Originally Posted by Milhouse74
So out of curiosity, given what I am going to use the headphones for.....should I be shooting lower? Am I looking too high end for mostly iPod and iPad use?
Not really, i guess. There is nothing that make higher end headphones more demanding of power and etc. if their impedance is low, and most of the headphones that you are considering have low impedance (and high sensitivity).
What on the other hand make these headphones differ, are the sound quality they are able to deliver. They are not forgiving against music, and you can hear if a recording is good or bad, whether your source is good, (128k/bit mp3 is BAD) and for example also whether you are using a good amp.
They will definitely never sound worse with an iphone without external, than a cheaper headphone which don't need an amp (in general, as long as the headphone isn't demanding).
You should remember, that some of these phones (eg. the dt990/880 and q701/k701) are also capable and made for studio use for mixing and such.
My dt-880 does not sound bad without and amp, it just sounds significantly better with.