The K1000s were the main reason I joined Head-Case a while ago, so I reckon I’d post a summed-up version of what I posted on my blog after selling mine and borrowing my cousin’s AKGs.
When I sold them I was really unsatisfied with what I heard as a wrong tonal balance, with extremely harsh mids (very different from Grados), impactful but dry bass and somehow subdued treble response. But now my system has been through a complete overhaul – deepak’s old GS-X, Abrahamsen V6.0, M2Tech HiFace and some fancy power cables and interconnects (I’m not a cable guy at all, but they were just sitting in the living room, so hey...).
It’s interesting to see how different it sounds from what I remember. All the aggressiveness is now gone. It’s still not what I’d consider sweet and mellow, but it’s far better now. It all seems better balanced and integrated, with mids going slightly backwards, and bass and treble a bit forward. Bass hits really hard (it’s a bass heavy version BTW), but with surprising texture. The highs, however, which were what I considered to be the Achille’s Heel of the K1000s, for sounding as if they were somehow within the mids, now have their own space in the spectrum. They have presence, extension and a very very good timbre. It really comes to life now, and these headphones finally sound right! It’s very nice to hear how the AKGs can really sing when given a proper system. Thumbs up for the GS-X and the V6.0!
Here's a nice picture BTW: