that's interesting. thing that gets me is the response after 10k cause to me my k601's sounds relaxed at the top-end and lacks a bit if air. only other thing is while they have good imaging it's not as open as my sextetts lp or even DF's. they also didn't have the clarity my sextetts lp and DF's have. that's my only gripe with them but other then that they're great headphone.i mainly use them for ipod duty from now on. works fine off the ipod despite the ridiculous amping claims.

I have always preferred the K601 to the K701, it seems this plot shows why!

i thought i was the only one. yea the k601 is much better over the k701 i think. AKG seems to manage make things sound worst the newer stuff they release.

i believe so. maybe, i think. i know the drivers can't be the same since the 601 is 120ohms and 701 63ohms i believe. i know the foam disc inside over the drivers had lot to do with too and the pad materials. the pads on the k701 is velour while the k601 is velvet(which can probably led to better bass on the k601 and cause the k601 used a thick foam disc that covers the drivers and filters as well).

i'm guessing main difference between them might been pads and the foam disc.

i have to admit though i think my k601 sounds bit smoother over my sextetts lp is one advantage it has. thing is, it can't handle no where near the power my sextetts lp can. driving the k601 off speaker outputs off my 1985 Class A Yamaha R-9 i thought i was gonna kill them when i hit play cause the drivers were flexing so hard with the amount of power and distorting like crazy. even off the headphone jack of my yamaha i can barely touch the volume knob and afraid of killing them. that's why i like using orthos,sextetts and high impedance low-sensitive headphones off of it. afraid of killing something lol. if it's not very high impedance or very low-sensitive i use the headphone jack. speaker outputs are sextetts,DF's and planer magnetic exclusives. other headphones on the headphone jack or another lower powered, power amp.

tad bit cleaner sounding but barely noticeable. i would test farther but if  i do the k601 would probably die.