T90 and it's off the charts. I always expected the amount of current and voltage to be the reason behind it. But I might be completely wrong.