Quote Originally Posted by poppachubby
Great point Geoffcin. Patrick, if you go with the AKG watch for the "S" in the model. AKG K240S are the "studio" version at 55ohms. Still difficult for a typical portable to drive, but I'm assuming you're looking for a pair to go with your system. AKG K240M, that's right, "M", are the monitor version and as Geoffcin said, are actually 600 ohms. These are typically used by professionals, as you know they run gear in series and such.
I own both, I have a headphone amp that I use at home and with my portable, however the 240's stay at home.

600 Ohms?....Yikes! You ain't driving that with no Ipod!

The 55 ohm studio should do fine as my 50 ohm Senn's play just fine with my Sansa view.

Also if your going to spend some big $$$, I would audition the cans for a day or more. I was almost sold on the 650's but a day with them left me feeling they were too laid back for my tastes. My 595's are much more lively, (some 'phile types would say agressive), but I like them that way! The 280's are a bit more laid back, but much preferable if your in a uncontrolled noise enviorment.