[Aizura]

Quote:

Prolly too late to post this, the HD448 is designed to work with iPods. (says so on the box)
Sounds decent, although not worth amping due to their low impedance.

 It says it works with iPod because they will sell more this way. An HD800 also "works" with an iPod, but you won't get optimal sound.
And impedance has little to do with the improvement gained from amplification. Grado's for example, are all low impedance, but greatly improve with an amp. Not to mention K701, LCD-2, D7000, etc.

 

[SillyHoney]

My HD555s sounded terrible out of my iPod Touch 3G. They were thin and lifeless sounding. There was a very noticeable difference when I hooked them up to my Xonar DX. So, in my experience, they're best used with an amp.

X2 on the "terrible with iPod"

 

[Zuglufttier]

Just plug the HD650 or HD800 into whatever device you have...
 
Yeah, maybe those will sound a bit better when you add a special amp but those two will sound better than the alternatives mentioned here. The only real showstopper could be the volume... Just go and try it out before you shell out money for a good amp and a mediocre headphone.