This post is not directly related to the K601's really, but just AKG (Harmon Kardon) in general. I received a pair of K701's recently, and for the life of me could not believe how unbalanced the volume seemed to be between the R and L channels. I contacted the support team there and began communicating with a extremely great individual who always responded surprisingly quick (just sent responded to an email I sent him less than 10 minutes ago at 11:15 here on the east coast of the US).
At first, even though I did not have the original purchase receipt he was going to do a return/replacement free of charge. Later, through my own experimentations with putting the K701 pads on my K601, I determined that it was in actuality the ear pads somehow causing the issues. There was obvious differences between the two without anything even playing through the headphones, as the external sounds were blocked much more so in one side compared to the other. So I returned to the support rep with my findings and he promptly shipped me a new pair of ear pads which completely solved my issues!
I can not speak high enough praise, or express how much gratitude I have for their customer service in this situation. I thought that customer service was a dying art so to speak, but my eyes have been opened up to the fact that it does still exist out there, and AKG (Harmon Kardon) are on their game!
As an interesting side note from all of this, I now have two sets of K701 pads sitting here in front of me. I actually had to mix the new and the old to make the two sets, as there was somewhat of an imbalance in the new set as well. So now I have seemingly "transparent" set along with a set which seems to be "darker". I am amazed at the differences between the two sets to be completely honest, and it really makes me wonder just how much, something as simple as a set of stock ear pads, can control the impressions of someone who were to buy a new pair of these headphones. If I were to receive a K701 with the "transparent" set of ear pads, I would be left saying, "wow, those are
extremely sparkly headphones," while on the other hand with the other ear pads I would be left with, "wow, these are pretty balanced headphones. The highs are not as prominent and sparkly as I have read others mention." I know that may sound like some sort of exaggeration possibly, but it really is that much of a difference between the two sets. So now I highly question all of this talk about, "I listened to a set with 1,000 hrs on them and they sounded so much more tame than my 300 hr set!" How much of this is actually something as simple as some sort of variation in the ear pads?
I doubt that most stop to think about possibly swapping the ear pads between one set and the other to see the differences. This is with all 4 ear pads being in new condition by the way.
-Blitz